Merge pull request #12611 from Hiwen/Texture3D

Support Texture3D and add Volume Cloud SandBox Sample

Author: jjhembd

Apps/Sandcastle/gallery/development/VolumeCloud.html

@@ -1,5 +1,13 @@
 # Change Log
 
+## 1.130 - 2025-06-02
+
+### @cesium/engine
+
+#### Additions :tada:
+
+- Support Texture3D and add Volume Cloud SandBox Sample. [#12550](https://github.com/CesiumGS/cesium/issues/12550)
+
 ## 1.129 - 2025-05-01
 
 ### @cesium/engine

Apps/Sandcastle/gallery/development/VolumeCloud.jpg

@@ -392,6 +392,29 @@ PixelFormat.textureSizeInBytes = function (
   );
 };
 
+/**
+ * @private
+ */
+PixelFormat.texture3DSizeInBytes = function (
+  pixelFormat,
+  pixelDatatype,
+  width,
+  height,
+  depth,
+) {
+  let componentsLength = PixelFormat.componentsLength(pixelFormat);
+  if (PixelDatatype.isPacked(pixelDatatype)) {
+    componentsLength = 1;
+  }
+  return (
+    componentsLength *
+    PixelDatatype.sizeInBytes(pixelDatatype) *
+    width *
+    height *
+    depth
+  );
+};
+
 /**
  * @private
  */
@@ -499,6 +522,19 @@ PixelFormat.toInternalFormat = function (pixelFormat, pixelDatatype, context) {
     }
   }
 
+  if (pixelDatatype === PixelDatatype.UNSIGNED_BYTE) {
+    switch (pixelFormat) {
+      case PixelFormat.RGBA:
+        return WebGLConstants.RGBA8;
+      case PixelFormat.RGB:
+        return WebGLConstants.RGB8;
+      case PixelFormat.RG:
+        return WebGLConstants.RG8;
+      case PixelFormat.RED:
+        return WebGLConstants.R8;
+    }
+  }
+
   return pixelFormat;
 };