[GRAPHICS] Fix hldx buffer format.

h3d/scene/Graphics.hx

@@ -68,8 +68,10 @@ class Graphics extends Mesh {
 		if( is3D == v )
 			return v;
 		if( v ) {
+			material.texture = h3d.mat.Texture.fromColor(-1);
 			material.mainPass.removeShader(lineShader);
 		} else {
+			material.texture = null;
 			material.mainPass.addShader(lineShader);
 		}
 		bprim.clear();