ies / transmat / parti_volume setup - possible in 2011?

[Dan Yargici]

I have a bunch of lights that are using ies profiles (using wom_archlight instead of mia_photometric_light because I need to turn off shadows on some of them...).  I am also using the mia_exposure_photographic lens shader.

Now I need to make these lights volumetric!

I discovered this post by lard on xsibase (about half way down) where he is using the parti_volume shader with a transmat shader on the surface port via the tek2shoot unexposed MI shader pack.  I'd like to do the same however, while I can find the parti_volume shader in 2011 and set it up using values from the documentation, the transmat shader is not there.  I tried with an architectural shader with cutout_opacity set to 0 in it's absence but it didn't seem to work.

I can't get the tek2shoot shaders as the site is down and I'm on Linux in any case.  Also, my understanding is that all these thing should be exposed by default now in 2011 so I'm wondering the transmat shader is actually there, just with some cryptic name?

Anyone managed this?

Thanks,

DAN

[Robert Chapman]

Hi Dan, it shouldn't matter what you have plugged into the material slot, and not sure about the IES lights, but works fine here with a phong plugged in with diffuse,spec, reflection & shadow disabled but transparency set to 1

[Dan Yargici]

Hi Rob.

Strange, I can't for the life of me get this working...  I've attached an image of what I'm seeing.  I've tried all kinds of settings on the parti_vol shader, what you see in the image is just how I happened to leave them.  The material has nothing plugged into it's surface port, when when I did as you suggested (transparent phong) I got the same result as this in any case.

Would you mind emailing me your test scene off-list if you have a spare 5 minutes so I can check if it's something screwy with my installation.

Thanks,

DAN

[Robert Chapman]

Hey , no worries , Ive attached a simple model and a screenshot,  the parti_volume is a bit of a pain in the ass, if you render with the settings as they arrive = long freeze and have to hard restart, some of the default settings at 0, MR is not happy with. Also there is a big difference between spot lights and point lights for sensitivity and you will need much lower numbers = more effect for the extinction parameter, like 0.001 for spotlights etc.  anyways hope this helps get you started.

Rob

[Dan Yargici]

Thanks Rob, it was the insanely small extinction that did it.

DAN

[Dan Yargici]

Now suppose I need hundreds of them and would like to use ice-instanced lights because I'm not a masochist and don't want a volume shader with a list of 1000 lights...... doh!

There's always a snag isn't there...

DAN

[Robert Chapman]

heheh well yes, it doesnt accept groups but if its any consolation the commands are logged so it does like adding lights is scriptable in a loop , so not as painful.

best

Rob