Archived

This topic is now archived and is closed to further replies.

3D Clipping question

This topic is 6580 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Ok guys, quick question. I'm writing my first 3d engine, real simple stuff. Flat shaded, nothing but triangles. Anyway, before making my poly list to send to the renderer, I have a simple 3d clipping filter. It excludes all polys outside the near and far clipping frustums, and the viewing planes. The problem is, I need to remove any poly that has even one vertice behind the near clipping frustum, or the projection will get all screwed up. How would I implement proper projection if a poly is partway past the clipping frustum, for example if there are two tris making a rectangular floor and the camera is in the middle? I've never actually seen anyone address this problem. For further clarification, here's a little diagram hope you're not using proportional fonts)

|
|
Camera |---->
|
| _____|_____ <- tri
|

There's gotta be a way to properly transform the tri, even though one of the vertices is behind the near frustum. Anyone have any suggestions?

Share this post


Link to post
Share on other sites