Different IR map on DR vs. non-DR??

[dlparisi]

I've been trying to use DR lately to speed up calculations of stills and am running into strange problems with the irradiance map calculations. Specifically, it looks as though there are some big differences between the IR map created by DR vs non DR renderings. See below...

The non DR version....


The DR version...


These two images are rendered with the "don't render final image" checked so its just the GI samples were looking at. My first thought was it has something to do with the DR machines (i.e. missing maps, plug-ins, etc) but I get the SAME problem if I leave DR checked but don't send it to any other machines except the local one (a dual opteron so I get two buckets). I've highlighted some of the areas where the DR map created is very different from the non-DR map although if you look closely you can see the edges of nearly all of the buckets.

So what's going on? Am I missing something or is this just a limitation of DR? Is this normal and/or expected and basically it should get smoothed out in the final image (it seems as though I can still see some of these "edges" in the final rendering).

BTW: I'm not sure if this is version related but I'm on Max 9 (32 bit), VRAY 1.5 RC4 (not sure if this happens in RC3).

[RErender]

If you do another one either locally or with DR does it match the first one rendered that way? There is a certain amount of randomosity involved, that is why frames rendered with Imaps will flicker.

[dlparisi]

Eric, I'm not sure what you're asking for vs. what I've already shown - the two images I posted are one done locally with no DR and one done through DR. I understand that there will be some differences in the actual samples, I'm not expecting them to line up sample for sample. My concern is with the hard edges to the number of samples taken in the DR version Mostly obvious along the vertial edge of the fireplace). These divisions line up with the edges of the DR buckets sent to different cores/machines.

[RErender]

yeah, now that you point it out those are in a pretty straight line

[jow]

Ive noticed the same using RC3. I put it down to what most ppl say, Dont DR the IR map, do it locally...
And where these lines are you get bad blotches in the render.
The only fix I found was to pump the IR map settings up to something like the very high preset.

[Da_elf]

you forgot the straight line over the door on the left too. ive never actually noticed this since i dont care what my samples look like as long as the final image is good and its usually always good. cant say ive ever noticed any mess ups or anything due to useing DR and i use it enough