Re: Ambocc environment sample

["Ahmidou Lyazidi" <ahmidou.xsi(at)gmail.com>]

Ctrl_occlusion is doing it, i think

2008/2/14, Andi Farhall <andi.farhall(at)vtr.co.uk>:

I've been looking at the sample environment function in the xsi ambocc node and i have to say i've been impressed with it. Quick and cheap image based lighting, no flickering or fizzing. I've never got final gathering to work well enough on moving images so this has been a pleasant surprise, but i think i am missing something about final gathering.

My understanding of the abocc shader is, eye ray hits object, bounces back a load of samplec in a cone, the angle being the spread - around the surface normal until it hits something or runs out of maximum distance or in the case of env sampling just hits nothing, and works out the amount of occlusion by the results of the samples. There is no fizzing or whatever if you set the number of samples to be high enough.

My (mis)understanding of final gathering is that it's essentially the same although i've never been  completely sure, spatially speaking, what the min and max radius (5.11) is controlling. So fg fizzes and pops and amboc doesn't.

Firstly, is there an amboc way to sample colour values from surrounding geomtry rather than just the environment shader? I'm assuming there isn't, but if there was, is there something inherent and complex that i am missing that would give you the same problems as just switching on FG. I'm just looking to expand the env sample function to incorporate the rest of the scene.

I hope i've made sence.

Andi.