public void setForcedMaterial(Material mat) {
        forcedMaterial = mat;
    }
Sets the material to use to render all future objects.
This overrides the material set on the geometry and renders
with the provided material instead.
Use null to clear the material and return renderer to normal
functionality.

@param mat The forced material to set, or null to return to normal
jme3-core/src/main/java/com/jme3/renderer/RenderManager.java