How to get 3D object Coordinates?

General Discussion
1

I create a rectangle by render , I want to konw the four vertexs of the rectangle in screen？ how to implement?

Thanks

2

Do you already know the 3D world-coordinates of the rectangle’s vertices? If so (and since you created the rectangle I’m guessing that you do), then–if I understand you correctly–I think that you want the “project” method; if you’re using the default camera, then you would use something along the lines of “base.camLens.project(3dPt, 2dPt)” for each vertex.