Light map Vs. QMC

[BBullo]

In the past I've been using 1st bounce irr map 2nd lightcaching
I often do this to set up lighting in a scene on a standalone machine.
I would like to switch over to -1st Irr map 2nd QMC to send this over a network rendering.
The thing I've noticed is that when I switch from LC to QMC, the lighting totally changes. The image becomes dark.
I adjust this by going into QMC GI and increasing the secondary bounces.

My question is this, is there a way to find the sweet spot on the secondary bounces? If I go from 3 to 50 it dumps alot of light into the scene, and looks very similar to the LC amount of light. If I take that up 500 it takes a little longer and looks no different than 50.

Does any one else switch from LC to QMC?
If so would you care to share your workflow?

thanks.

[Moose]

I would like to switch over to -1st Irr map 2nd QMC to send this over a network rendering

i might be misunderstanding your scene requirements but why cant you use the LC on the network?

[joconnell]

Heya B Bullo - The reason it doesnt make much difference from 50 to 500 is that unless everything in your scene is perfectly white, the light will lose some brightness every time it hits off an object so the more bounces the light does, the less intense its effect until eventually you don't see much of a difference. I think somewhere between 10 to 20 should do it for interiors and around 3 should be fine for exteriors. Personally I do a lot of animation work so I can't really use irradiance mapping or light cache for the first bounce since the animation means each frame is very different so irradiance mapping or light cache would flicker. In the secondary bounces this is a lot less of a problem so I tend to use qmc for my first bounce and lc after that.

What type of scenes are you rendering?

[3ddesign]

I would like to switch over to -1st Irr map 2nd QMC to send this over a network rendering

i might be misunderstanding your scene requirements but why cant you use the LC on the network?

B Bullo supplied me a scene that was 1st Irr and 2nd Lc that he rendered on a single computer. Due to crunch time, he gave it to me to render on my render farm. Other than the fact that Viz crashed everytime it tried to write the Irr map, it also took substancially longer to render than when I set it up as 1st Irr, 2nd QMC. But the switch requires re-setting up the lighting which is a pain.

Craig

PS Bret, I found that the scene won't crash at 800 x 600 but will at 1024 x 768. I'll try to test it further when I have time.

[BBullo]

joconnell, the scene I was talking about was an interior Still shot with large opacity maps glossy ref etc...rendered at 2400x1800.

I will have to experiment more with the QMC bounces.

I was just trying to find a clean way of going from one setup to the other.(LC to QMC as secondary). I think I can do it by adjusting the bounces for QMC GI. I just need to make sure that I give it enough bounces for the given scene, otherwise it renders out too dark.

[meanadam]

I am trying to find out a last min answer - that maybe one of you figured out now. Can you use QMC 2nd bounce over a DR render?

I think that is what this post is about.

At it would then be way faster than 1 machine doing a LC?

[BBullo]

Yes, you can.
It is usually faster, but it could depend on the number of machines you have set up on DR.