From 9de1ba5001faae8f4d663ef60d66b7e67154bb83 Mon Sep 17 00:00:00 2001
From: Nicholas McCoy <mccoyn@gmail.com>
Date: Mon, 17 Feb 2025 20:26:36 -0500
Subject: [PATCH] Apply translate and rotate to user_defined cameras.

---
 source/core/render/tracepixel.cpp | 61 ++++++++++++++++++++-----------
 source/core/scene/camera.cpp      | 17 ++++++++-
 source/core/scene/camera.h        |  1 +
 3 files changed, 56 insertions(+), 23 deletions(-)

diff --git a/source/core/render/tracepixel.cpp b/source/core/render/tracepixel.cpp
index 58bb16910..12ca1907c 100644
--- a/source/core/render/tracepixel.cpp
+++ b/source/core/render/tracepixel.cpp
@@ -873,32 +873,51 @@ bool TracePixel::CreateCameraRay(Ray& ray, DBL x, DBL y, DBL width, DBL height,
             break;
 
         case USER_DEFINED_CAMERA:
-            // Convert the x coordinate to be a DBL from -0.5 to 0.5.
-            x0 = x / width - 0.5;
+            {
+                // Convert the x coordinate to be a DBL from -0.5 to 0.5.
+                x0 = x / width - 0.5;
 
-            // Convert the y coordinate to be a DBL from -0.5 to 0.5.
-            y0 = 0.5 - y / height;
+                // Convert the y coordinate to be a DBL from -0.5 to 0.5.
+                y0 = 0.5 - y / height;
 
-            for (unsigned int i = 0; i < 3; ++i)
-            {
-                if (camera.Location_Fn[i] != nullptr)
-                    cameraLocation[i] = mpCameraLocationFn[i]->Evaluate(x0, y0);
-                if (!IsFinite(cameraLocation[i]))
-                    return false;
-                if (camera.Direction_Fn[i] != nullptr)
-                    cameraDirection[i] = mpCameraDirectionFn[i]->Evaluate(x0, y0);
-                if (!IsFinite(cameraDirection[i]))
+                bool bLocationFunction = false;
+                bool bDirectionFunction = false;
+
+                for (unsigned int i = 0; i < 3; ++i)
+                {
+                    if (camera.Location_Fn[i] != nullptr)
+                    {
+                        cameraLocation[i] = mpCameraLocationFn[i]->Evaluate(x0, y0);
+                        bLocationFunction = true;
+                    }
+                    if (!IsFinite(cameraLocation[i]))
+                        return false;
+
+                    if (camera.Direction_Fn[i] != nullptr)
+                    {
+                        cameraDirection[i] = mpCameraDirectionFn[i]->Evaluate(x0, y0);
+                        bDirectionFunction = true;
+                    }
+                    if (!IsFinite(cameraDirection[i]))
+                        return false;
+                }
+
+                if (bLocationFunction)
+                    MTransPoint(cameraLocation, cameraLocation, camera.UserTrans);
+
+                if (bDirectionFunction)
+                    MTransDirection(cameraDirection, cameraDirection, camera.UserTrans);
+
+                if (cameraDirection.IsNearNull(EPSILON))
                     return false;
-            }
-            if (cameraDirection.IsNearNull(EPSILON))
-                return false;
-            ray.Origin    = cameraLocation;
-            ray.Direction = cameraDirection;
+                ray.Origin    = cameraLocation;
+                ray.Direction = cameraDirection;
 
-            if(useFocalBlur)
-                JitterCameraRay(ray, x, y, ray_number);
+                if(useFocalBlur)
+                    JitterCameraRay(ray, x, y, ray_number);
 
-            InitRayContainerState(ray, true);
+                InitRayContainerState(ray, true);
+            }
             break;
 
         default:
diff --git a/source/core/scene/camera.cpp b/source/core/scene/camera.cpp
index d863d3ea5..2f69bb233 100644
--- a/source/core/scene/camera.cpp
+++ b/source/core/scene/camera.cpp
@@ -75,7 +75,10 @@ namespace pov
 
 void Camera::Translate(const Vector3d& Vector)
 {
-    Location += Vector;
+    TRANSFORM Trans;
+
+    Compute_Translation_Transform(&Trans, Vector);
+    Transform(&Trans);
 }
 
 
@@ -183,7 +186,9 @@ void Camera::Transform(const TRANSFORM *Trans)
     MTransPoint(Location, Location, Trans);
     MTransDirection(Direction, Direction, Trans);
     MTransDirection(Up, Up, Trans);
-    MTransDirection(Right, Right, Trans);
+    MTransDirection(Right, Right, Trans);  
+    
+    Compose_Transforms (UserTrans, Trans);
 }
 
 
@@ -257,6 +262,8 @@ void Camera::Init()
         Location_Fn[i]  = nullptr;
         Direction_Fn[i] = nullptr;
     }
+
+    UserTrans = Create_Transform();
 }
 
 /*****************************************************************************
@@ -384,6 +391,10 @@ Camera& Camera::operator=(const Camera& src)
 
     }
 
+    if (UserTrans != nullptr)
+        Destroy_Transform(UserTrans);
+    UserTrans = (src.UserTrans ? Copy_Transform(src.UserTrans) : nullptr);
+
     return *this;
 }
 
@@ -397,6 +408,7 @@ Camera::Camera(const Camera& src)
         Location_Fn[i]  = nullptr;
         Direction_Fn[i] = nullptr;
     }
+    UserTrans = nullptr;
     operator=(src);
 }
 
@@ -441,6 +453,7 @@ Camera::~Camera()
         if (Direction_Fn[i] != nullptr)
             delete Direction_Fn[i];
     }
+    Destroy_Transform(UserTrans);
 }
 
 }
diff --git a/source/core/scene/camera.h b/source/core/scene/camera.h
index 38bcc8c66..c9b8fd059 100644
--- a/source/core/scene/camera.h
+++ b/source/core/scene/camera.h
@@ -100,6 +100,7 @@ class Camera
     PIGMENT *Bokeh;                 // Pigment to use for the bokeh
     GenericScalarFunctionPtr Location_Fn[3];  // [USER_DEFINED_CAMERA] Set of functions defining the ray's origin for each screen position.
     GenericScalarFunctionPtr Direction_Fn[3]; // [USER_DEFINED_CAMERA] Set of functions defining the ray's direction for each screen position.
+    TRANSFORM *UserTrans;           // [USER_DEFINED_CAMERA] Transformation to apply after calculating functions
 
     // the following declarations are used for the mesh camera
     unsigned int Face_Distribution_Method;  // how to associate a pixel to a face within a mesh