From 02203ff134570c301ce58969397c296ee14e69ee Mon Sep 17 00:00:00 2001
From: Meta Vens <rwvens@hotmail.com>
Date: Thu, 16 Jul 2026 19:25:57 +0100
Subject: [PATCH] Preserve Unity shader camera transform semantics

---
 .../Fields/EveUnityFieldsVolumeRenderer.cs    |  5 +++-
 .../EveFieldsUnitySceneProjectionTests.cs     | 30 +++++++++++++++++++
 .../org.gamecult.eve.unity-scene/package.json |  2 +-
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/packages/org.gamecult.eve.unity-scene/Runtime/Fields/EveUnityFieldsVolumeRenderer.cs b/packages/org.gamecult.eve.unity-scene/Runtime/Fields/EveUnityFieldsVolumeRenderer.cs
index f4e823a..061d55c 100644
--- a/packages/org.gamecult.eve.unity-scene/Runtime/Fields/EveUnityFieldsVolumeRenderer.cs
+++ b/packages/org.gamecult.eve.unity-scene/Runtime/Fields/EveUnityFieldsVolumeRenderer.cs
@@ -140,7 +140,7 @@ namespace GameCult.Eve.UnityScene.Fields
             var gpuProjection = GL.GetGPUProjectionMatrix(camera.projectionMatrix, true);
             var viewProjection = gpuProjection * camera.worldToCameraMatrix;
             SetMatrixPort("cameraInverseViewProjection", viewProjection.inverse);
-            SetMatrixPort("cameraToWorld", camera.cameraToWorldMatrix);
+            SetMatrixPort("cameraToWorld", CameraTransformToWorld(camera));
             SetVectorPort("cameraProjectionExtents", ProjectionExtents(camera));
             SetFloatPort("raymarchOffset", Halton(Time.frameCount & 1023, 3));
 
@@ -594,6 +594,9 @@ namespace GameCult.Eve.UnityScene.Fields
             return new Vector4(y * camera.aspect, y, 0f, 0f);
         }
 
+        private static Matrix4x4 CameraTransformToWorld(Camera camera) =>
+            camera.transform.localToWorldMatrix;
+
         private static float Halton(int index, int radix)
         {
             var result = 0f;
diff --git a/packages/org.gamecult.eve.unity-scene/Tests/Editor/EveFieldsUnitySceneProjectionTests.cs b/packages/org.gamecult.eve.unity-scene/Tests/Editor/EveFieldsUnitySceneProjectionTests.cs
index a8349a4..3591dbd 100644
--- a/packages/org.gamecult.eve.unity-scene/Tests/Editor/EveFieldsUnitySceneProjectionTests.cs
+++ b/packages/org.gamecult.eve.unity-scene/Tests/Editor/EveFieldsUnitySceneProjectionTests.cs
@@ -2,6 +2,7 @@ using System;
 using System.IO;
 using System.Linq;
 using System.Collections.Generic;
+using System.Reflection;
 using GameCult.Eve.PluginFields;
 using GameCult.Eve.UnityScene.Fields;
 using NUnit.Framework;
@@ -12,6 +13,35 @@ namespace GameCult.Eve.UnityScene.Tests
 {
     public sealed class EveFieldsUnitySceneProjectionTests
     {
+        [Test]
+        public void VolumeCameraToWorldPreservesUnityShaderPositiveZForward()
+        {
+            var cameraObject = new GameObject("eve-volume-camera-matrix");
+            try
+            {
+                var camera = cameraObject.AddComponent<Camera>();
+                camera.transform.SetPositionAndRotation(
+                    new Vector3(12f, -3f, 8f),
+                    Quaternion.Euler(17f, 43f, -9f));
+                var method = typeof(EveUnityFieldsVolumeRenderer).GetMethod(
+                    "CameraTransformToWorld",
+                    BindingFlags.NonPublic | BindingFlags.Static);
+
+                Assert.That(method, Is.Not.Null);
+                var matrix = (Matrix4x4)method!.Invoke(null, new object[] { camera });
+                Assert.That(Vector3.Dot(
+                    matrix.MultiplyVector(Vector3.forward).normalized,
+                    camera.transform.forward), Is.EqualTo(1f).Within(0.00001f));
+                Assert.That(Vector3.Distance(
+                    matrix.MultiplyPoint3x4(Vector3.zero),
+                    camera.transform.position), Is.LessThan(0.00001f));
+            }
+            finally
+            {
+                UnityEngine.Object.DestroyImmediate(cameraObject);
+            }
+        }
+
         [Test]
         public void RasterizerConsumesPluginOwnedDocumentContract()
         {
diff --git a/packages/org.gamecult.eve.unity-scene/package.json b/packages/org.gamecult.eve.unity-scene/package.json
index 64b70e2..d3c13c8 100644
--- a/packages/org.gamecult.eve.unity-scene/package.json
+++ b/packages/org.gamecult.eve.unity-scene/package.json
@@ -1,7 +1,7 @@
 {
     "name": "org.gamecult.eve.unity-scene",
     "displayName": "Eve Unity Scene Lowering",
-    "version": "0.3.57",
+    "version": "0.3.58",
     "unity": "6000.0",
     "description": "Provider-agnostic Unity scene shell for gamecult.eve.surface.v1 interactive world surfaces.",
     "dependencies": {