fix: correctly set back to state and buffer during VR if a second pas…

…s or histogram is used

src/perspective_view/panel.ts

@@ -1164,6 +1164,7 @@ export class PerspectivePanel extends RenderedDataPanel {
           );
         };
         bindVolumeRenderingBuffer();
+        renderContext.bindVolumeRenderingBuffer = bindVolumeRenderingBuffer;
         gl.clearDepth(1.0);
         gl.clearColor(0.0, 0.0, 0.0, 1.0);
         gl.clear(

src/perspective_view/render_layer.ts

@@ -71,6 +71,11 @@ export interface PerspectiveViewRenderContext
    */
   bindMaxProjectionBuffer?: () => void | undefined;
 
+  /**
+   * Specifies how to bind the volume rendering buffer
+   */
+  bindVolumeRenderingBuffer?: () => void | undefined;
+
   /**
    * Specifies how to assign the max projection emitter
    */

src/volume_rendering/volume_render_layer.ts

@@ -775,18 +775,20 @@ outputValue = vec4(1.0, 1.0, 1.0, 1.0);
       const performedSecondPassForPicking =
         !isProjectionMode(this.mode.value) &&
         !renderContext.isContinuousCameraMotionInProgress;
-      // In this case, we need the max projection buffer
+      // If the layer is in projection mode or the second pass for picking has been performed,
+      // the max projection state is needed
+      // the max projection buffer is not bound, because it is immediately read back
+      // in the perspective panel to update the max projection picking buffer
       if (isProjectionMode(this.mode.value) || performedSecondPassForPicking) {
         gl.depthMask(true);
         gl.disable(WebGL2RenderingContext.BLEND);
         gl.depthFunc(WebGL2RenderingContext.GREATER);
-        renderContext.bindMaxProjectionBuffer!();
       } else {
-        // Otherwise, the regular OIT buffer is needed
+        // Otherwise, the regular OIT buffer is needed along with the state
         gl.depthMask(false);
         gl.enable(WebGL2RenderingContext.BLEND);
         gl.depthFunc(WebGL2RenderingContext.LESS);
-        renderContext.bindFramebuffer();
+        renderContext.bindVolumeRenderingBuffer!();
       }
       gl.enable(WebGL2RenderingContext.DEPTH_TEST);
     };