Face Culling / LOD and other queries

Game Engine Game Engine Support and Discussion
1

Hi Guys,

The thing is Im facing a severe lag due to a high number of polys. Monster has suggested some sort of LOD in order to draw only those faces that are within the camera’s frustum. From what I gain it is similar to the back culling technique native to opengl.

So Ive created this thread on Monster’s advice since this info might be beneficial to all.

Queries:

  1. How do I exactly implement this LOD?

  2. Ive got to load meshes dynamically at run time, possibly over the internet using gzipped meshes. Heard abt it in Campbell Barton’s thread on the topic but still dont know how. Any pointers for this?

  3. So now if these meshes are high poly, is it possible to convert them to low poly or have a normal map onto them again at runtime. Campbell had a polyreducer script in Blender 2.43 if Im not mistaken. So any pointers on how I can upgrade that script?

Thanks,
Chirag

2

Hi Stralen,

the wiki.blender.org is down, so it took me a while to find the correct thread.

  1. For LOD have a look into moerdn’s LOD Script based on KD-Tree. I think this is a good one.
  2. Check out the videos on the Dynamic Loading/freeingthread. You can see that it is possible to load .blend files. If you can manage to transfer the files through the net, you can use this to load it into the running scene.
  3. I do not know about realtime mesh polyreducer for blender. So I cna’t help with that.
3

I’ve made also a simple LOD for the Gtown Game, might be useful for someone as well.

Here’s is the link to the tutorial and the file example:
http://www.gtown.ch/index.php?option=com_content&view=article&id=85&catid=39&Itemid=103

4

Thanks for the replies :slight_smile: so a completely new thing to learn has gotten me quite excited. But before that, I have a small query…

The link above is to one of the coolest environment flythroughs Ive seen. Is it correct to say that with 185,000 tri’s the smoothness is achieved because of this LOD technique?