#219: Port the error correction terms from the TDM shaders.

Don't cull out-of-view objects for shadow-casting lights
codereader · Mar 25, 2022 · e51121e · e51121e
1 parent 4dcebf6
commit e51121e
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Showing 4 changed files with 33 additions and 17 deletions.
diff --git a/install/gl/interaction_fp.glsl b/install/gl/interaction_fp.glsl
@@ -7,12 +7,13 @@ uniform sampler2D	u_attenuationmap_xy;
 uniform sampler2D	u_attenuationmap_z;
 uniform sampler2D	u_ShadowMap;
 
-uniform vec3		u_view_origin;
-uniform vec3		u_light_origin;
-uniform vec3		u_light_color;
-uniform float		u_light_scale;
-uniform vec4		u_ColourModulation;
-uniform vec4		u_ColourAddition;
+uniform vec3    u_view_origin;
+uniform vec3    u_light_origin;
+uniform vec3    u_light_color;
+uniform float   u_light_scale;
+uniform vec4    u_ColourModulation;
+uniform vec4    u_ColourAddition;
+uniform mat4    u_ObjectTransform;     // object to world
 
 // Defines the region within the shadow map atlas containing the depth information of the current light
 uniform vec4        u_ShadowMapRect; // x,y,w,h
@@ -153,9 +154,13 @@ void main()
         float maxAbsL = max(absL.x, max(absL.y, absL.z));
         float centerFragZ = maxAbsL;
 
+        vec3 normal = mat3(u_ObjectTransform) * N;
+
+        float lightFallAngle = -dot(normal, L);
+        float errorMargin = 5.0 * maxAbsL / ( shadowMapResolution * max(lightFallAngle, 0.1) );
+
         float centerBlockerZ = getDepthValueForVector(u_ShadowMap, u_ShadowMapRect, L);
-        float lit = float(centerBlockerZ >= centerFragZ/* - errorMargin*/);
-        //lit = var_WorldLightDirection.y > 0.2 ? 1 : 0;
+        float lit = float(centerBlockerZ >= centerFragZ - errorMargin);
 
         totalColor *= lit;
     }

diff --git a/radiantcore/rendersystem/backend/LightInteractions.cpp b/radiantcore/rendersystem/backend/LightInteractions.cpp
@@ -33,6 +33,8 @@ bool LightInteractions::castsShadows()
 
 void LightInteractions::collectSurfaces(const IRenderView& view, const std::set<IRenderEntityPtr>& entities)
 {
+    bool shadowCasting = castsShadows();
+
     // Now check all the entities intersecting with this light
     for (const auto& entity : entities)
     {
@@ -45,17 +47,21 @@ void LightInteractions::collectSurfaces(const IRenderView& view, const std::set<
             // Don't collect invisible shaders
             if (!shader->isVisible()) return;
 
-            if (object->isOriented())
+            // For non-shadow lights we can cull surfaces that are not in view
+            if (!shadowCasting)
             {
-                if (view.TestAABB(object->getObjectBounds(), object->getObjectTransform()) == VOLUME_OUTSIDE)
+                if (object->isOriented())
+                {
+                    if (view.TestAABB(object->getObjectBounds(), object->getObjectTransform()) == VOLUME_OUTSIDE)
+                    {
+                        return;
+                    }
+                }
+                else if (view.TestAABB(object->getObjectBounds()) == VOLUME_OUTSIDE) // non-oriented AABB test
                 {
                     return;
                 }
             }
-            else if (view.TestAABB(object->getObjectBounds()) == VOLUME_OUTSIDE) // non-oriented AABB test
-            {
-                return;
-            }
 
             auto glShader = static_cast<OpenGLShader*>(shader);
 
@@ -76,7 +82,7 @@ void LightInteractions::collectSurfaces(const IRenderView& view, const std::set<
 }
 
 void LightInteractions::fillDepthBuffer(OpenGLState& state, GLSLDepthFillAlphaProgram& program, 
-    const IRenderView& view, std::size_t renderTime, std::vector<IGeometryStore::Slot>& untransformedObjectsWithoutAlphaTest)
+    std::size_t renderTime, std::vector<IGeometryStore::Slot>& untransformedObjectsWithoutAlphaTest)
 {
     std::vector<IGeometryStore::Slot> untransformedObjects;
     untransformedObjects.reserve(1000);

diff --git a/radiantcore/rendersystem/backend/LightInteractions.h b/radiantcore/rendersystem/backend/LightInteractions.h
@@ -91,7 +91,7 @@ class LightInteractions
     void collectSurfaces(const IRenderView& view, const std::set<IRenderEntityPtr>& entities);
 
     void fillDepthBuffer(OpenGLState& state, GLSLDepthFillAlphaProgram& program, 
-        const IRenderView& view, std::size_t renderTime, std::vector<IGeometryStore::Slot>& untransformedObjectsWithoutAlphaTest);
+        std::size_t renderTime, std::vector<IGeometryStore::Slot>& untransformedObjectsWithoutAlphaTest);
 
     void drawShadowMap(OpenGLState& state, const Rectangle& rectangle, ShadowMapProgram& program);
 

diff --git a/radiantcore/rendersystem/backend/LightingModeRenderer.cpp b/radiantcore/rendersystem/backend/LightingModeRenderer.cpp
@@ -105,6 +105,9 @@ IRenderResult::Ptr LightingModeRenderer::render(RenderStateFlags globalFlagsMask
     glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
     current.setRenderFlag(RENDER_FILL);
 
+    glPolygonOffset(0, 0);
+    glEnable(GL_POLYGON_OFFSET_FILL);
+
     // Enable the 4 clip planes, they are used in the vertex shader
     glEnable(GL_CLIP_DISTANCE0);
     glEnable(GL_CLIP_DISTANCE1);
@@ -129,6 +132,8 @@ IRenderResult::Ptr LightingModeRenderer::render(RenderStateFlags globalFlagsMask
     glDisable(GL_CLIP_DISTANCE1);
     glDisable(GL_CLIP_DISTANCE0);
 
+    glDisable(GL_POLYGON_OFFSET_FILL);
+
     // Restore view port
     glViewport(previousViewport[0], previousViewport[1], previousViewport[2], previousViewport[3]);
 
@@ -202,7 +207,7 @@ std::size_t LightingModeRenderer::drawDepthFillPass(OpenGLState& current, Render
 
     for (auto& interactionList : interactionLists)
     {
-        interactionList.fillDepthBuffer(current, *depthFillProgram, view, renderTime, _untransformedObjectsWithoutAlphaTest);
+        interactionList.fillDepthBuffer(current, *depthFillProgram, renderTime, _untransformedObjectsWithoutAlphaTest);
         drawCalls += interactionList.getDepthDrawCalls();
     }