Minor fixes

src/assetmanager/MaterialManager.ts

             .forEach(map=>
                 !map.isRenderTargetTexture && map.userData.disposeOnIdle !== false &&
                 map.dispose && !isInScene(map) && map.dispose())
-        this.unregisterMaterial(mat) // todo, re-add when material is added again to the scene.
+        // this.unregisterMaterial(mat) // not unregistering on dispose, that has to be done explicitly. todo: make an easy way to do that.
     }
 
     private _materialMaps = new Map<string, Set<ITexture>>()

src/rendering/RenderManager.ts

 
     protected _createTargetClass(clazz: Class<WebGLRenderTarget>, size: number[], options: WebGLRenderTargetOptions): IRenderTarget {
         const processNewTarget = this._processNewTarget
+        const disposeTarget = this.disposeTarget.bind(this)
         return new class RenderTarget extends clazz implements IRenderTarget {
             isTemporary?: boolean
             sizeMultiplier?: number
                 super.copy(source as any)
                 return this
             }
-
+            // Note - by default unregister need to be false.
+            dispose(unregister = false) {
+                if (unregister === true) disposeTarget(this, true)
+                else super.dispose()
+            }
         }(this, ...size, options)
     }
 

src/rendering/RenderTargetManager.ts

         return target
     }
 
-    disposeTarget(target: IRenderTarget): void {
+    /**
+     * Dispose and remove tracked target. Release target in-case of temporary target.
+     * To just dispose from the GPU memory and keep reference, call `target.dispose()` or `target.dispose(false)`
+     * @param target
+     * @param remove
+     */
+    disposeTarget(target: IRenderTarget, remove = true): void {
         if (!target) return
         if (target.isTemporary) return this.releaseTempTarget(target)
-        this.removeTrackedTarget(target)
-        target.dispose()
+        if (remove) this.removeTrackedTarget(target)
+        // @ts-expect-error internal, not in types
+        target.dispose(false) // false is not required but still passing so that it doesnt cause infinite loop in future.
     }
 
     getTempTarget<T extends IRenderTarget = IRenderTarget>(op: CreateRenderTargetOptions = {}): T {

src/viewer/ThreeViewer.ts

         ;(window as any).threeViewers?.splice((window as any).threeViewers.indexOf(this), 1)
 
         if (this.resizeObserver) this.resizeObserver.unobserve(this._canvas)
-        else window.removeEventListener('resize', this.resize)
+        window.removeEventListener('resize', this.resize)
 
         this.dispatchEvent({type: 'dispose'})
     }