Caustics photon map not using 100%.....& other problems

[timmatron]

This is the first time I've really used this feature, but it's only using about 50% of the cpu power. I have HT Xeons, and only 2 of the 4 are peaking.

Is this maybe another issue related with the bitmap pager or something?

Also, it's driving the memory way up. Last time it crashed at about 2.5 gig while trying to compute the map.

[timmatron]

Well I noticed it uses 100% at first and then towards the end drops off to either 50% or 25% as it's doing now. I wonder why it would do that....

[timmatron]

Ok, so here's my next problem....I can't get the caustics to render correctly.

Here are images created with and without caustics turned on. The caustic map used here took quite a few minutes to compute, and the size of it is about 300mb. The problem is that is is blocking all direct light coming through. I have caustics turned up to about 10,000 on the lights in the shelves & still nothing. Any ideas?

Caustics off:


Caustics on:

[RErender]

I'm not positive if it is the case for photons but if you notice in say a imap calc the regions are devided up to all the processes, when it gets to the last few regions the cpu usage will drop as each process finishes it's final task. Then they will jump back up to 100% as they start the final render. I suspect it is the same with the photons.

The issue with the caustics is that the vraymtl turns off "affect shadows" so that the only the caustics can get through. What ior is your glass? It would have to be pretty correct to work. I'd try turning on reflective and refractive caustics to lighten things up in there.

[timmatron]

Thanks Eric,

You might be right with the caustic photons being divided up to each processor. But unlike imaps, you can't say how big the bucket size will be. So if the caustic photon map only divides it up into 4 sections, then I end up with 3 processors not doing anything for almost just as long as it took them to finish their jobs. Something just doesn't seem right about it. I mean, lightmaps don't work that way.

And regarding the other issue... Last night I was trying to render a simple scene with a sheet of 1/2" glass floating about 6" over a plane with a solid color to see if I could figure out how to make caustics work right. Its a lot harder than I thought. I end up with something that looks more like swimming pool water than what a sheet of glass should be doing. For IOR, it's set at the default 1.56 for EGZ's glass.

[samuel_bubat]

Hi there,

Are these max photometric Lights ?
Not shure but I think caustics are not supported by photometric lights.

[timmatron]

Uh-oh...maybe that's why. I am using ies lights on those shelves.

But even for my test I was only using a target direct and that was difficult enough.

Thanks for the heads up though.

It would be nice to hear from the V-man himself to offer any pointers.