copy method
Implementation
@override
MeshDistanceMaterial copy(Material source) {
super.copy(source);
if (source is MeshDistanceMaterial) {
referencePosition.copy(source.referencePosition);
nearDistance = source.nearDistance;
farDistance = source.farDistance;
}
map = source.map;
alphaMap = source.alphaMap;
displacementMap = source.displacementMap;
displacementScale = source.displacementScale;
displacementBias = source.displacementBias;
return this;
}