Merge pull request #4421 from aws-lumberyard-dev/Atom/dmcdiar/ATOM-16458

Change the DiffuseProbeGrid component to an OBB

Gems/Atom/Feature/Common/Code/Source/DiffuseGlobalIllumination/DiffuseProbeGrid.cpp

@@ -128,8 +128,8 @@ namespace AZ
 
         void DiffuseProbeGrid::SetTransform(const AZ::Transform& transform)
         {
-            m_position = transform.GetTranslation();
-            m_aabbWs = Aabb::CreateCenterHalfExtents(m_position, m_extents / 2.0f);
+            m_transform = transform;
+            m_obbWs = Obb::CreateFromPositionRotationAndHalfLengths(m_transform.GetTranslation(), m_transform.GetRotation(), m_extents / 2.0f);
 
             // probes need to be relocated since the grid position changed
             m_remainingRelocationIterations = DefaultNumRelocationIterations;
@@ -145,7 +145,7 @@ namespace AZ
         void DiffuseProbeGrid::SetExtents(const AZ::Vector3& extents)
         {
             m_extents = extents;
-            m_aabbWs = Aabb::CreateCenterHalfExtents(m_position, m_extents / 2.0f);
+            m_obbWs = Obb::CreateFromPositionRotationAndHalfLengths(m_transform.GetTranslation(), m_transform.GetRotation(), m_extents / 2.0f);
 
             // recompute the number of probes since the extents changed
             UpdateProbeCount();
@@ -467,7 +467,10 @@ namespace AZ
             RHI::ShaderInputConstantIndex constantIndex;
 
             constantIndex = srgLayout->FindShaderInputConstantIndex(AZ::Name("m_probeGrid.origin"));
-            srg->SetConstant(constantIndex, m_position);
+            srg->SetConstant(constantIndex, m_transform.GetTranslation());
+
+            constantIndex = srgLayout->FindShaderInputConstantIndex(AZ::Name("m_probeGrid.rotation"));
+            srg->SetConstant(constantIndex, m_transform.GetRotation());
 
             constantIndex = srgLayout->FindShaderInputConstantIndex(AZ::Name("m_probeGrid.numRaysPerProbe"));
             srg->SetConstant(constantIndex, m_numRaysPerProbe);
@@ -760,14 +763,15 @@ namespace AZ
             RHI::ShaderInputImageIndex imageIndex;
 
             constantIndex = srgLayout->FindShaderInputConstantIndex(Name("m_modelToWorld"));
-            AZ::Matrix3x4 modelToWorld = AZ::Matrix3x4::CreateFromMatrix3x3AndTranslation(Matrix3x3::CreateIdentity(), m_position) * AZ::Matrix3x4::CreateScale(m_extents);
+            AZ::Matrix3x4 modelToWorld = AZ::Matrix3x4::CreateFromTransform(m_transform) * AZ::Matrix3x4::CreateScale(m_extents);
             m_renderObjectSrg->SetConstant(constantIndex, modelToWorld);
 
-            constantIndex = srgLayout->FindShaderInputConstantIndex(Name("m_aabbMin"));
-            m_renderObjectSrg->SetConstant(constantIndex, m_aabbWs.GetMin());
+            constantIndex = srgLayout->FindShaderInputConstantIndex(Name("m_modelToWorldInverse"));
+            AZ::Matrix3x4 modelToWorldInverse = AZ::Matrix3x4::CreateFromTransform(m_transform).GetInverseFull();
+            m_renderObjectSrg->SetConstant(constantIndex, modelToWorldInverse);
 
-            constantIndex = srgLayout->FindShaderInputConstantIndex(Name("m_aabbMax"));
-            m_renderObjectSrg->SetConstant(constantIndex, m_aabbWs.GetMax());
+            constantIndex = srgLayout->FindShaderInputConstantIndex(Name("m_obbHalfLengths"));
+            m_renderObjectSrg->SetConstant(constantIndex, m_obbWs.GetHalfLengths());
 
             constantIndex = srgLayout->FindShaderInputConstantIndex(Name("m_enableDiffuseGI"));
             m_renderObjectSrg->SetConstant(constantIndex, m_enabled);
@@ -821,13 +825,14 @@ namespace AZ
             lod.m_screenCoverageMax = 1.0f;
 
             // update cullable bounds
+            Aabb aabbWs = Aabb::CreateFromObb(m_obbWs);
             Vector3 center;
             float radius;
-            m_aabbWs.GetAsSphere(center, radius);
+            aabbWs.GetAsSphere(center, radius);
 
             m_cullable.m_cullData.m_boundingSphere = Sphere(center, radius);
-            m_cullable.m_cullData.m_boundingObb = m_aabbWs.GetTransformedObb(AZ::Transform::CreateIdentity());
-            m_cullable.m_cullData.m_visibilityEntry.m_boundingVolume = m_aabbWs;
+            m_cullable.m_cullData.m_boundingObb = m_obbWs;
+            m_cullable.m_cullData.m_visibilityEntry.m_boundingVolume = aabbWs;
             m_cullable.m_cullData.m_visibilityEntry.m_userData = &m_cullable;
             m_cullable.m_cullData.m_visibilityEntry.m_typeFlags = AzFramework::VisibilityEntry::TYPE_RPI_Cullable;
 

Gems/Atom/Feature/Common/Code/Source/DiffuseGlobalIllumination/DiffuseProbeGrid.h

@@ -72,7 +72,7 @@ namespace AZ
             const AZ::Vector3& GetExtents() const { return m_extents; }
             void SetExtents(const AZ::Vector3& extents);
 
-            const AZ::Aabb& GetAabbWs() const { return m_aabbWs; }
+            const AZ::Obb& GetObbWs() const { return m_obbWs; }
 
             bool ValidateProbeSpacing(const AZ::Vector3& newSpacing);
             const AZ::Vector3& GetProbeSpacing() const { return m_probeSpacing; }
@@ -183,14 +183,14 @@ namespace AZ
             // scene
             RPI::Scene* m_scene = nullptr;
 
-            // probe grid position
-            AZ::Vector3 m_position = AZ::Vector3(0.0f, 0.0f, 0.0f);
+            // probe grid transform
+            AZ::Transform m_transform = AZ::Transform::CreateIdentity();
 
             // extents of the probe grid
             AZ::Vector3 m_extents = AZ::Vector3(0.0f, 0.0f, 0.0f);
 
-            // probe grid AABB (world space), built from position and extents
-            AZ::Aabb m_aabbWs = AZ::Aabb::CreateNull();
+            // probe grid OBB (world space), built from transform and extents
+            AZ::Obb m_obbWs;
 
             // per-axis spacing of probes in the grid
             AZ::Vector3 m_probeSpacing;

Gems/Atom/Feature/Common/Code/Source/DiffuseGlobalIllumination/DiffuseProbeGridFeatureProcessor.cpp

@@ -154,10 +154,11 @@ namespace AZ
                 // sort the probes by descending inner volume size, so the smallest volumes are rendered last
                 auto sortFn = [](AZStd::shared_ptr<DiffuseProbeGrid> const& probe1, AZStd::shared_ptr<DiffuseProbeGrid> const& probe2) -> bool
                 {
-                    const Aabb& aabb1 = probe1->GetAabbWs();
-                    const Aabb& aabb2 = probe2->GetAabbWs();
-                    float size1 = aabb1.GetXExtent() * aabb1.GetZExtent() * aabb1.GetYExtent();
-                    float size2 = aabb2.GetXExtent() * aabb2.GetZExtent() * aabb2.GetYExtent();
+                    const Obb& obb1 = probe1->GetObbWs();
+                    const Obb& obb2 = probe2->GetObbWs();
+                    float size1 = obb1.GetHalfLengthX() * obb1.GetHalfLengthZ() * obb1.GetHalfLengthY();
+                    float size2 = obb2.GetHalfLengthX() * obb2.GetHalfLengthZ() * obb2.GetHalfLengthY();
+
                     return (size1 > size2);
                 };