From 92510df37386a952a490f72d304dc8d0087a94e4 Mon Sep 17 00:00:00 2001
From: Alex Peterson <26804013+AMZN-alexpete@users.noreply.github.com>
Date: Tue, 16 Nov 2021 16:34:43 -0800
Subject: [PATCH] Fix missing clip to world matrix data (#5677)

Signed-off-by: Alex Peterson <26804013+AMZN-alexpete@users.noreply.github.com>
---
 Gems/Atom/RPI/Code/Include/Atom/RPI.Public/View.h | 2 ++
 Gems/Atom/RPI/Code/Source/RPI.Public/View.cpp     | 8 ++++++++
 2 files changed, 10 insertions(+)

diff --git a/Gems/Atom/RPI/Code/Include/Atom/RPI.Public/View.h b/Gems/Atom/RPI/Code/Include/Atom/RPI.Public/View.h
index cdaf59ff75..e5614161b2 100644
--- a/Gems/Atom/RPI/Code/Include/Atom/RPI.Public/View.h
+++ b/Gems/Atom/RPI/Code/Include/Atom/RPI.Public/View.h
@@ -92,6 +92,8 @@ namespace AZ
             const AZ::Matrix4x4& GetViewToWorldMatrix() const;
             const AZ::Matrix4x4& GetViewToClipMatrix() const;
             const AZ::Matrix4x4& GetWorldToClipMatrix() const;
+            const AZ::Matrix4x4& GetClipToWorldMatrix() const;
+
             //! Get the camera's world transform, converted from the viewToWorld matrix's native y-up to z-up
             AZ::Transform GetCameraTransform() const;
 
diff --git a/Gems/Atom/RPI/Code/Source/RPI.Public/View.cpp b/Gems/Atom/RPI/Code/Source/RPI.Public/View.cpp
index 8c1e38ba58..4538cf83e4 100644
--- a/Gems/Atom/RPI/Code/Source/RPI.Public/View.cpp
+++ b/Gems/Atom/RPI/Code/Source/RPI.Public/View.cpp
@@ -125,6 +125,7 @@ namespace AZ
 
             m_worldToViewMatrix = worldToView;
             m_worldToClipMatrix = m_viewToClipMatrix * m_worldToViewMatrix;
+            m_clipToWorldMatrix = m_worldToClipMatrix.GetInverseFull();
 
             m_onWorldToViewMatrixChange.Signal(m_worldToViewMatrix);
             m_onWorldToClipMatrixChange.Signal(m_worldToClipMatrix);
@@ -162,6 +163,7 @@ namespace AZ
             m_worldToViewMatrix = m_viewToWorldMatrix.GetInverseFast();
 
             m_worldToClipMatrix = m_viewToClipMatrix * m_worldToViewMatrix;
+            m_clipToWorldMatrix = m_worldToClipMatrix.GetInverseFull();
 
             // Only signal an update when there is a change, otherwise this might block
             // user input from changing the value.
@@ -177,6 +179,7 @@ namespace AZ
             m_viewToClipMatrix = viewToClip;
 
             m_worldToClipMatrix = m_viewToClipMatrix * m_worldToViewMatrix;
+            m_clipToWorldMatrix = m_worldToClipMatrix.GetInverseFull();
 
             // Update z depth constant simultaneously
             // zNear -> n, zFar -> f
@@ -227,6 +230,11 @@ namespace AZ
             return m_worldToClipMatrix;
         }
 
+        const AZ::Matrix4x4& View::GetClipToWorldMatrix() const
+        {
+            return m_clipToWorldMatrix;
+        }
+
         bool View::HasDrawListTag(RHI::DrawListTag drawListTag)
         {
             return drawListTag.IsValid() && m_drawListMask[drawListTag.GetIndex()];