It is supposed that any visual things out of camera frustum area should not be rendered…right ?

but in Away 3d, when i get the mesh out of camera frustum,and made the camera frustum area contains nothing,  the POLY number did decreased a lots, but the frame rate still remain the same(still very low) ,it seems that the GPU is still working very intensely… it’s not reasonable…Is that a bug ?

Not necessarily. Triangle-Count is not the only thing that may contribute to a low frame rate. From my own test, in fact, I noticed that Triangle-Count is one of the most irrelevant factors for a low frame rate, depending on the GPU you have.

As most modern day GPUs can easily handle millions of triangles at a time, their shader units are sometimes the real bottle neck. As per-pixel lighting done on GPU is the default case in Away3D, having one single plane covering most of the view frustum and being shaded can cause a major drop in frame rate on low-end GPUs as found on many laptop computers. Triangle-Count, in that case, is irrelevant.

I’d guess that if the poly counter decreases, frustum culling is done correctly.
Is there anything else within the frustum that is rendered?
Is there any CPU processing going on? Slow AS3 execution also results in a low frame rate.

Cheers!
Alex

“I noticed that Triangle-Count is one of the most irrelevant factors for a low frame rate, depending on the GPU you have…”

Agree! Strongly Agree!

I tried a lot using the Merge class to reduce the mesh and poly number of my scene , but it only contributes a little ...very little…for performance tunning…

Alex, there is only one ObjectContainer3D in my view.scene, i put all my meshes in this container ,even the 9 lights ....the CPU is 31% occupied on average, when the browser is shut down , the CUP is 2-5% occupied…some of the task did occupied the CPU resource,but not very high, what kind of stuff take up my GPU and make it work so intensely ?

This has a tendency to it to become interesting :D

Do you have that example ready to share with us? =)