Hello

I need a ast shader for ambient occlusion, I am using 3Delight which i can access "occlusion" and "gather" functions. but the speed isn't good enough, ( actually not good at all).

Am i missing something, can u guys tell me a shader or ....


TIA

The occlusion speed depends on different things.
Do you raytrace displacements? That takes a lot of memory, especially if you displacement bound is not set properly. And if you computer starts to "swap", that really makes the render times unacceptable.
Do you bake the occlusion in a pointcloud? The bake3d() process can take time, especially if the cloud is big. (Big as in many points, not in units. So a lower shading rate, a bigger ptc, and a bigger image, a bigger ptc, I think.)
Are your samples too high for your needs? Is the max distance too high for your needs? Are the opaque objects flagged as "transmission" "shader" instead of "opaque"?
There can be other non-shader related elements that affect your render times.

And a potential solution: try to decrease the samples based on the distance to the camera. It may give acceptable results (especially when far objects are blurred by depth of field) with a considerable gain in render times.