SL-19838 Fix for transparent PBR materials always casting shadows.

2 files changed, 57 insertions, 1 deletions

diff --git a/indra/newview/app_settings/shaders/class1/deferred/pbrShadowAlphaBlendF.glsl b/indra/newview/app_settings/shaders/class1/deferred/pbrShadowAlphaBlendF.glsl
new file mode 100644
index 0000000000..79425ad716
--- /dev/null
+++ b/indra/newview/app_settings/shaders/class1/deferred/pbrShadowAlphaBlendF.glsl
@@ -0,0 +1,56 @@
+/** 
+ * @file pbrShadowAlphaBlendF.glsl
+ *
+ * $LicenseInfo:firstyear=2023&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2023, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+out vec4 frag_color;
+
+uniform sampler2D diffuseMap;
+
+in vec4 post_pos;
+in float target_pos_x;
+in vec4 vertex_color;
+in vec2 vary_texcoord0;
+uniform float minimum_alpha;
+
+void main() 
+{
+    float alpha = texture(diffuseMap,vary_texcoord0.xy).a;
+
+    alpha *= vertex_color.a;
+
+    if (alpha < 0.05) // treat as totally transparent
+    {
+        discard;
+    }
+
+    if (alpha < 0.88) // treat as semi-transparent
+    {
+        if (fract(0.5*floor(target_pos_x / post_pos.w )) < 0.25)
+        {
+            discard;
+        }
+    }
+
+	frag_color = vec4(1,1,1,1);
+}
diff --git a/indra/newview/app_settings/shaders/class1/deferred/pbrShadowAlphaMaskF.glsl b/indra/newview/app_settings/shaders/class1/deferred/pbrShadowAlphaMaskF.glsl
index e06f3a5f44..1d1545be7e 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/pbrShadowAlphaMaskF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/pbrShadowAlphaMaskF.glsl
@@ -35,7 +35,7 @@ uniform float minimum_alpha;
 
 void main() 
 {
-    float alpha = diffuseLookup(vary_texcoord0.xy).a;
+    float alpha = texture(diffuseMap,vary_texcoord0.xy).a;
 
     if (alpha < minimum_alpha)
     {