Fix singlepass lighting artifacts and make it the default (#2652)

* prefer singlepass lighting

* keep old tests by defaulting to multipass lighting

* make sure TBN is always normalized

* update tests

* fix sp lighting when no light is in the scene

* apply Gram-Schmidt orthogonalization do SPLighting

* update tests

Author: riccardobl

jme3-core/src/main/java/com/jme3/renderer/RenderManager.java

@@ -123,7 +123,7 @@ public class RenderManager {
     private boolean handleTranslucentBucket = true;
     private AppProfiler prof;
     private LightFilter lightFilter = new DefaultLightFilter();
-    private TechniqueDef.LightMode preferredLightMode = TechniqueDef.LightMode.MultiPass;
+    private TechniqueDef.LightMode preferredLightMode = TechniqueDef.LightMode.SinglePass;
     private int singlePassLightBatchSize = 1;
     private int maxSinglePassLightBatchSize = 16;
     private final MatParamOverride boundDrawBufferId = new MatParamOverride(VarType.Int, "BoundDrawBuffer", 0);

jme3-core/src/main/resources/Common/MatDefs/Light/GBuf.vert

@@ -35,16 +35,17 @@ void main(){
    gl_Position = g_WorldViewProjectionMatrix * pos;
    texCoord = inTexCoord;
 
-   #if defined(NORMALMAP)
-     vec4 wvNormal, wvTangent, wvBinormal;
+   #if defined(NORMALMAP)
+     vec4 wvNormal, wvTangent, wvBinormal;
 
      wvNormal   = vec4(inNormal, 0.0);
      wvTangent  = vec4(inTangent, 0.0);
 
-     wvNormal.xyz   = normalize( (g_WorldMatrix * wvNormal).xyz   );
-     wvTangent.xyz  = normalize( (g_WorldMatrix * wvTangent).xyz  );
-     wvBinormal.xyz = cross(wvNormal.xyz, wvTangent.xyz);
-     tbnMat = mat3(wvTangent.xyz, wvBinormal.xyz, wvNormal.xyz);
+     wvNormal.xyz   = normalize( (g_WorldMatrix * wvNormal).xyz   );
+     wvTangent.xyz  = normalize( (g_WorldMatrix * wvTangent).xyz  );
+     wvTangent.xyz  = normalize(wvTangent.xyz - wvNormal.xyz * dot(wvTangent.xyz, wvNormal.xyz));
+     wvBinormal.xyz = normalize(cross(wvNormal.xyz, wvTangent.xyz));
+     tbnMat = mat3(wvTangent.xyz, wvBinormal.xyz, wvNormal.xyz);
 
      vNormal = wvNormal.xyz;
    #else

jme3-core/src/main/resources/Common/MatDefs/Light/Lighting.vert

@@ -127,11 +127,13 @@ void main(){
    wvLightPos.w = g_LightPosition.w;
    vec4 lightColor = g_LightColor;
 
-   #if (defined(NORMALMAP) || defined(PARALLAXMAP)) && !defined(VERTEX_LIGHTING)
-     vec3 wvTangent = normalize(TransformNormal(modelSpaceTan));
-     vec3 wvBinormal = cross(wvNormal, wvTangent);
-     mat3 tbnMat = mat3(wvTangent, wvBinormal * inTangent.w,wvNormal);
-   #endif
+   #if (defined(NORMALMAP) || defined(PARALLAXMAP)) && !defined(VERTEX_LIGHTING)
+     vec3 tbnNormal = normalize(wvNormal);
+     vec3 wvTangent = normalize(TransformNormal(modelSpaceTan));
+     wvTangent = normalize(wvTangent - tbnNormal * dot(wvTangent, tbnNormal));
+     vec3 wvBinormal = normalize(cross(tbnNormal, wvTangent)) * inTangent.w;
+     mat3 tbnMat = mat3(wvTangent, wvBinormal, tbnNormal);
+   #endif
 
    #if defined(NORMALMAP) && !defined(VERTEX_LIGHTING)
      vViewDir  = -wvPosition * tbnMat;    

jme3-core/src/main/resources/Common/MatDefs/Light/SPLighting.frag

@@ -95,7 +95,10 @@ uniform float m_Shininess;
 void main(){
     #if !defined(VERTEX_LIGHTING)
         #if defined(NORMALMAP)
-             mat3 tbnMat = mat3(vTangent.xyz, vTangent.w * cross( (vNormal), (vTangent.xyz)), vNormal.xyz);
+            vec3 tbnNormal = normalize(vNormal.xyz);
+            vec3 tbnTangent = normalize(vTangent.xyz - tbnNormal * dot(vTangent.xyz, tbnNormal));
+            vec3 tbnBinormal = normalize(cross(tbnNormal, tbnTangent)) * vTangent.w;
+            mat3 tbnMat = mat3(tbnTangent, tbnBinormal, tbnNormal);
 
             if (!gl_FrontFacing)
             {

jme3-core/src/main/resources/Common/ShaderLib/Lighting.glsllib

@@ -11,6 +11,10 @@ void lightComputeDir(in vec3 worldPos, in float lightType, in vec4 position, out
     vec3 tempVec = position.xyz * sign(posLight - 0.5) - (worldPos * posLight);
     lightVec = tempVec;          
     float dist = length(tempVec);
+    if (dist <= 0.0) {
+        lightDir = vec4(0.0);
+        return;
+    }
 #ifdef SRGB
     lightDir.w = (1.0 - position.w * dist) / (1.0 + position.w * dist * dist);
     lightDir.w = clamp(lightDir.w, 1.0 - posLight, 1.0);

jme3-core/src/main/resources/Common/ShaderLib/Math.glsllib

@@ -1,17 +1,22 @@
-#ifndef __MATH_GLSLLIB__
-#define __MATH_GLSLLIB__
-
-/// Multiplies the vector by the quaternion, then returns the resultant vector.
-vec3 Math_QuaternionMult(in vec4 quat, in vec3 vec){
-	return vec + 2.0 * cross(quat.xyz, cross(quat.xyz, vec) + quat.w * vec);
-}
-
-void Math_lengthAndNormalize(in vec3 vec,out float outLength,out vec3 outNormal){
-    float dotv=dot(vec,vec);
-    float invl=inversesqrt(dotv);
-    outNormal=vec*invl;
-    outLength=invl*dotv;
-}
-
-
+#ifndef __MATH_GLSLLIB__
+#define __MATH_GLSLLIB__
+
+/// Multiplies the vector by the quaternion, then returns the resultant vector.
+vec3 Math_QuaternionMult(in vec4 quat, in vec3 vec){
+	return vec + 2.0 * cross(quat.xyz, cross(quat.xyz, vec) + quat.w * vec);
+}
+
+void Math_lengthAndNormalize(in vec3 vec,out float outLength,out vec3 outNormal){
+    float dotv=dot(vec,vec);
+    if(dotv <= 0.0){
+        outNormal = vec3(0.0);
+        outLength = 0.0;
+        return;
+    }
+    float invl=inversesqrt(dotv);
+    outNormal=vec*invl;
+    outLength=invl*dotv;
+}
+
+
 #endif

jme3-core/src/main/resources/Common/ShaderLib/Tangent.glsllib

@@ -5,7 +5,9 @@ void Tangent_ComputeVS(out vec3 outNormal, out vec3 outTangent){
     outTangent = normalize(g_NormalMatrix * inTangent);
 }
 
-mat3 Tangent_GetBasis(){
-    vec3 wvBinormal = cross(wvNormal, wvTangent);
-    return mat3(wvTangent, wvBinormal, wvNormal);
-}
+mat3 Tangent_GetBasis(){
+    vec3 n = normalize(wvNormal);
+    vec3 t = normalize(wvTangent - n * dot(wvTangent, n));
+    vec3 b = normalize(cross(n, t));
+    return mat3(t, b, n);
+}

jme3-core/src/main/resources/Common/ShaderLib/module/pbrlighting/PBRLightingUtils.glsllib

@@ -305,8 +305,10 @@
             surface.envLightContribution = vec3(0.0);
 
             #ifdef ENABLE_PBRLightingUtils_getWorldTangent
-                vec3 tan = normalize(wTangent.xyz); 
-                surface.tbnMat = mat3(tan, wTangent.w * cross( surface.geometryNormal, tan), surface.geometryNormal);
+                vec3 n = normalize(surface.geometryNormal);
+                vec3 tan = normalize(wTangent.xyz - n * dot(wTangent.xyz, n));
+                vec3 bitan = normalize(cross(n, tan)) * wTangent.w;
+                surface.tbnMat = mat3(tan, bitan, n);
                 surface.hasTangents = true;
             #endif
 

jme3-core/src/test/java/com/jme3/system/TestUtil.java

@@ -34,6 +34,7 @@
 import com.jme3.asset.AssetConfig;
 import com.jme3.asset.AssetManager;
 import com.jme3.asset.DesktopAssetManager;
+import com.jme3.material.TechniqueDef;
 import com.jme3.renderer.RenderManager;
 import com.jme3.renderer.Renderer;
 
@@ -63,6 +64,7 @@ public static RenderManager createRenderManager() {
 
     public static RenderManager createRenderManager(Renderer renderer) {
         RenderManager rm = new RenderManager(renderer);
+        rm.setPreferredLightMode(TechniqueDef.LightMode.MultiPass);
         rm.setPassDrawBufferTargetIdToShaders(false);
         return rm;
     }