dirty mechanism

src/Engines/constants.ts

@@ -282,9 +282,13 @@ export class Constants {
      */
     public static readonly MATERIAL_MiscDirtyFlag = 16;
     /**
+     * The dirty prepass flag value
+     */
+    public static readonly MATERIAL_PrePassDirtyFlag = 32;
+    /**
      * The all dirty flag value
      */
-    public static readonly MATERIAL_AllDirtyFlag = 31;
+    public static readonly MATERIAL_AllDirtyFlag = 63;
 
     /**
      * Returns the triangle fill mode

src/Materials/material.ts

@@ -130,6 +130,11 @@ export class Material implements IAnimatable {
     public static readonly MiscDirtyFlag = Constants.MATERIAL_MiscDirtyFlag;
 
     /**
+     * The dirty prepass flag value
+     */
+    public static readonly PrePassDirtyFlag = Constants.MATERIAL_PrePassDirtyFlag;
+
+    /**
      * The all dirty flag value
      */
     public static readonly AllDirtyFlag = Constants.MATERIAL_AllDirtyFlag;
@@ -1156,6 +1161,7 @@ export class Material implements IAnimatable {
     private static readonly _TextureDirtyCallBack = (defines: MaterialDefines) => defines.markAsTexturesDirty();
     private static readonly _FresnelDirtyCallBack = (defines: MaterialDefines) => defines.markAsFresnelDirty();
     private static readonly _MiscDirtyCallBack = (defines: MaterialDefines) => defines.markAsMiscDirty();
+    private static readonly _PrePassDirtyCallBack = (defines: MaterialDefines) => defines.markAsPrePassDirty();
     private static readonly _LightsDirtyCallBack = (defines: MaterialDefines) => defines.markAsLightDirty();
     private static readonly _AttributeDirtyCallBack = (defines: MaterialDefines) => defines.markAsAttributesDirty();
 
@@ -1207,6 +1213,10 @@ export class Material implements IAnimatable {
             Material._DirtyCallbackArray.push(Material._MiscDirtyCallBack);
         }
 
+        if (flag & Material.PrePassDirtyFlag) {
+            Material._DirtyCallbackArray.push(Material._PrePassDirtyCallBack);
+        }
+
         if (Material._DirtyCallbackArray.length) {
             this._markAllSubMeshesAsDirty(Material._RunDirtyCallBacks);
         }
@@ -1313,6 +1323,13 @@ export class Material implements IAnimatable {
     }
 
     /**
+     * Indicates that prepass needs to be re-calculated for all submeshes
+     */
+    protected _markAllSubMeshesAsPrePassDirty() {
+        this._markAllSubMeshesAsDirty(Material._MiscDirtyCallBack);
+    }
+
+    /**
      * Indicates that textures and misc need to be re-calculated for all submeshes
      */
     protected _markAllSubMeshesAsTexturesAndMiscDirty() {

src/Materials/materialDefines.ts

@@ -21,6 +21,8 @@ export class MaterialDefines {
     /** @hidden */
     public _areMiscDirty = true;
     /** @hidden */
+    public _arePrePassDirty = true;
+    /** @hidden */
     public _areImageProcessingDirty = true;
 
     /** @hidden */
@@ -53,6 +55,7 @@ export class MaterialDefines {
         this._areLightsDirty = false;
         this._areLightsDisposed = false;
         this._areMiscDirty = false;
+        this._arePrePassDirty = false;
         this._areImageProcessingDirty = false;
     }
 
@@ -127,6 +130,14 @@ export class MaterialDefines {
     }
 
     /**
+     * Marks the prepass state as changed
+     */
+    public markAsPrePassDirty() {
+        this._arePrePassDirty = true;
+        this._isDirty = true;
+    }
+
+    /**
      * Rebuilds the material defines
      */
     public rebuild() {

src/Materials/materialHelper.ts

@@ -311,6 +311,11 @@ export class MaterialHelper {
      */
     public static PrepareDefinesForPrePass(scene: Scene, defines: any, canRenderToMRT: boolean) {
         const previousPrePass = defines.PREPASS;
+
+        if (!defines._arePrePassDirty) {
+            return;
+        }
+
         const texturesList = [
         {
             type: Constants.PREPASS_POSITION_TEXTURE_TYPE,

src/Rendering/prePassRenderer.ts

@@ -10,6 +10,7 @@ import { Color4 } from "../Maths/math.color";
 import { PrePassEffectConfiguration } from "./prePassEffectConfiguration";
 import { Nullable } from "../types";
 import { AbstractMesh } from '../Meshes/abstractMesh';
+import { Material } from '../Materials/material';
 
 /**
  * Renders a pre pass of the scene
@@ -364,6 +365,7 @@ export class PrePassRenderer {
      */
     public markAsDirty() {
         this._isDirty = true;
+        this._markAllMaterialsAsPrePassDirty();
     }
 
     /**
@@ -420,6 +422,14 @@ export class PrePassRenderer {
         }
     }
 
+    private _markAllMaterialsAsPrePassDirty() {
+        const materials = this._scene.materials;
+
+        for (let i = 0; i < materials.length; i++) {
+            materials[i].markAsDirty(Material.PrePassDirtyFlag);
+        }
+    }
+
     /**
      * Disposes the prepass renderer.
      */