unity3d中用2D背景当作图片

}

void Update(){

//reset texture if it has changed:

if( xture != image ){

xture = image;

}

//nothing needs to be recalculated if distance hasn't changed or a move/rotate was attempted on billboard moved withoutour permission:

if(distance == prevDistance &&

on == prevPosition &&

ulerAngles == prevRotation

) return;

//error for attempting a backdrop placement beyond camera's far clip plane:

if(distance > pPlane){

or("Backdrop's distance is further than the camera's far clip plane. Extend the camera's far clip plane orreduce the billboard's distance.");

return;

}

//error for attempting a backdrop placement before camera's near clip plane:

if(distance < ipPlane){

or("Backdrop's distance is closer than the camera's near clip plane. Extend the distance or reduce thecamera's near clip plane.");

return;

}

//set backdrop's placement:

on = d * distance;

//calculate mesh:

es = CalcVerts();

ulateNormals();

//readjust comparison values:

prevDistance = distance;

prevPosition = on;

prevRotation = ulerAngles;

}

Vector3[] CalcVerts()

{

return new Vector3[] {

eTransformPoint(ToWorldPoint(new Vector3(0,0,distance))),

eTransformPoint(ToWorldPoint(new Vector3(,0,distance))),

eTransformPoint(ToWorldPoint(new Vector3(0,,distance))),

eTransformPoint(ToWorldPoint(newVector3(,,distance)))

};

}

}