Merge branch 'release/materials_featurette' into materials_featurette/mirrors

17 files changed, 436 insertions, 57 deletions

diff --git a/.github/ISSUE_TEMPLATE/bug.yaml b/.github/ISSUE_TEMPLATE/bug.yaml
new file mode 100644
index 0000000000..41208e8bf5
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/bug.yaml
@@ -0,0 +1,36 @@
+name: Bug report
+description: Viewer bug report
+labels: [bug, triage]
+body:
+- type: markdown
+  attributes:
+    value: |
+      - Write a descriptive bug title above.
+      - Search [open](https://github.com/secondlife/viewer/issues?q=is%3Aopen+label%3Abug+is%3Aissue) bugs to ensure that the issue has not already been identified.
+
+- type: textarea
+  attributes:
+    label: Environment
+    description: About Second Life Text
+    placeholder: ex. Second Life Test 7.1.3.240191747 (64bit) ...
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Description
+    description: Explain the problem.
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Reproduction steps
+    description: Steps to reproduce this bug
+    placeholder: |
+      1. First step
+      2. Second step
+      Expected: ...
+      Actual: ...
+  validations:
+    required: true
diff --git a/.github/ISSUE_TEMPLATE/enhancement.md b/.github/ISSUE_TEMPLATE/enhancement.md
new file mode 100644
index 0000000000..dd40478811
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/enhancement.md
@@ -0,0 +1,12 @@
+---
+name: Enhancement
+about: New feature or enhancement
+title: New Feature
+labels: enhancement, triage
+---
+
+_What does this feature/enhancement do? Why is it needed?_
+
+## Test Plan
+
+_Include information, such as guidance and test scenarios, QA will need to test this feature._
diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index dee1ca24ab..70a3747b71 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -4,8 +4,8 @@ on:
   workflow_dispatch:
   pull_request:
   push:
-    branches: ["*"]
-    tags: ["*"]
+    branches: ["main", "release/*", "project/*"]
+    tags: ["Second_Life_*"]
 
 jobs:
   build:
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000000..6bd8a2b74c
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,76 @@
+# Contributor guidelines
+
+Thanks for your interest in contributing to Second Life! This document
+summarizes some of the most important points for people looking to contribute
+to the platform especially those looking to provide bug reports and code
+changes.
+
+## Table of contents
+
+- [Communication](#communication)
+- [Reporting bugs and requesting features](#reporting-bugs-and-requesting-features)
+- [Contributing pull requests](#contributing-pull-requests)
+
+## Communication
+
+Second Life has multiple channels for communication. Some of these channels are
+more end-user focused, while others are more tailored for
+developer-to-developer or support.
+
+- [feedback.secondlife.com][] is Second Life's primary community engagement
+  forum. Ideas and bug reports should be placed here unless they relate to
+  ongoing development issues and developer-to-developer communication.
+- [Public user groups][slug] are held on a regular basis, including those for
+  discussing open source development, content creation, server topics and more.
+- [Github issues][] provide a means for staff to organize their
+  work and collaborate with other developers. By default most user-facing
+  discussions should happen on [feedback.secondlife.com][] so that they are
+  visible to more people, can build consensus, and be placed onto our public
+  roadmap. Github issues are useful for collaboration between viewer forks
+  and the official upstream and when engineering-specific and technical
+  collaboration is beneficial. 
+- [Official forums][] exist for many topics including content creation,
+   scripting, social topics and more. 
+- The [opensource-dev mailing list][] is useful for announcements and
+  discussion between viewer maintainers. 
+
+
+## Reporting bugs and requesting features
+
+Report bugs and provide ideas for features using the respective board on Second
+Life's feedback portal:
+
+- [Features](https://feedback.secondlife.com/feature-requests)
+- [Scripting bugs](https://feedback.secondlife.com/scripting-bugs)
+- [Scripting features](https://feedback.secondlife.com/scripting-features)
+- [Server bugs](https://feedback.secondlife.com/scripting-bugs)
+- [Viewer bugs](https://feedback.secondlife.com/bug-reports)
+- [Web/Marketplace bugs](https://feedback.secondlife.com/web-bugs)
+- [Web/Marketplace features](https://feedback.secondlife.com/web-features)
+
+Creating posts on feedback.secondlife.com is important as it allows the greatest
+exposure and input from Second Life users. It also allows Linden Lab staff to
+place work on a single public roadmap.
+
+Issues created on feedback.secondlife.com are imported onto Github after they
+have been reviewed by staff and accepted. 
+
+## Contributing pull requests
+
+If you wish to contribute a new pull request, please ensure that:
+
+- You talk to other developers about how best to implement the work.
+- The functionality is desired. Be sure to talk to users and Second Life staff to ensure
+  the work is a good idea and will be accepted.
+- The work is high quality and the PR follows [PR etiquette][]
+- You have tested the work locally
+
+The [Git Style Guide](https://github.com/agis/git-style-guide) is also a good
+reference for best git practices.
+
+[feedback.secondlife.com]: https://feedback.secondlife.com
+[slug]: https://community.secondlife.com/blogs/entry/6509-introducing-the-second-life-public-calendar/
+[PR etiquette]: https://gist.github.com/mikepea/863f63d6e37281e329f8
+[Github issues]: https://github.com/secondlife/viewer/issues
+[Official forums]: https://community.secondlife.com/forums/
+[opensource-dev mailing list]: https://wiki.secondlife.com/wiki/OpenSource-Dev
diff --git a/README.md b/README.md
index c57140af9c..1e40c7f9f5 100644
--- a/README.md
+++ b/README.md
@@ -35,9 +35,10 @@ Third party maintained forks, which include Linux compatible builds, are indexed
 ## Contribute
 
 Help make Second Life better! You can get involved with improvements by filing bugs, suggesting enhancements, submitting
-pull requests and more. See the [open source portal][] for details.
+pull requests and more. See the [CONTRIBUTING][] and the [open source portal][] for details.
 
 [Second Life]: https://secondlife.com/
 [download]: https://secondlife.com/support/downloads/
 [tpv]: http://wiki.secondlife.com/wiki/Third_Party_Viewer_Directory
 [open source portal]: http://wiki.secondlife.com/wiki/Open_Source_Portal
+[contributing]: https://github.com/secondlife/viewer/blob/main/CONTRIBUTING.md
diff --git a/doc/testplans/pbr_terrain_feature_gating.md b/doc/testplans/pbr_terrain_feature_gating.md
new file mode 100644
index 0000000000..13108c1534
--- /dev/null
+++ b/doc/testplans/pbr_terrain_feature_gating.md
@@ -0,0 +1,22 @@
+# PBR Terrain Feature Gating
+
+PBR terrain should have lower detail on lower graphics settings. PBR terrain will also not show emissive textures on some machines (like Macs) which do not support more than 16 textures.
+
+## Triplanar Mapping
+
+Triplanar mapping improves the texture repeats on the sides of terrain slopes.
+
+Availability of Triplanar mapping:
+
+- Medium-High and below: No triplanar mapping
+- High and above: Triplanar mapping
+
+## PBR Textures
+
+At the highest graphics support level, PBR terrain supports all PBR textures.
+
+Availability of PBR textures varies by machine and graphics setting:
+
+- Low: Base color only (looks similar to texture terrain)
+- Medium-Low, and machines that do not support greater than 16 textures such as Macs: All PBR textures enabled except emissive textures.
+- Medium: All PBR textures enabled
diff --git a/indra/newview/app_settings/settings.xml b/indra/newview/app_settings/settings.xml
index 589d079acd..6ec9a9acc5 100644
--- a/indra/newview/app_settings/settings.xml
+++ b/indra/newview/app_settings/settings.xml
@@ -10833,10 +10833,21 @@
       <key>Value</key>
       <integer>0</integer>
     </map>
+    <key>RenderTerrainPBRForce</key>
+    <map>
+      <key>Comment</key>
+      <string>Force-load PBR terrain if enabled</string>
+      <key>Persist</key>
+      <integer>0</integer>
+      <key>Type</key>
+      <string>Boolean</string>
+      <key>Value</key>
+      <integer>0</integer>
+    </map>
     <key>RenderTerrainPBRDetail</key>
     <map>
       <key>Comment</key>
-      <string>Detail level for PBR terrain. 0 is full detail. Negative values drop rendering features in accordance with the GLTF specification, which reduces the number of texture binds. Some Intel and Mac graphics drivers do not support more than 16 texture binds. Because PBR terrain exceeds this limit at the highest detail level, reducing texture binds is necessary for compatibility.</string>
+      <string>Detail level for PBR terrain. 0 is full detail. Negative values drop rendering features, in accordance with the GLTF specification when possible, which reduces the number of texture binds.</string>
       <key>Persist</key>
       <integer>1</integer>
       <key>Type</key>
diff --git a/indra/newview/app_settings/shaders/class1/deferred/pbrterrainF.glsl b/indra/newview/app_settings/shaders/class1/deferred/pbrterrainF.glsl
index db03e0885c..c83a6be85d 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/pbrterrainF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/pbrterrainF.glsl
@@ -26,6 +26,9 @@
 /*[EXTRA_CODE_HERE]*/
 
 #define TERRAIN_PBR_DETAIL_EMISSIVE 0
+#define TERRAIN_PBR_DETAIL_OCCLUSION -1
+#define TERRAIN_PBR_DETAIL_NORMAL -2
+#define TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS -3
 
 #if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3
 #define TerrainCoord vec4[2]
@@ -38,7 +41,6 @@
 #define MIX_Z    1 << 5
 #define MIX_W    1 << 6
 
-// TODO: Decide if this struct needs to be declared
 struct TerrainMix
 {
     vec4 weight;
@@ -47,12 +49,17 @@ struct TerrainMix
 
 TerrainMix get_terrain_mix_weights(float alpha1, float alpha2, float alphaFinal);
 
-// TODO: Decide if this struct needs to be declared
 struct PBRMix
 {
     vec4 col;       // RGB color with alpha, linear space
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
     vec3 orm;       // Occlusion, roughness, metallic
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+    vec2 rm;        // Roughness, metallic
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
     vec3 vNt;       // Unpacked normal texture sample, vector
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     vec3 emissive;  // RGB emissive color, linear space
 #endif
@@ -63,13 +70,21 @@ PBRMix init_pbr_mix();
 PBRMix terrain_sample_and_multiply_pbr(
     TerrainCoord terrain_coord
     , sampler2D tex_col
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
     , sampler2D tex_orm
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
     , sampler2D tex_vNt
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     , sampler2D tex_emissive
 #endif
     , vec4 factor_col
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
     , vec3 factor_orm
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+    , vec2 factor_rm
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     , vec3 factor_emissive
 #endif
@@ -81,21 +96,23 @@ out vec4 frag_data[4];
 
 uniform sampler2D alpha_ramp;
 
-// *TODO: More configurable quality level which disables PBR features on machines
-// with limited texture availability
 // https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#additional-textures
 uniform sampler2D detail_0_base_color;
 uniform sampler2D detail_1_base_color;
 uniform sampler2D detail_2_base_color;
 uniform sampler2D detail_3_base_color;
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
 uniform sampler2D detail_0_normal;
 uniform sampler2D detail_1_normal;
 uniform sampler2D detail_2_normal;
 uniform sampler2D detail_3_normal;
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
 uniform sampler2D detail_0_metallic_roughness;
 uniform sampler2D detail_1_metallic_roughness;
 uniform sampler2D detail_2_metallic_roughness;
 uniform sampler2D detail_3_metallic_roughness;
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
 uniform sampler2D detail_0_emissive;
 uniform sampler2D detail_1_emissive;
@@ -104,8 +121,10 @@ uniform sampler2D detail_3_emissive;
 #endif
 
 uniform vec4[4] baseColorFactors; // See also vertex_color in pbropaqueV.glsl
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
 uniform vec4 metallicFactors;
 uniform vec4 roughnessFactors;
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
 uniform vec3[4] emissiveColors;
 #endif
@@ -139,6 +158,7 @@ void main()
 
     TerrainMix tm = get_terrain_mix_weights(alpha1, alpha2, alphaFinal);
 
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
     // RGB = Occlusion, Roughness, Metal
     // default values, see LLViewerTexture::sDefaultPBRORMImagep
     //   occlusion 1.0
@@ -149,6 +169,13 @@ void main()
     orm_factors[1] = vec3(1.0, roughnessFactors.y, metallicFactors.y);
     orm_factors[2] = vec3(1.0, roughnessFactors.z, metallicFactors.z);
     orm_factors[3] = vec3(1.0, roughnessFactors.w, metallicFactors.w);
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+    vec2[4] rm_factors;
+    rm_factors[0] = vec2(roughnessFactors.x, metallicFactors.x);
+    rm_factors[1] = vec2(roughnessFactors.y, metallicFactors.y);
+    rm_factors[2] = vec2(roughnessFactors.z, metallicFactors.z);
+    rm_factors[3] = vec2(roughnessFactors.w, metallicFactors.w);
+#endif
 
     PBRMix mix = init_pbr_mix();
     PBRMix mix2;
@@ -158,13 +185,21 @@ void main()
         mix2 = terrain_sample_and_multiply_pbr(
             terrain_texcoord
             , detail_0_base_color
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
             , detail_0_metallic_roughness
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
             , detail_0_normal
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
             , detail_0_emissive
 #endif
             , baseColorFactors[0]
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
             , orm_factors[0]
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+            , rm_factors[0]
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
             , emissiveColors[0]
 #endif
@@ -180,13 +215,21 @@ void main()
         mix2 = terrain_sample_and_multiply_pbr(
             terrain_texcoord
             , detail_1_base_color
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
             , detail_1_metallic_roughness
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
             , detail_1_normal
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
             , detail_1_emissive
 #endif
             , baseColorFactors[1]
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
             , orm_factors[1]
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+            , rm_factors[1]
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
             , emissiveColors[1]
 #endif
@@ -202,13 +245,21 @@ void main()
         mix2 = terrain_sample_and_multiply_pbr(
             terrain_texcoord
             , detail_2_base_color
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
             , detail_2_metallic_roughness
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
             , detail_2_normal
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
             , detail_2_emissive
 #endif
             , baseColorFactors[2]
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
             , orm_factors[2]
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+            , rm_factors[2]
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
             , emissiveColors[2]
 #endif
@@ -224,13 +275,21 @@ void main()
         mix2 = terrain_sample_and_multiply_pbr(
             terrain_texcoord
             , detail_3_base_color
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
             , detail_3_metallic_roughness
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
             , detail_3_normal
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
             , detail_3_emissive
 #endif
             , baseColorFactors[3]
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
             , orm_factors[3]
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+            , rm_factors[3]
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
             , emissiveColors[3]
 #endif
@@ -248,6 +307,7 @@ void main()
     }
     float base_color_factor_alpha = terrain_mix(tm, vec4(baseColorFactors[0].z, baseColorFactors[1].z, baseColorFactors[2].z, baseColorFactors[3].z));
 
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
     // from mikktspace.com
     vec3 vNt = mix.vNt;
     vec3 vN = vary_normal;
@@ -257,6 +317,10 @@ void main()
     vec3 tnorm = normalize( vNt.x * vT + vNt.y * vB + vNt.z * vN );
 
     tnorm *= gl_FrontFacing ? 1.0 : -1.0;
+#else
+    vec3 tnorm = vary_normal;
+    tnorm *= gl_FrontFacing ? 1.0 : -1.0;
+#endif
    
 
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
@@ -264,8 +328,16 @@ void main()
 #else
 #define emissive vec3(0)
 #endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
+#define orm mix.orm
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+#define orm vec3(1.0, mix.rm)
+#else
+// Matte plastic potato terrain
+#define orm vec3(1.0, 1.0, 0.0)
+#endif
     frag_data[0] = max(vec4(mix.col.xyz, 0.0), vec4(0));                                                   // Diffuse
-    frag_data[1] = max(vec4(mix.orm.rgb, base_color_factor_alpha), vec4(0));                                    // PBR linear packed Occlusion, Roughness, Metal.
+    frag_data[1] = max(vec4(orm.rgb, base_color_factor_alpha), vec4(0));                                    // PBR linear packed Occlusion, Roughness, Metal.
     frag_data[2] = max(vec4(encode_normal(tnorm), base_color_factor_alpha, GBUFFER_FLAG_HAS_PBR), vec4(0)); // normal, environment intensity, flags
     frag_data[3] = max(vec4(emissive,0), vec4(0));                                                // PBR sRGB Emissive
 }
diff --git a/indra/newview/app_settings/shaders/class1/deferred/pbrterrainUtilF.glsl b/indra/newview/app_settings/shaders/class1/deferred/pbrterrainUtilF.glsl
index 316b751590..935c3f9301 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/pbrterrainUtilF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/pbrterrainUtilF.glsl
@@ -47,6 +47,9 @@
  */
 
 #define TERRAIN_PBR_DETAIL_EMISSIVE 0
+#define TERRAIN_PBR_DETAIL_OCCLUSION -1
+#define TERRAIN_PBR_DETAIL_NORMAL -2
+#define TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS -3
 
 in vec3 vary_vertex_normal;
 
@@ -75,8 +78,14 @@ vec3 srgb_to_linear(vec3 c);
 struct PBRMix
 {
     vec4 col;       // RGB color with alpha, linear space
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
     vec3 orm;       // Occlusion, roughness, metallic
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+    vec2 rm;        // Roughness, metallic
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
     vec3 vNt;       // Unpacked normal texture sample, vector
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     vec3 emissive;  // RGB emissive color, linear space
 #endif
@@ -86,8 +95,14 @@ PBRMix init_pbr_mix()
 {
     PBRMix mix;
     mix.col = vec4(0);
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
     mix.orm = vec3(0);
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+    mix.rm = vec2(0);
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
     mix.vNt = vec3(0);
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     mix.emissive = vec3(0);
 #endif
@@ -105,8 +120,14 @@ PBRMix mix_pbr(PBRMix mix1, PBRMix mix2, float mix2_weight)
 {
     PBRMix mix;
     mix.col      = mix1.col      + (mix2.col      * mix2_weight);
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
     mix.orm      = mix1.orm      + (mix2.orm      * mix2_weight);
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+    mix.rm       = mix1.rm       + (mix2.rm       * mix2_weight);
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
     mix.vNt      = mix1.vNt      + (mix2.vNt      * mix2_weight);
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     mix.emissive = mix1.emissive + (mix2.emissive * mix2_weight);
 #endif
@@ -116,8 +137,12 @@ PBRMix mix_pbr(PBRMix mix1, PBRMix mix2, float mix2_weight)
 PBRMix sample_pbr(
     vec2 uv
     , sampler2D tex_col
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
     , sampler2D tex_orm
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
     , sampler2D tex_vNt
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     , sampler2D tex_emissive
 #endif
@@ -126,8 +151,14 @@ PBRMix sample_pbr(
     PBRMix mix;
     mix.col = texture(tex_col, uv);
     mix.col.rgb = srgb_to_linear(mix.col.rgb);
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
     mix.orm = texture(tex_orm, uv).xyz;
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+    mix.rm = texture(tex_orm, uv).yz;
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
     mix.vNt = texture(tex_vNt, uv).xyz*2.0-1.0;
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     mix.emissive = srgb_to_linear(texture(tex_emissive, uv).xyz);
 #endif
@@ -254,8 +285,12 @@ PBRMix terrain_sample_pbr(
     TerrainCoord terrain_coord
     , TerrainTriplanar tw
     , sampler2D tex_col
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
     , sampler2D tex_orm
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
     , sampler2D tex_vNt
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     , sampler2D tex_emissive
 #endif
@@ -272,14 +307,20 @@ PBRMix terrain_sample_pbr(
         PBRMix mix_x = sample_pbr(
             get_uv_x()
             , tex_col
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
             , tex_orm
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
             , tex_vNt
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
             , tex_emissive
 #endif
             );
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
         // Triplanar-specific normal texture fix
         mix_x.vNt = _t_normal_post_x(mix_x.vNt);
+#endif
         mix = mix_pbr(mix, mix_x, tw.weight.x);
         break;
     default:
@@ -292,14 +333,20 @@ PBRMix terrain_sample_pbr(
         PBRMix mix_y = sample_pbr(
             get_uv_y()
             , tex_col
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
             , tex_orm
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
             , tex_vNt
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
             , tex_emissive
 #endif
             );
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
         // Triplanar-specific normal texture fix
         mix_y.vNt = _t_normal_post_y(mix_y.vNt);
+#endif
         mix = mix_pbr(mix, mix_y, tw.weight.y);
         break;
     default:
@@ -312,15 +359,21 @@ PBRMix terrain_sample_pbr(
         PBRMix mix_z = sample_pbr(
             get_uv_z()
             , tex_col
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
             , tex_orm
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
             , tex_vNt
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
             , tex_emissive
 #endif
             );
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
         // Triplanar-specific normal texture fix
         // *NOTE: Bottom face has not been tested
         mix_z.vNt = _t_normal_post_z(mix_z.vNt);
+#endif
         mix = mix_pbr(mix, mix_z, tw.weight.z);
         break;
     default:
@@ -341,7 +394,11 @@ PBRMix terrain_sample_pbr(
 PBRMix multiply_factors_pbr(
     PBRMix mix_in
     , vec4 factor_col
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
     , vec3 factor_orm
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+    , vec2 factor_rm
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     , vec3 factor_emissive
 #endif
@@ -349,7 +406,11 @@ PBRMix multiply_factors_pbr(
 {
     PBRMix mix = mix_in;
     mix.col *= factor_col;
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
     mix.orm *= factor_orm;
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+    mix.rm *= factor_rm;
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     mix.emissive *= factor_emissive;
 #endif
@@ -359,13 +420,21 @@ PBRMix multiply_factors_pbr(
 PBRMix terrain_sample_and_multiply_pbr(
     TerrainCoord terrain_coord
     , sampler2D tex_col
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
     , sampler2D tex_orm
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
     , sampler2D tex_vNt
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     , sampler2D tex_emissive
 #endif
     , vec4 factor_col
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
     , vec3 factor_orm
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+    , vec2 factor_rm
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
     , vec3 factor_emissive
 #endif
@@ -377,8 +446,12 @@ PBRMix terrain_sample_and_multiply_pbr(
         , _t_triplanar()
 #endif
         , tex_col
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
         , tex_orm
+#endif
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
         , tex_vNt
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
         , tex_emissive
 #endif
@@ -386,7 +459,11 @@ PBRMix terrain_sample_and_multiply_pbr(
 
     mix = multiply_factors_pbr(mix
         , factor_col
+#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION)
         , factor_orm
+#elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+        , factor_rm
+#endif
 #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
         , factor_emissive
 #endif
diff --git a/indra/newview/featuretable.txt b/indra/newview/featuretable.txt
index c341097dfc..965391b5cf 100644
--- a/indra/newview/featuretable.txt
+++ b/indra/newview/featuretable.txt
@@ -1,4 +1,4 @@
-version 59
+version 60
 // The version number above should be incremented IF AND ONLY IF some
 // change has been made that is sufficiently important to justify
 // resetting the graphics preferences of all users to the recommended
@@ -96,6 +96,7 @@ RenderReflectionsEnabled    1   1
 RenderReflectionProbeDetail	1	0
 RenderTerrainDetail			1	0
 RenderTerrainLODFactor		1	1
+RenderTerrainPBRDetail      1   -4
 RenderTerrainPBRPlanarSampleCount 1   1
 RenderTreeLODFactor			1	0
 RenderVolumeLODFactor		1	1.125
@@ -126,6 +127,7 @@ RenderReflectionsEnabled    1   1
 RenderReflectionProbeDetail	1	0
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	1.0
+RenderTerrainPBRDetail      1   -1
 RenderTerrainPBRPlanarSampleCount 1   1
 RenderTreeLODFactor			1	0.5
 RenderVolumeLODFactor		1	1.125
@@ -154,6 +156,7 @@ RenderLocalLightCount		1	512
 RenderTransparentWater      1   0
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
+RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   1
 RenderTreeLODFactor			1	0.5
 RenderVolumeLODFactor		1	1.25
@@ -184,6 +187,7 @@ RenderLocalLightCount		1	1024
 RenderTransparentWater      1   1
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
+RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   1
 RenderTreeLODFactor			1	0.5
 RenderVolumeLODFactor		1	1.375
@@ -214,6 +218,7 @@ RenderLocalLightCount		1	2048
 RenderTransparentWater      1   1
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
+RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   3
 RenderTreeLODFactor			1	0.5
 RenderVolumeLODFactor		1	1.5
@@ -243,6 +248,7 @@ RenderMaxPartCount			1	4096
 RenderLocalLightCount		1	4096
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
+RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   3
 RenderTransparentWater		1	1
 RenderTreeLODFactor			1	0.5
@@ -272,6 +278,7 @@ RenderLocalLightCount		1	8192
 RenderMaxPartCount			1	8192
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
+RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   3
 RenderTransparentWater		1	1
 RenderTreeLODFactor			1	1.0
diff --git a/indra/newview/featuretable_mac.txt b/indra/newview/featuretable_mac.txt
index ac0ac15bd0..61cde82512 100644
--- a/indra/newview/featuretable_mac.txt
+++ b/indra/newview/featuretable_mac.txt
@@ -1,4 +1,4 @@
-version 56
+version 57
 // The version number above should be incremented IF AND ONLY IF some
 // change has been made that is sufficiently important to justify
 // resetting the graphics preferences of all users to the recommended
@@ -45,6 +45,7 @@ RenderObjectBump			1	1
 RenderLocalLightCount		1	4096
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
+RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   3
 RenderTransparentWater		1	1
 RenderTreeLODFactor			1	1.0
@@ -90,6 +91,7 @@ RenderLocalLightCount		1	8
 RenderMaxPartCount			1	0
 RenderTerrainDetail			1	0
 RenderTerrainLODFactor		1	1
+RenderTerrainPBRDetail      1   -4
 RenderTerrainPBRPlanarSampleCount 1   1
 RenderTransparentWater		1	0
 RenderTreeLODFactor			1	0
@@ -120,6 +122,7 @@ RenderMaxPartCount			1	2048
 RenderLocalLightCount		1	256
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	1.0
+RenderTerrainPBRDetail      1   -1
 RenderTerrainPBRPlanarSampleCount 1   1
 RenderTransparentWater		1	1
 RenderTreeLODFactor			1	0.5
@@ -150,6 +153,7 @@ RenderMaxPartCount			1	4096
 RenderLocalLightCount		1	512
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
+RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   1
 RenderTransparentWater		1	1
 RenderTreeLODFactor			1	0.5
@@ -180,6 +184,7 @@ RenderMaxPartCount			1	4096
 RenderLocalLightCount		1	1024
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
+RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   1
 RenderTransparentWater		1	1
 RenderTreeLODFactor			1	0.5
@@ -210,6 +215,7 @@ RenderMaxPartCount			1	4096
 RenderLocalLightCount		1	2048
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
+RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   3
 RenderTransparentWater		1	1
 RenderTreeLODFactor			1	0.5
@@ -240,6 +246,7 @@ RenderMaxPartCount			1	4096
 RenderLocalLightCount		1	4096
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
+RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   3
 RenderTransparentWater		1	1
 RenderTreeLODFactor			1	0.5
@@ -269,6 +276,7 @@ RenderLocalLightCount		1	8192
 RenderMaxPartCount			1	8192
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
+RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   3
 RenderTransparentWater		1	1
 RenderTreeLODFactor			1	1.0
diff --git a/indra/newview/lldrawpoolterrain.cpp b/indra/newview/lldrawpoolterrain.cpp
index fc8e9fcfe5..3a943f27f6 100644
--- a/indra/newview/lldrawpoolterrain.cpp
+++ b/indra/newview/lldrawpoolterrain.cpp
@@ -54,8 +54,6 @@
 const F32 DETAIL_SCALE = 1.f/16.f;
 int DebugDetailMap = 0;
 
-const S32 PBR_DETAIL_EMISSIVE = 0;
-
 S32 LLDrawPoolTerrain::sPBRDetailMode = 0;
 F32 LLDrawPoolTerrain::sDetailScale = DETAIL_SCALE;
 F32 LLDrawPoolTerrain::sPBRDetailScale = DETAIL_SCALE;
@@ -399,31 +397,37 @@ void LLDrawPoolTerrain::renderFullShaderPBR(BOOL local_materials)
         gGL.getTexUnit(detail_basecolor[i])->setTextureAddressMode(LLTexUnit::TAM_WRAP);
         gGL.getTexUnit(detail_basecolor[i])->activate();
 
-        detail_normal[i] = sShader->enableTexture(LLViewerShaderMgr::TERRAIN_DETAIL0_NORMAL + i);
-        if (detail_normal_texturep)
-        {
-            gGL.getTexUnit(detail_normal[i])->bind(detail_normal_texturep);
-        }
-        else
+        if (sPBRDetailMode >= TERRAIN_PBR_DETAIL_NORMAL)
         {
-            gGL.getTexUnit(detail_normal[i])->bind(LLViewerFetchedTexture::sFlatNormalImagep);
+            detail_normal[i] = sShader->enableTexture(LLViewerShaderMgr::TERRAIN_DETAIL0_NORMAL + i);
+            if (detail_normal_texturep)
+            {
+                gGL.getTexUnit(detail_normal[i])->bind(detail_normal_texturep);
+            }
+            else
+            {
+                gGL.getTexUnit(detail_normal[i])->bind(LLViewerFetchedTexture::sFlatNormalImagep);
+            }
+            gGL.getTexUnit(detail_normal[i])->setTextureAddressMode(LLTexUnit::TAM_WRAP);
+            gGL.getTexUnit(detail_normal[i])->activate();
         }
-        gGL.getTexUnit(detail_normal[i])->setTextureAddressMode(LLTexUnit::TAM_WRAP);
-        gGL.getTexUnit(detail_normal[i])->activate();
 
-        detail_metalrough[i] = sShader->enableTexture(LLViewerShaderMgr::TERRAIN_DETAIL0_METALLIC_ROUGHNESS + i);
-        if (detail_metalrough_texturep)
+        if (sPBRDetailMode >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
         {
-            gGL.getTexUnit(detail_metalrough[i])->bind(detail_metalrough_texturep);
-        }
-        else
-        {
-            gGL.getTexUnit(detail_metalrough[i])->bind(LLViewerFetchedTexture::sWhiteImagep);
+            detail_metalrough[i] = sShader->enableTexture(LLViewerShaderMgr::TERRAIN_DETAIL0_METALLIC_ROUGHNESS + i);
+            if (detail_metalrough_texturep)
+            {
+                gGL.getTexUnit(detail_metalrough[i])->bind(detail_metalrough_texturep);
+            }
+            else
+            {
+                gGL.getTexUnit(detail_metalrough[i])->bind(LLViewerFetchedTexture::sWhiteImagep);
+            }
+            gGL.getTexUnit(detail_metalrough[i])->setTextureAddressMode(LLTexUnit::TAM_WRAP);
+            gGL.getTexUnit(detail_metalrough[i])->activate();
         }
-        gGL.getTexUnit(detail_metalrough[i])->setTextureAddressMode(LLTexUnit::TAM_WRAP);
-        gGL.getTexUnit(detail_metalrough[i])->activate();
 
-        if (sPBRDetailMode >= PBR_DETAIL_EMISSIVE)
+        if (sPBRDetailMode >= TERRAIN_PBR_DETAIL_EMISSIVE)
         {
             detail_emissive[i] = sShader->enableTexture(LLViewerShaderMgr::TERRAIN_DETAIL0_EMISSIVE + i);
             if (detail_emissive_texturep)
@@ -499,9 +503,12 @@ void LLDrawPoolTerrain::renderFullShaderPBR(BOOL local_materials)
         minimum_alphas[i] = min_alpha;
     }
     shader->uniform4fv(LLShaderMgr::TERRAIN_BASE_COLOR_FACTORS, terrain_material_count, (F32*)base_color_factors);
-    shader->uniform4f(LLShaderMgr::TERRAIN_METALLIC_FACTORS, metallic_factors[0], metallic_factors[1], metallic_factors[2], metallic_factors[3]);
-    shader->uniform4f(LLShaderMgr::TERRAIN_ROUGHNESS_FACTORS, roughness_factors[0], roughness_factors[1], roughness_factors[2], roughness_factors[3]);
-    if (sPBRDetailMode >= PBR_DETAIL_EMISSIVE)
+    if (sPBRDetailMode >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+    {
+        shader->uniform4f(LLShaderMgr::TERRAIN_METALLIC_FACTORS, metallic_factors[0], metallic_factors[1], metallic_factors[2], metallic_factors[3]);
+        shader->uniform4f(LLShaderMgr::TERRAIN_ROUGHNESS_FACTORS, roughness_factors[0], roughness_factors[1], roughness_factors[2], roughness_factors[3]);
+    }
+    if (sPBRDetailMode >= TERRAIN_PBR_DETAIL_EMISSIVE)
     {
         shader->uniform3fv(LLShaderMgr::TERRAIN_EMISSIVE_COLORS, terrain_material_count, (F32*)emissive_colors);
     }
@@ -521,9 +528,15 @@ void LLDrawPoolTerrain::renderFullShaderPBR(BOOL local_materials)
     for (U32 i = 0; i < terrain_material_count; ++i)
     {
         sShader->disableTexture(LLViewerShaderMgr::TERRAIN_DETAIL0_BASE_COLOR + i);
-        sShader->disableTexture(LLViewerShaderMgr::TERRAIN_DETAIL0_NORMAL + i);
-        sShader->disableTexture(LLViewerShaderMgr::TERRAIN_DETAIL0_METALLIC_ROUGHNESS + i);
-        if (sPBRDetailMode >= PBR_DETAIL_EMISSIVE)
+        if (sPBRDetailMode >= TERRAIN_PBR_DETAIL_NORMAL)
+        {
+            sShader->disableTexture(LLViewerShaderMgr::TERRAIN_DETAIL0_NORMAL + i);
+        }
+        if (sPBRDetailMode >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+        {
+            sShader->disableTexture(LLViewerShaderMgr::TERRAIN_DETAIL0_METALLIC_ROUGHNESS + i);
+        }
+        if (sPBRDetailMode >= TERRAIN_PBR_DETAIL_EMISSIVE)
         {
             sShader->disableTexture(LLViewerShaderMgr::TERRAIN_DETAIL0_EMISSIVE + i);
         }
@@ -532,15 +545,21 @@ void LLDrawPoolTerrain::renderFullShaderPBR(BOOL local_materials)
         gGL.getTexUnit(detail_basecolor[i])->disable();
         gGL.getTexUnit(detail_basecolor[i])->activate();
 
-        gGL.getTexUnit(detail_normal[i])->unbind(LLTexUnit::TT_TEXTURE);
-        gGL.getTexUnit(detail_normal[i])->disable();
-        gGL.getTexUnit(detail_normal[i])->activate();
+        if (sPBRDetailMode >= TERRAIN_PBR_DETAIL_NORMAL)
+        {
+            gGL.getTexUnit(detail_normal[i])->unbind(LLTexUnit::TT_TEXTURE);
+            gGL.getTexUnit(detail_normal[i])->disable();
+            gGL.getTexUnit(detail_normal[i])->activate();
+        }
 
-        gGL.getTexUnit(detail_metalrough[i])->unbind(LLTexUnit::TT_TEXTURE);
-        gGL.getTexUnit(detail_metalrough[i])->disable();
-        gGL.getTexUnit(detail_metalrough[i])->activate();
+        if (sPBRDetailMode >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS)
+        {
+            gGL.getTexUnit(detail_metalrough[i])->unbind(LLTexUnit::TT_TEXTURE);
+            gGL.getTexUnit(detail_metalrough[i])->disable();
+            gGL.getTexUnit(detail_metalrough[i])->activate();
+        }
 
-        if (sPBRDetailMode >= PBR_DETAIL_EMISSIVE)
+        if (sPBRDetailMode >= TERRAIN_PBR_DETAIL_EMISSIVE)
         {
             gGL.getTexUnit(detail_emissive[i])->unbind(LLTexUnit::TT_TEXTURE);
             gGL.getTexUnit(detail_emissive[i])->disable();
diff --git a/indra/newview/llsettingsvo.cpp b/indra/newview/llsettingsvo.cpp
index deeecc6b3c..afae5f140b 100644
--- a/indra/newview/llsettingsvo.cpp
+++ b/indra/newview/llsettingsvo.cpp
@@ -718,11 +718,11 @@ void LLSettingsVOSky::applySpecial(void *ptarget, bool force)
     LLSettingsSky::ptr_t psky = LLEnvironment::instance().getCurrentSky();
 
     // TODO -- make these getters return vec3s
-    LLVector3 sunDiffuse = LLVector3(psky->getSunlightColor().mV);
-    LLVector3 moonDiffuse = LLVector3(psky->getMoonlightColor().mV);
+    LLVector3 sun_light_color = LLVector3(psky->getSunlightColor().mV);
+    LLVector3 moon_light_color = LLVector3(psky->getMoonlightColor().mV);
 
-    shader->uniform3fv(LLShaderMgr::SUNLIGHT_COLOR, sunDiffuse);
-    shader->uniform3fv(LLShaderMgr::MOONLIGHT_COLOR, moonDiffuse);
+    shader->uniform3fv(LLShaderMgr::SUNLIGHT_COLOR, sun_light_color);
+    shader->uniform3fv(LLShaderMgr::MOONLIGHT_COLOR, moon_light_color);
 
     shader->uniform3fv(LLShaderMgr::CLOUD_COLOR, LLVector3(psky->getCloudColor().mV));
 
@@ -765,9 +765,9 @@ void LLSettingsVOSky::applySpecial(void *ptarget, bool force)
             shader->uniform1f(LLShaderMgr::SKY_HDR_SCALE, auto_adjust_hdr_scale);
             LLColor3 blue_horizon = getBlueHorizon() * auto_adjust_blue_horizon_scale;
             LLColor3 blue_density = getBlueDensity() * auto_adjust_blue_density_scale;
-            LLColor3 sun_diffuse = getSunDiffuse() * auto_adjust_sun_color_scale;
+            sun_light_color = sun_light_color * auto_adjust_sun_color_scale;
             
-            shader->uniform3fv(LLShaderMgr::SUNLIGHT_COLOR, sun_diffuse.mV);
+            shader->uniform3fv(LLShaderMgr::SUNLIGHT_COLOR, sun_light_color.mV);
             shader->uniform3fv(LLShaderMgr::BLUE_DENSITY, blue_density.mV);
             shader->uniform3fv(LLShaderMgr::BLUE_HORIZON, blue_horizon.mV);
 
diff --git a/indra/newview/llviewerregion.cpp b/indra/newview/llviewerregion.cpp
index d541bb6647..ce57585d82 100755
--- a/indra/newview/llviewerregion.cpp
+++ b/indra/newview/llviewerregion.cpp
@@ -2438,7 +2438,19 @@ void LLViewerRegion::setSimulatorFeatures(const LLSD& sim_features)
 	mSimulatorFeatures = sim_features;
 
 	setSimulatorFeaturesReceived(true);
-	
+
+    // if region has MaxTextureResolution, set max_texture_dimension settings, otherwise use default
+    if (mSimulatorFeatures.has("MaxTextureResolution"))
+    {
+        S32 max_texture_resolution = mSimulatorFeatures["MaxTextureResolution"].asInteger();
+        gSavedSettings.setS32("max_texture_dimension_X", max_texture_resolution);
+        gSavedSettings.setS32("max_texture_dimension_Y", max_texture_resolution);
+    }
+    else
+    {
+        gSavedSettings.setS32("max_texture_dimension_X", 1024);
+        gSavedSettings.setS32("max_texture_dimension_Y", 1024);
+    }
 }
 
 //this is called when the parent is not cacheable.
diff --git a/indra/newview/llviewershadermgr.cpp b/indra/newview/llviewershadermgr.cpp
index e6cf37bc3c..b175172b9b 100644
--- a/indra/newview/llviewershadermgr.cpp
+++ b/indra/newview/llviewershadermgr.cpp
@@ -680,6 +680,7 @@ std::string LLViewerShaderMgr::loadBasicShaders()
         const F32 triplanar_factor = gSavedSettings.getF32("RenderTerrainPBRTriplanarBlendFactor");
         attribs["TERRAIN_TRIPLANAR_BLEND_FACTOR"] = llformat("%.2f", triplanar_factor);
         S32 detail = gSavedSettings.getS32("RenderTerrainPBRDetail");
+        detail = llclamp(detail, TERRAIN_PBR_DETAIL_MIN, TERRAIN_PBR_DETAIL_MAX);
         attribs["TERRAIN_PBR_DETAIL"] = llformat("%d", detail);
     }
 
diff --git a/indra/newview/llviewershadermgr.h b/indra/newview/llviewershadermgr.h
index 3530602776..57fc66ce0d 100644
--- a/indra/newview/llviewershadermgr.h
+++ b/indra/newview/llviewershadermgr.h
@@ -285,15 +285,19 @@ extern LLGLSLShader         gDeferredPBROpaqueProgram;
 extern LLGLSLShader         gDeferredPBRAlphaProgram;
 extern LLGLSLShader         gHUDPBRAlphaProgram;
 
-// Encodes detail level for dropping textures, in accordance with the GLTF spec
+// Encodes detail level for dropping textures, in accordance with the GLTF spec where possible
 // 0 is highest detail, -1 drops emissive, etc
+// Dropping metallic roughness is off-spec - Reserve for potato machines as needed
 // https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#additional-textures
 enum TerrainPBRDetail : S32
 {
-    TERRAIN_PBR_DETAIL_MAX            = 0,
-    TERRAIN_PBR_DETAIL_EMISSIVE       = 0,
-    TERRAIN_PBR_DETAIL_OCCLUSION      = -1,
-    TERRAIN_PBR_DETAIL_MIN            = -1,
+    TERRAIN_PBR_DETAIL_MAX                = 0,
+    TERRAIN_PBR_DETAIL_EMISSIVE           = 0,
+    TERRAIN_PBR_DETAIL_OCCLUSION          = -1,
+    TERRAIN_PBR_DETAIL_NORMAL             = -2,
+    TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS = -3,
+    TERRAIN_PBR_DETAIL_BASE_COLOR         = -4,
+    TERRAIN_PBR_DETAIL_MIN                = -4,
 };
 extern LLGLSLShader         gDeferredPBRTerrainProgram;
 #endif
diff --git a/indra/newview/llvlcomposition.cpp b/indra/newview/llvlcomposition.cpp
index f645023217..7c16ee4f61 100644
--- a/indra/newview/llvlcomposition.cpp
+++ b/indra/newview/llvlcomposition.cpp
@@ -142,6 +142,27 @@ BOOL LLTerrainMaterials::texturesReady(BOOL boost)
 
 BOOL LLTerrainMaterials::materialsReady(BOOL boost)
 {
+#if 1
+    static bool sRenderTerrainPBREnabled = gSavedSettings.get<bool>("RenderTerrainPBREnabled");
+    static LLCachedControl<bool> sRenderTerrainPBRForce(gSavedSettings, "RenderTerrainPBRForce", false);
+    if (sRenderTerrainPBREnabled && sRenderTerrainPBRForce)
+    {
+        bool defined = true;
+        for (S32 i = 0; i < ASSET_COUNT; i++)
+        {
+            if (!mDetailMaterials[i])
+            {
+                defined = false;
+                break;
+            }
+        }
+        if (defined)
+        {
+            return TRUE;
+        }
+    }
+#endif
+
     BOOL ready = TRUE;
 	for (S32 i = 0; i < ASSET_COUNT; i++)
 	{