It seems we can not change text element’s material ?
There is no option in the online editor.
In the engine, it will always use the default material:
_updateMaterial: function (screenSpace) {
if (screenSpace) {
this._material = this._system.defaultScreenSpaceTextMaterial;
if (this._meshInstance) this._meshInstance.layer = pc.scene.LAYER_HUD;
} else {
this._material = this._system.defaultTextMaterial;
if (this._meshInstance) this._meshInstance.layer = pc.scene.LAYER_WORLD;
}
if (this._meshInstance) {
this._meshInstance.material = this._material;
this._meshInstance.screenSpace = screenSpace;
}
}