Talk:Rendering system improvements

Suggestions

If we rendered it to just render where the camera is pointing, couldn't we get faster frame rates, because it seems like useless rendering to render absolutely everything (even if you're not looking at it).

Yes, of course the parts of scenery not visible should not be rendered, and that's one thing that OSG does for us. It's called view frustrum culling, and if I remember correctly, the cull thread takes most time per frame in flightgear.

- Zan

I'm not absolutely sure how to go about this one, but (I'm sorry for being such an X-Plane fan) couldn't we do sort of like what X-Plane does? So you'd only have to render high quality graphics a close distance to the plane, and further out, the pixels could be a little blurry, but since no one's able to clearly see it that far away, you might as well make it a little bit more blurry. I think that a lot of what Austin (lead developer of X-Plane) says on his "What's New" page is very useful information, and maybe we should take some advice from it.

This is called level of detail or LOD. We have some kind of LOD schemes currently in flightgear (like trees are visible only when near etc) but better LOD would indeed give better performance and looks. With clouds for example, it could mean using smaller textures farther away, and for terrain, using one baked texture for whole scenery tile insted of different materials. I think there have been some discussion about LOD before, I could search for them and link them up, as it is an important aspect.

Also, should probably use simpler shaders when objects are far away... even though that itself brings LOD since there is less pixels to render.

And the new X-Plane screenshots indeed look great. [1]

- Zan