irr map calculation for hi-res stills

[vermu]

Hi,

I am doing a hi-res still 3508*2480 and irr map calculation is taking very long. I am region rendering top and bottom half on different machines but it still takes very long time. Can you usually use lower res irr map with hi-res stills or are there any tricks to make irr map calculation work faster with hi-res pics?

[mmikee]

I usually render with high settings on a lower size. I then save the ir and
load it for the higher res render. It works fine for me. As far as tips for
speeding up the calculation, there are alot of people on this forum
with more vray mojo than me.

[vermu]

How much lower can you you go with your irr map. What resolution do you use if you render for example 3508*2480? I just tried to render my irr map at full res but I guess something went wrong cause irr map wasn't complete and render went haywire.

[vermu]

I am just trying to render 2000*1414 with high settings and then use that irr map for 3508*2480 render. It's been now stuck in prepass 4 of 4 for ages. There's loads of memory that is unused but I guess it takes just computing power.

[Clifton Santiago]

If you calculate an IR map at 4000x2000 with min/max of say-4,-2, it will be the same as rendering at 2000x1000 at -3,-1. In other words, you can render half-size, but if you want the same quality as full size, you need to add 1 to each min/max value. So its a wash... each takes about the same time to calculate.

You are probably having memory problems. Enable dynamic memory and and turn it up as high as you can without crashing max. If you are rendering to a frame buffer make you buckets much smaller. If you are on a 32bit OS, enable the 3gb switch.

Rather than render regions on two machines try rendering strips in backburner. If you are doing daytime exteriors with IR/QMC you don't usually need to precalc the IR map. Just send the stripes and let each machine calculate the IR for that strip, which takes much less memory than doing the whole thing.