From c821e1c19b29bb252dcbe5f614c5e0febbc81f70 Mon Sep 17 00:00:00 2001
From: treattrick <1154174767@qq.com>
Date: Wed, 13 May 2026 22:49:32 +0800
Subject: [PATCH] fix(vtkOpenGLImageCPRMapper): projectionScaledDirection
 should have vtkImageData direction matrix

---
 Sources/Rendering/OpenGL/ImageCPRMapper/index.js | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/Sources/Rendering/OpenGL/ImageCPRMapper/index.js b/Sources/Rendering/OpenGL/ImageCPRMapper/index.js
index 3e74f73796b..bc5247ef5c9 100644
--- a/Sources/Rendering/OpenGL/ImageCPRMapper/index.js
+++ b/Sources/Rendering/OpenGL/ImageCPRMapper/index.js
@@ -773,7 +773,6 @@ function vtkOpenGLImageCPRMapper(publicAPI, model) {
     ];
     if (useProjection) {
       tcoordFSDec.push(
-        'uniform vec3 volumeSizeMC;',
         'uniform int projectionSlabNumberOfSamples;',
         'uniform float projectionConstantOffset;',
         'uniform float projectionStepLength;'
@@ -930,7 +929,7 @@ function vtkOpenGLImageCPRMapper(publicAPI, model) {
 
       // Loop on all the samples of the projection
       tcoordFSImpl.push(
-        'vec3 projectionScaledDirection = projectionDirection / volumeSizeMC;',
+        'vec3 projectionScaledDirection = (MCTCMatrix * vec4(projectionDirection, 0.0)).xyz;',
         'vec3 projectionStep = projectionStepLength * projectionScaledDirection;',
         'vec3 projectionStartPosition = volumePosTC + projectionConstantOffset * projectionScaledDirection;',
         'vec4 tvalue = initialProjectionTextureValue;',
@@ -1199,16 +1198,11 @@ function vtkOpenGLImageCPRMapper(publicAPI, model) {
     }
     // Projection uniforms
     if (model.renderable.isProjectionEnabled()) {
-      const image = model.currentImageDataInput;
-      const spacing = image.getSpacing();
-      const dimensions = image.getDimensions();
       const projectionSlabThickness =
         model.renderable.getProjectionSlabThickness();
       const projectionSlabNumberOfSamples =
         model.renderable.getProjectionSlabNumberOfSamples();
 
-      const volumeSize = vec3.mul([], spacing, dimensions);
-      program.setUniform3fArray('volumeSizeMC', volumeSize);
       program.setUniformi(
         'projectionSlabNumberOfSamples',
         projectionSlabNumberOfSamples