Traktor: Write to velocity buffer in Ocean shader.

code/Terrain/OceanComponent.cpp

@@ -27,6 +27,7 @@
 #include "Terrain/TerrainComponent.h"
 #include "World/Entity.h"
 #include "World/IWorldRenderPass.h"
+#include "World/WorldHandles.h"
 #include "World/WorldRenderView.h"
 #include "World/WorldSetupContext.h"
 
@@ -40,6 +41,7 @@ const render::Handle s_handleTerrain_WorldOrigin(L"Terrain_WorldOrigin");
 const render::Handle s_handleTerrain_WorldExtent(L"Terrain_WorldExtent");
 const render::Handle s_handleOcean_HaveTerrain(L"Ocean_HaveTerrain");
 const render::Handle s_handleOcean_Eye(L"Ocean_Eye");
+const render::Handle s_handleOcean_LastEye(L"Ocean_LastEye");
 const render::Handle s_handleOcean_ShallowTint(L"Ocean_ShallowTint");
 const render::Handle s_handleOcean_DeepColor(L"Ocean_DeepColor");
 const render::Handle s_handleOcean_Opacity(L"Ocean_Opacity");
@@ -85,6 +87,8 @@ bool OceanComponent::create(resource::IResourceManager* resourceManager, render:
 	m_spectrumTexture = renderSystem->createSimpleTexture(stcd, T_FILE_LINE_W);
 	m_evolvedSpectrumTextures[0] = renderSystem->createSimpleTexture(stcd, T_FILE_LINE_W);
 	m_evolvedSpectrumTextures[1] = renderSystem->createSimpleTexture(stcd, T_FILE_LINE_W);
+	m_evolvedSpectrumTextures[2] = renderSystem->createSimpleTexture(stcd, T_FILE_LINE_W);
+	m_evolvedSpectrumTextures[3] = renderSystem->createSimpleTexture(stcd, T_FILE_LINE_W);
 	m_foamTexture = renderSystem->createSimpleTexture(stcd, T_FILE_LINE_W);
 
 	AlignedVector< render::VertexElement > vertexElements;
@@ -176,6 +180,8 @@ void OceanComponent::destroy()
 	safeDestroy(m_spectrumTexture);
 	safeDestroy(m_evolvedSpectrumTextures[0]);
 	safeDestroy(m_evolvedSpectrumTextures[1]);
+	safeDestroy(m_evolvedSpectrumTextures[2]);
+	safeDestroy(m_evolvedSpectrumTextures[3]);
 	safeDestroy(m_foamTexture);
 	m_shader.clear();
 }
@@ -266,6 +272,12 @@ void OceanComponent::setup(
 		m_spectrumDirty = false;
 	}
 
+	// Swap textures so we have last and current.
+	{
+		std::swap(m_evolvedSpectrumTextures[0], m_evolvedSpectrumTextures[2]);
+		std::swap(m_evolvedSpectrumTextures[1], m_evolvedSpectrumTextures[3]);
+	}
+
 	// Evolve spectrum over time.
 	{
 		Ref< render::RenderPass > rp = new render::RenderPass(L"Ocean compute spectrum evolve");
@@ -388,6 +400,7 @@ void OceanComponent::build(
 	if (!m_owner || worldRenderView.getSnapshot())
 		return;
 
+	const bool writeVelocity = (worldRenderPass.getTechnique() == world::s_techniqueVelocityWrite);
 	bool haveTerrain = false;
 
 	// Get terrain from owner.
@@ -399,9 +412,8 @@ void OceanComponent::build(
 	}
 
 	const Transform transform = m_owner->getTransform() * Transform(Vector4(0.0f, m_elevation, 0.0f, 0.0f));
-	const Matrix44& view = worldRenderView.getView();
-	const Matrix44 viewInv = view.inverse();
-	const Vector4 eye = viewInv.translation().xyz1();
+	const Vector4 lastEye = worldRenderView.getLastView().inverse().translation().xyz1();
+	const Vector4 eye = worldRenderView.getView().inverse().translation().xyz1();
 
 	// Render ocean geometry.
 	auto perm = worldRenderPass.getPermutation(m_shader);
@@ -423,11 +435,23 @@ void OceanComponent::build(
 	renderBlock->programParams->beginParameters(renderContext);
 	renderBlock->programParams->setFloatParameter(s_handleOcean_Opacity, m_opacity);
 	renderBlock->programParams->setVectorParameter(s_handleOcean_Eye, eye);
+	renderBlock->programParams->setVectorParameter(s_handleOcean_LastEye, lastEye);
 	renderBlock->programParams->setVectorParameter(s_handleOcean_ShallowTint, m_shallowTint);
 	renderBlock->programParams->setVectorParameter(s_handleOcean_DeepColor, m_deepColor);
-	renderBlock->programParams->setTextureParameter(s_handleOcean_WaveTexture0, m_evolvedSpectrumTextures[0]);
-	renderBlock->programParams->setTextureParameter(s_handleOcean_WaveTexture1, m_evolvedSpectrumTextures[1]);
-	renderBlock->programParams->setTextureParameter(s_handleOcean_WaveTexture2, m_foamTexture);
+
+	if (!writeVelocity)
+	{
+		renderBlock->programParams->setTextureParameter(s_handleOcean_WaveTexture0, m_evolvedSpectrumTextures[0]);
+		renderBlock->programParams->setTextureParameter(s_handleOcean_WaveTexture1, m_evolvedSpectrumTextures[1]);
+		renderBlock->programParams->setTextureParameter(s_handleOcean_WaveTexture2, m_foamTexture);
+	}
+	else
+	{
+		renderBlock->programParams->setTextureParameter(s_handleOcean_WaveTexture0, m_evolvedSpectrumTextures[0]);
+		renderBlock->programParams->setTextureParameter(s_handleOcean_WaveTexture1, m_evolvedSpectrumTextures[1]);
+		renderBlock->programParams->setTextureParameter(s_handleOcean_WaveTexture2, m_evolvedSpectrumTextures[2]);
+		renderBlock->programParams->setTextureParameter(s_handleOcean_WaveTexture3, m_evolvedSpectrumTextures[3]);
+	}
 
 	if (haveTerrain)
 	{

code/Terrain/OceanComponent.h

@@ -110,7 +110,7 @@ class T_DLLCLASS OceanComponent : public world::IEntityComponent
 	resource::Proxy< render::Shader > m_shaderWave;	//!< Compute shader to generate wave maps.
 	resource::Proxy< render::Shader > m_shader;
 	Ref< render::ITexture > m_spectrumTexture;
-	Ref< render::ITexture > m_evolvedSpectrumTextures[2];
+	Ref< render::ITexture > m_evolvedSpectrumTextures[4];
 	Ref< render::ITexture > m_foamTexture;
 	Ref< const render::IVertexLayout > m_vertexLayout;
 	Ref< render::Buffer > m_indexBuffer;

code/World/Shared/WorldRenderPassShared.cpp

@@ -87,6 +87,7 @@ void WorldRenderPassShared::setWorldProgramParameters(render::ProgramParameters*
 	{
 		const Matrix44 w0 = lastWorld.toMatrix44();
 		programParams->setMatrixParameter(s_handleLastWorld, w0);
+		programParams->setMatrixParameter(s_handleLastView, m_worldRenderView.getLastView());
 		programParams->setMatrixParameter(s_handleLastWorldView, m_worldRenderView.getLastView() * w0);
 	}
 }

code/World/WorldHandles.cpp

@@ -38,6 +38,7 @@ const render::Handle s_handleFogDistanceAndDensity(L"World_FogDistanceAndDensity
 const render::Handle s_handleGamma(L"World_Gamma");
 const render::Handle s_handleGammaInverse(L"World_GammaInverse");
 const render::Handle s_handleLastWorld(L"World_LastWorld");
+const render::Handle s_handleLastView(L"World_LastView");
 const render::Handle s_handleLastWorldView(L"World_LastWorldView");
 const render::Handle s_handleLightDiffuseMap(L"World_LightDiffuseMap");
 const render::Handle s_handleLightIndexSBuffer(L"World_LightIndexSBuffer");

code/World/WorldHandles.h

@@ -48,6 +48,7 @@ extern const render::Handle T_DLLCLASS s_handleFogDistanceAndDensity;
 extern const render::Handle T_DLLCLASS s_handleGamma;
 extern const render::Handle T_DLLCLASS s_handleGammaInverse;
 extern const render::Handle T_DLLCLASS s_handleLastWorld;
+extern const render::Handle T_DLLCLASS s_handleLastView;
 extern const render::Handle T_DLLCLASS s_handleLastWorldView;
 extern const render::Handle T_DLLCLASS s_handleLightDiffuseMap;
 extern const render::Handle T_DLLCLASS s_handleLightIndexSBuffer;