Fix the coordinate frame for eyeDir, minor cleanup (Bug #3440)

files/shaders/objects_fragment.glsl

@@ -71,23 +71,24 @@ void main()
     vec3 normalizedNormal = normalize(passNormal);
     vec3 normalizedTangent = normalize(passTangent);
     vec3 binormal = cross(normalizedTangent, normalizedNormal);
-    mat3 tbn = mat3(normalizedTangent, binormal, normalizedNormal);
+    mat3 tbnTranspose = mat3(normalizedTangent, binormal, normalizedNormal);
 
-    vec3 viewNormal = gl_NormalMatrix * normalize(tbn * (normalTex.xyz * 2.0 - 1.0));
+    vec3 viewNormal = gl_NormalMatrix * normalize(tbnTranspose * (normalTex.xyz * 2.0 - 1.0));
 #else
     vec3 viewNormal = gl_NormalMatrix * normalize(passNormal);
 #endif
 
 #if @parallax
-    vec3 cameraPos = osg_ViewMatrixInverse[3].xyz;
-    vec3 eyeDir = normalize(cameraPos - (osg_ViewMatrixInverse * vec4(passViewPos, 1)).xyz);
-    vec2 offset = getParallaxOffset(eyeDir, tbn, normalTex.a);
+    vec3 cameraPos = (gl_ModelViewMatrixInverse * vec4(0,0,0,1)).xyz;
+    vec3 objectPos = (gl_ModelViewMatrixInverse * vec4(passViewPos, 1)).xyz;
+    vec3 eyeDir = normalize(cameraPos - objectPos);
+    vec2 offset = getParallaxOffset(eyeDir, tbnTranspose, normalTex.a);
     adjustedDiffuseUV += offset; // only offset diffuse for now, other textures are more likely to be using a completely different UV set
 
 #if @diffuseMapUV == @normalMapUV
     // fetch a new normal using updated coordinates
     normalTex = texture2D(normalMap, adjustedDiffuseUV);
-    viewNormal = gl_NormalMatrix * normalize(tbn * (normalTex.xyz * 2.0 - 1.0));
+    viewNormal = gl_NormalMatrix * normalize(tbnTranspose * (normalTex.xyz * 2.0 - 1.0));
 #endif
 
 #endif

files/shaders/terrain_fragment.glsl

@@ -42,21 +42,22 @@ void main()
     vec3 tangent = vec3(1.0, 0.0, 0.0);
     vec3 binormal = normalize(cross(tangent, normalizedNormal));
     tangent = normalize(cross(normalizedNormal, binormal)); // note, now we need to re-cross to derive tangent again because it wasn't orthonormal
-    mat3 tbn = mat3(tangent, binormal, normalizedNormal);
+    mat3 tbnTranspose = mat3(tangent, binormal, normalizedNormal);
 
-    vec3 viewNormal = normalize(gl_NormalMatrix * (tbn * (normalTex.xyz * 2.0 - 1.0)));
+    vec3 viewNormal = normalize(gl_NormalMatrix * (tbnTranspose * (normalTex.xyz * 2.0 - 1.0)));
 #else
     vec3 viewNormal = normalize(gl_NormalMatrix * passNormal);
 #endif
 
 #if @parallax
-    vec3 cameraPos = osg_ViewMatrixInverse[3].xyz;
-    vec3 eyeDir = normalize(cameraPos - (osg_ViewMatrixInverse * vec4(passViewPos, 1)).xyz);
-    adjustedUV += getParallaxOffset(eyeDir, tbn, normalTex.a);
+    vec3 cameraPos = (gl_ModelViewMatrixInverse * vec4(0,0,0,1)).xyz;
+    vec3 objectPos = (gl_ModelViewMatrixInverse * vec4(passViewPos, 1)).xyz;
+    vec3 eyeDir = normalize(cameraPos - objectPos);
+    adjustedUV += getParallaxOffset(eyeDir, tbnTranspose, normalTex.a);
 
     // update normal using new coordinates
     normalTex = texture2D(normalMap, adjustedUV);
-    viewNormal = normalize(gl_NormalMatrix * (tbn * (normalTex.xyz * 2.0 - 1.0)));
+    viewNormal = normalize(gl_NormalMatrix * (tbnTranspose * (normalTex.xyz * 2.0 - 1.0)));
 #endif
 
     vec4 diffuseTex = texture2D(diffuseMap, adjustedUV);