Photon map problem

[zapcat]

I'm trying photon maps for the first time and am getting some wierd results as you can see from the image. I'm not sure what the correct term is for this sort of problem, but can anyone suggest how I can fix it?

Zap

[GoncaloP]

Better to not use photometric lights with photon mapping, the distribution of the IES is ignored.

Gonçalo

[dusan]

I tried using ies with photon mapping some tiime ago on an older version of vray and i think id didnt work... So how do you work with photons? only with direct computation?

[GoncaloP]

Dont understand what you mean... but I think the best way to work with ies files is with irradiance map, try to play with another Gamma value like 1.8 or 2.2 in max preferences, and choose the gamma that fits better to your needs.

This will increase the range in white values, to better see the effect, open the color selector and look at the gray scale with the default gamma 1.0, then increase it to 2.2 or so and you will see that black values are now in much less portion, and white values in other way around, the colors also tends to desaturate, this will control the excess of color bleeding that use to happen with this kind of interior images with irradiance map. Now you can play with color mapping with bright and dark multipliers to get the contrast you want...

Good luck,

Gonçalo

[dusan]

DONT EVER LEAVE THIS FORUM GONCALO!!!
please

and get icq

[Tony_Morev]

actually photometric lights work just fine with photon maps
all you got to do is set a higher diffuse multiplier in v-ray properties on those lights

as far as the corner artifacts, they most likely come from the wrong diffuse subdivision and photon maps settings

all of which has been described by Gonsalo on many occasions here

[particlerealities]

I'd like to know where you found those downlights. Are they Erco? Similar lights were used by another member of this forum, but they evidently can't speak english enough to answer my question.

[zapcat]

Particlerealities - go to this excellent tutorial by Natty http://www.chaoticdimension.com/foru...pic.php?t=3647 and scroll down. there's an option to download the IES data from there.

Zap

[Tony_Morev]

2zapcat:

the tutorial you gave a link to doesn't work with photon maps
try to set PM for both first and secondary bounces and you'll see for yourself

to get rid of the spots on your images you will have to raise the diffuse multipliers on your lights to get a reasonable (just a little noisy) picture in that mode

but you probably already figured it all out on your own

[zapcat]

Well I'm now back from two weeks in sunny Miami. If there any 3D jobs going out there let me know!! Fantastic place to live.

Anyway, I've played with the settings on this scene and here's the result. Still have some work to do, once I get the time.....



Any thoughts or comments, let me know.

Cheers.

Zap