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diff --git a/doc/testplans/pbr_terrain_appearance.md b/doc/testplans/pbr_terrain_appearance.md
index 11b501be3a..eab5b8bf44 100644
--- a/doc/testplans/pbr_terrain_appearance.md
+++ b/doc/testplans/pbr_terrain_appearance.md
@@ -39,7 +39,7 @@ PBR terrain does not support materials with alpha blend or double-sided. In addi
## PBR Terrain Texture Transforms
-Like PBR materials on prims, PBR terrain repeats are based on the [KHR\_texture\_transform](https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_texture_transform) spec, and thus should be expected to behave the same way.
+Like PBR materials on prims, PBR terrain repeats are based on the [KHR\_texture\_transform](https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_texture_transform) spec, and thus should be expected to behave the same way. We currently suport offset, rotation, and scale from the spec. texCoord is not currently supported.
The southwest corner of a region, at z=0, is the UV origin for all texture coordinates of the whole region. Unless an offset is also applied, scale and rotation of the terrain texture transforms are relative to that point.
@@ -50,3 +50,14 @@ If triplanar mapping is enabled, and an avatar faces an axially-aligned wall, th
Textures of materials should not appear mirrored.
When triplanar mapping is enabled, rotations on the axially aligned walls should apply in the same direction as they would on flat ground.
+
+## PBR Terrain Normal Textures
+
+This section assumes terrain normal maps are enabled at the current graphics setting.
+
+PBR terrain should have approximately correct lighting based on the normal texture:
+
+- When on flat ground
+- On cliffs, when triplanar mapping is enabled. Lighting will be somewhat less accurate when the cliff face is not axially aligned.
+- If no Terrain Texture Transform is applied.
+- If a Terrain Texture Transform is applied, especially for rotation or negative scale.