- Fix shadow rendering (fix light camera setting mistake)

NEDJIMAbelgacem · nyalldawson · commit 15d48a141804 · 2022-02-01T09:51:27.000+10:00
- Add depth and shadow texture coordinates checking
- Improve performance by selecting front faces for forward pass and back faces for shadow pass
diff --git a/src/3d/qgsshadowrenderingframegraph.cpp b/src/3d/qgsshadowrenderingframegraph.cpp
@@ -90,7 +90,17 @@ Qt3DRender::QFrameGraphNode *QgsShadowRenderingFrameGraph::constructForwardRende
   mForwardClearBuffers->setBuffers( Qt3DRender::QClearBuffers::ColorDepthBuffer );
   mForwardClearBuffers->setClearDepthValue( 1.0f );
 
-  mFrustumCulling = new Qt3DRender::QFrustumCulling( mForwardClearBuffers );
+  Qt3DRender::QRenderStateSet *forwaredRenderStateSet = new Qt3DRender::QRenderStateSet( mForwardClearBuffers );
+
+  Qt3DRender::QDepthTest *depthTest = new Qt3DRender::QDepthTest;
+  depthTest->setDepthFunction( Qt3DRender::QDepthTest::Less );
+  forwaredRenderStateSet->addRenderState( depthTest );
+
+  Qt3DRender::QCullFace *cullFace = new Qt3DRender::QCullFace;
+  cullFace->setMode( Qt3DRender::QCullFace::CullingMode::Back );
+  forwaredRenderStateSet->addRenderState( cullFace );
+
+  mFrustumCulling = new Qt3DRender::QFrustumCulling( forwaredRenderStateSet );
 
   return mMainCameraSelector;
 }
@@ -133,7 +143,7 @@ Qt3DRender::QFrameGraphNode *QgsShadowRenderingFrameGraph::constructShadowRender
   mShadowRenderStateSet->addRenderState( shadowDepthTest );
 
   Qt3DRender::QCullFace *shadowCullFace = new Qt3DRender::QCullFace;
-  shadowCullFace->setMode( Qt3DRender::QCullFace::NoCulling );
+  shadowCullFace->setMode( Qt3DRender::QCullFace::CullingMode::Front );
   mShadowRenderStateSet->addRenderState( shadowCullFace );
 
   return mLightCameraSelectorShadowPass;
@@ -142,7 +152,7 @@ Qt3DRender::QFrameGraphNode *QgsShadowRenderingFrameGraph::constructShadowRender
 Qt3DRender::QFrameGraphNode *QgsShadowRenderingFrameGraph::constructPostprocessingPass()
 {
   mPostProcessingCameraSelector = new Qt3DRender::QCameraSelector;
-  mPostProcessingCameraSelector->setCamera( mMainCamera );
+  mPostProcessingCameraSelector->setCamera( mLightCamera );
 
   mPostprocessPassLayerFilter = new Qt3DRender::QLayerFilter( mPostProcessingCameraSelector );
   mPostprocessPassLayerFilter->addLayer( mPostprocessPassLayer );
@@ -419,7 +429,11 @@ void calculateViewExtent( Qt3DRender::QCamera *camera, float shadowRenderingDist
     QVector3D( 0.0f,  0.0f, depth ),
     QVector3D( 0.0f,  1.0f, depth ),
     QVector3D( 1.0f,  0.0f, depth ),
-    QVector3D( 1.0f,  1.0f, depth )
+    QVector3D( 1.0f,  1.0f, depth ),
+    QVector3D( 0.0f,  0.0f, 0 ),
+    QVector3D( 0.0f,  1.0f, 0 ),
+    QVector3D( 1.0f,  0.0f, 0 ),
+    QVector3D( 1.0f,  1.0f, 0 )
   };
   maxX = std::numeric_limits<float>::lowest();
   maxY = std::numeric_limits<float>::lowest();
diff --git a/src/3d/shaders/postprocess.frag b/src/3d/shaders/postprocess.frag
@@ -66,6 +66,9 @@ float CalcShadowFactor(vec4 LightSpacePos)
   UVCoords.y = 0.5 * ProjCoords.y + 0.5;
   float z = 0.5 * ProjCoords.z + 0.5;
 
+  if ( UVCoords.x < 0 || UVCoords.x > 1 || UVCoords.y < 0 || UVCoords.y > 1 )
+   return 1.0;
+
   // percentage close filtering of the shadow map
   float shadow = 0.0;
   int k = 1;
@@ -109,14 +112,17 @@ float edlFactor(vec2 coords)
 
 void main()
 {
-  vec3 worldPosition = WorldPosFromDepth(texture(depthTexture, texCoord).r);
+  float depth = texture(depthTexture, texCoord).r;
+  vec3 worldPosition = WorldPosFromDepth( depth );
   vec4 positionInLightSpace = projectionMatrix * viewMatrix * vec4(worldPosition, 1.0f);
   positionInLightSpace /= positionInLightSpace.w;
   vec3 color = texture(colorTexture, texCoord).rgb;
   // if shadow rendering is disabled or the pixel is outside the shadow rendering distance don't render shadows
-  if (renderShadows == 0 || worldPosition.x > shadowMaxX || worldPosition.x < shadowMinX || worldPosition.z > shadowMaxZ || worldPosition.z < shadowMinZ) {
-    fragColor = vec4(color.rgb, 1.0f);
-  } else {
+  if (renderShadows == 0 || depth >= 1 || worldPosition.x > shadowMaxX || worldPosition.x < shadowMinX || worldPosition.z > shadowMaxZ || worldPosition.z < shadowMinZ)
+  {
+    fragColor = vec4(color, 1.0f);
+  } else
+  {
     float visibilityFactor = CalcShadowFactor(positionInLightSpace);
     fragColor = vec4(visibilityFactor * color, 1.0f);
   }
