Frustum culling on the CPU. Traverse your draw list and remove items that are outside the frustum, or don't add them in the first place.

You'll have to find some balance between the performance gain and the costs related to some method of frustrum culling. Maybe you'll realise that it actually is faster to render everything all the time (even in this case pixel shaders are NOT executed for pixels outside of the camera frustrum) than to spend CPU power on frustrum culling.

To be able to render only some objects you also must have your meshes divided, which means more draw calls - this applies especially to large static meshes like the terrain. Maybe it will be faster to render the whole terrain in one draw call than to render 10 pieces of the terrain out of 50 pieces?

But this is all MAYBE. It depends strongly on what actually are you rendering, what kind of game, how does is look like, how many objects there are and how complicated they are etc.

In some cases even a very simple, basic and cheap frustrum culling against axis-aligned bounding boxes or bounding spheres can give you huge performance gain.

To elaborate on what others have said, you want to go through all your objects/batches and test if they are inside the camera frustum. This is usually done by checking each object's bounding box against the camera frustum, which can easily become an expensive operation to perform.

However, it can be optimized in several ways:

• Including more geometry per batch (see Tom KQT and Krohm's post); this is only valid for static geometry though.
• Have some kind of tree data structure, such as an Octree so you can easily discard tons of tests by avoiding checking sub-objects of a huge container if the container itself is out of the frustum.

Note: Don't forget that you should still sort your objects by material (texture, shaders, etc) after gathering the visible objects (or while doing so) for maximum performance.

In some cases, occlusion culling is equally and sometimes more important and valuable than frustum culling. If you have a large scene, with the camera on one side facing the other - culling things outside the view won't prevent the entire scene from being dealt with - because it's still all within view, just likely to be covered up by the closest parts of the scene.

There are many resources, articles, and books, that delve into various algorithms and approaches for occlusion culling.

http://en.wikipedia.org/wiki/Hidden_surface_determination

Thanks guys,

Is there is anyway to cull anything which its depth is further than the appearing objects?

Any other suggestions to get high performance?

Is there is anyway to cull anything which its depth is further than the appearing objects?

Frustum culling, which has already been mentioned. A frustum has 6 sides, which include the near and far planes.

Maybe he was talking about culling objects which are hidden behind other visible objects, not which are further than the far clip plane.

In this case radioteeth's post applies (occlusion culling).