Solid particle "props" property

dist/preview release/what's new.md

@@ -11,5 +11,6 @@
 ## Bugs
 
 - Fix infinite loop in `GlowLayer.unReferenceMeshFromUsingItsOwnMaterial` ([Popov72](https://github.com/Popov72)
+- Fix picking issue in the Solid Particle System when MultiMaterial is enabled ([jerome](https://github.com/jbousquie))
 
 ## Breaking changes

src/Particles/solidParticle.ts

@@ -117,6 +117,10 @@ export class SolidParticle {
      */
     public materialIndex: Nullable<number> = null;
     /**
+     * Custom object or properties.
+     */
+    public props: Nullable<any> = null;
+    /**
      * The culling strategy to use to check whether the solid particle must be culled or not when using isInFrustum().
      * The possible values are :
      * - AbstractMesh.CULLINGSTRATEGY_STANDARD