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


BSP without PVS

Recommended Posts

Original post by RavNaz

Anyway that a BSP renderer can be sped up without the use of PVS?

BSP were first used to sort polygons without using a Z-buffer (when you render a BSP node, first render the child which is not on the same side of the plane as the viewpoint, and second the child on the same side. Doing it recusively will sort the scene).
PVS were used by Caramack in Doom (2D BSP sorting) and Quake (3D BSP) to reduce the amount of rendered BSP cells. You can do portal rendering with BSP - but a standard BSP compilator produce a large amount of portals and real-time portal visibility evaluation will be slower. It''s the reason why PVS are precomputed (and why it takes a long time to compute .
Nowadays, as Z-Buffer are implemented on hardware, BSP sorting is not as interesting as before. I think that without PVS it will be difficult to render efficiently a BSP tree. But the way PVS are computed can be discussed. Moreover, BSP are not only interesting for rendering but also for lighting precomputation, collision detection, path finding ...

That''s all.

"The reasonable man adapts himself to the world;
the unreasonable man persists to adapt the world to himself.
Therefore, all progress depends on the unreasonable."
George Bernard Shaw

Share this post

Link to post
Share on other sites