Merging HUGE irradiance maps - is it possible?

[emptyvoxel]

Hi people,

I recently split the irradiance map calculation of a very complex interior animation with some quick camera pans between two machines overnight. The result was two irr maps at around 600 MBs each.

I have tried every method I can find to merge these two maps together, but nothing is working.
Specifically, I've tried:
1) Opening one in imapviewer, merging the second. *crash*
2) Command line of the same thing, with the -nodisplay option. *crash*
3) Eric Boer's irrmap merge script. *crash*

If I had been smart, I would have simply calculated the first half of the animation at every 5th frame, and calculated the second half in the same way on the second computer. Instead, I split it up so that one computer was starting on frame 1 and calculating every 10th frame (frame 1, 10, 20, etc), and the other was starting on frame 5 and calculating every 10th (frame 5, 15, 25, etc).

The specs of the computers I've tried merging the two irrmaps on:

1) Dual 3.6 xeon, 2 gigs ram
2) Dual 2.8 Dualcore Xeon, 4 gigs ram

No luck on either. Anyone have a workaround? Sorry for the TMI post.

Thanks!

[cpnichols]

Re: Merging HUGE irradiance maps - is it possible?

Hi people,

I recently split the irradiance map calculation of a very complex interior animation with some quick camera pans between two machines overnight. The result was two irr maps at around 600 MBs each.

I have tried every method I can find to merge these two maps together, but nothing is working.
Specifically, I've tried:
1) Opening one in imapviewer, merging the second. *crash*
2) Command line of the same thing, with the -nodisplay option. *crash*
3) Eric Boer's irrmap merge script. *crash*

If I had been smart, I would have simply calculated the first half of the animation at every 5th frame, and calculated the second half in the same way on the second computer. Instead, I split it up so that one computer was starting on frame 1 and calculating every 10th frame (frame 1, 10, 20, etc), and the other was starting on frame 5 and calculating every 10th (frame 5, 15, 25, etc).

The specs of the computers I've tried merging the two irrmaps on:

1) Dual 3.6 xeon, 2 gigs ram
2) Dual 2.8 Dualcore Xeon, 4 gigs ram

No luck on either. Anyone have a workaround? Sorry for the TMI post.

Thanks!

That would be a huge problem... I also find it hard to believe that your would NEED your irradiance maps to be that big. How many frames is your animation? What res?

[emptyvoxel]

I think my problem is that there are a lot of brushed metal surfaces in the scene, all of which had trace reflections on. There are also several mirrors, and it seems like reflective surfaces make irmaps into monsters.
The animation is a mere 1500 frames, but the geometry itself is complex, coming in at around 3.5 million polys. It has all the details like hinges and latches modeled in, and all the parts are "build" geometry imported from CATIA. Also, almost all of the lighting is indirect, coming from coves or from behind valances.
I was at -3/0, 50/30 for my irmaps, but I think that I can get away with lower settings, and toning down the reflections should also help.

Thanks for responding, Chris. It looks like my problem is not merging the maps, but the fact that they're so large to begin with. One of these days I'll get around to watching your Global Illumination: Interiors DVD, which is in fact sitting on my desk right now.

~e

[cpnichols]

First off, you should not use the irradiance map for animations for reflections. Those need to be done brute force. Also even with a 1500 frame anim which is crazy long, I very rarely see an irradiance map bigger then 100 megs total. An insanly high quality Irradiance map that I saw was 190 megs. Sounds to me like you are using way to high a setting. keep the 50 subdiv, but do -3,-2... and if your anim is 1500 frames I bet it is pretty slow camera, so you can get away with doing the irradiance map every 30 frames. You are using incremental add to current map right?

[emptyvoxel]

Earlier today I turned my settings down and things are going a lot better. I was using multiframe incremental as suggested in the vray documentation, simply because I didn't have a map in memory.
I'm not clear on what you mean when you say "you should not use the irradiance map for animations for reflections." Do you mean I should globally turn off reflections before calculating the irradiance map, then back on at render time?

Thanks for your time!

[cpnichols]

Earlier today I turned my settings down and things are going a lot better. I was using multiframe incremental as suggested in the vray documentation, simply because I didn't have a map in memory.
I'm not clear on what you mean when you say "you should not use the irradiance map for animations for reflections." Do you mean I should globally turn off reflections before calculating the irradiance map, then back on at render time?

Thanks for your time!

What I mean is turn off the use interpolation thing in the materials.

[emptyvoxel]

What I mean is turn off the use interpolation thing in the materials.

Oh, okay. I have that turned off already, so I don't think it was the problem. I replaced most of the brushed metals with fake non-reflective materials and went with -3/-1. I ended up with a 250 mb irmap after rendering out every 8th frame (strange, I know, but after going over my camera path I decided I needed something between 5 and 10), and rendered out in something like 3 hours, a vast improvement from before.

So I'm still probably overdoing it a bit, but its manageable and will render overnight on our modest render farm. This is my first flythrough with vray, so having your help is very much appreciated.

Cheers!

[cpnichols]

What I mean is turn off the use interpolation thing in the materials.

Oh, okay. I have that turned off already, so I don't think it was the problem. I replaced most of the brushed metals with fake non-reflective materials and went with -3/-1. I ended up with a 250 mb irmap after rendering out every 8th frame (strange, I know, but after going over my camera path I decided I needed something between 5 and 10), and rendered out in something like 3 hours, a vast improvement from before.

So I'm still probably overdoing it a bit, but its manageable and will render overnight on our modest render farm. This is my first flythrough with vray, so having your help is very much appreciated.

Cheers!

I would do every 20 to 30 frames. You should be able to be fine. A IR map of around 30 to 50 megs is plenty. Over 200 starts to get un-managable. On My DVD, The one I did for that whole city was around 45 megs, and that was with a fast camera. Keep in mind that you can still spot render areas if they are undersampled and add them to your current map. Good for when you wip around a corner right in the middle of your 30 frame increment. Use the IR map viewer to see your results.

[emptyvoxel]

I think you're right, I could have gotten away with less frames and then just done 5-10 little "touch up" frames. Next time I will go about this a bit smarter, thanks in no small part to your help (and DVDs).

Thanks again!