Precalculated IRR-map and LC

[obeth]

I have a couple questions regarding precalc. IRRmaps and LC for animations and the settings needed in the MAX common rendersettings.

1. When making a precalculated IRRmap, is it necessary to output to a render files (f.ex. TGA or PNG) under the MAX common rendersettings?

2. When precalculating a LC with the settings on flythrough does it matter what the settings are on in the MAX common rendersettings? I know that the range of frames is needed but what about the Nth frame setting. Do all frames get calculated regardless of the Nth setting or what? And again, do I need to output to render files?

3. I have read several posts about merging IRRmaps. Last night I started a precalc.IRR map via Backburner and I must have goofed up somehow. It seems I assigned the job to all servers and not one specific machine so now some of frames in the IRRmap are from one rendernode and some from others. Is the resulting IRRmap going to work (when it gets finished) or should I just stop it now and start it over on one node as I had intended to?

Thanks for any input.

[DanielBrew]

Hi Obeth,

1. No you don't need to render an image when calculating IR maps. There is a switch under global switches 'Don't render final image' for this purpose.

2. No, I don't think nth frame setting makes any difference. The samples (no. of samples=subdivs^2) are distributed randomly along the camera path for the range of frames. Again you don't need to render a final image.

3. I don't think it's going to work. You can split the calculation but you'd be better sending frames 0-200 to server 1, frames 201-400 to server 2 etc. then combining the IR maps with IR map viewer. There might be a script to help with this. In the future you will be able to precalc using DR but I don't think it's in 1.47.03.

Dan

[obeth]

Hi Dan,

Thanks for the answer.

1 : I thought that if I checked the don't render final image it would overrule any render output save settings in the MAX common settings. That isn't the case however. You'll just get a bunch of ima1ges of your LC/irr_map.

3 : I've stopped it and started it over again on a single node --- bummer

[DanielBrew]

1: Yes sorry, you still have to uncheck 'save file' in common. It will still use the resolution specified in common for the IR map size though.

Dan

[cristoforo]

How do you save the individual IR calculation that goes to each node? Normally, when doing the IR calculation on just one computer, when it is finished I click on the "save to file" under the IR map drop down. If this is sent to another computer through backburner, as soon as it finishes Max closes on that node, so there is not the possibility to click "save to file." In addition, working this way do I use multiframe incremental or incremental add?

[DanielBrew]

Hi Cristoforo,

At the bottom of the 'Irrariance map' roll up there is a section 'On render end'. You can tell VRay to Autosave the irradiance map when the calculation has finished.

You should set the mode to 'multiframe incremental' for this method so it clears the memory before starting the calculation.

Does this help?

Dan

[cristoforo]

Thanks Dan. I'll check that out. Another question...In any given part of an animation are only the lights that are actually seen in that moment considered for the calculation, or whether seen or not are all lights calculated? In one segment of my animation I am in the waiting room and then pass through a hall, then arrive to an overlook of the main open working space (full of lights). For the calculation of the IR map, should I have the lights off in the open space when I am calculating the beginning part of the animation to make the calculation quicker? I hope my question is clear? I'm doing this calculation now on one computer, which has been going already for 26 hours and tells me that it still has 44 hours to go! This is only for 480 frames. I'm thinking now that I should break it up among three computers to make it quicker.

[DanielBrew]

Your question is clear enough, I'm just not sure of the answer .

I think VRay takes all the lights into account when it starts the calculation but I know from experience that VRay is also very good at disregarding lights that do not have an impact on the final image. So turning them off might not make the calculation any quicker.

If you think the lights in the main working space will make little or no difference to lighting of the first part of the animation then there can be no harm in turning them off. It can't make it any slower. Also try hiding any geometry which cannot be seen. That is the other advantage of breaking down the calculation.

Your IR map calculation shouldn't be taking 70 hours for 480 frames though. What have you set 'nth frame' to in 'common parameters?

[DanielBrew]

ven't done already, you should read http://www.spot3d.com/vray/help/VRay...ials_imap2.htm

Dan

[cristoforo]

Yep...have that tutorial printed and in front of me! I also thought 70 hours was awefully long for 480 frames! Though, I thought that maybe it is so long due to all the lights in the scene. I am calculating every 10th frame. For settings of IR map I am using the medium setting, Hsph subdivs 40, Interp. samples 20, Interpolation type - least squares fit, Sample look up - density based. I'm using a saved LC. More or less the light set up is as follows: (maybe a screen shot would help)

[DanielBrew]

Yes, there are quite a lot of lights but I still don't think it should be taking 70 hours. The scene I'm working on here has 2.5m polys, 216 lights and I'm able to render stills using IR+LC at 4000x2000 in 2 - 4 hours.

If you're going to split the calculation of the IR map down you should try one not using the saved LC. Just to see if that is causing the long calc times. How many samples have you set in the saved LC?

[cristoforo]

Apparently there were two problems...I was using interpolated glossies which seems to be a no no for animations.....also causing long IRR calculations...and I was just using lots of glossies! I turned off the interpolation and reduced glossies from ,75 to ,90. I did the IRR calculation in 4 hours! Much better. Though, now it is taking from 30 to 45 minutes to render each frame. A bit nervous here!