50+ ies lights

[mikeh]

This is my first interior in years. I had used Lightsacpe a long time ago but abndoned it because it was so slow. Now i am giving Vray a shot for an interior lobby with over 50 lights that all have IES files.

My question is this: How do people go in to render test a scene when the render takes multiple hours? there is no way i can render, wait forever, tweak, re-render, wait forever, tweak etc and i am guessing that people doing interiors with vray don't do that either so any advice would be helpful.
Thanks.
mh

[percydaman]

mess with the qmc settings so you get a quick render. For testing purposes, I frequently use the following:

High Irrad map preset
QMC noise threshold .98 - 1.0
adaptive amount .2-.3

Play with the settings further. This roughly gives me a decent enough render thats quick and isn't too incredibly noisy.

[travistlo]

You can also get your lighting correct by using all grey materials first. This will give a good generalization of overall lighting. Then you can save the irr map and the LC for material test renderings and whatever. Then do final tweeking at the end using small regions instead of the full view.

[tom schuelke]

Yes, there are also other optimisations possible.

What is a big time factor , is that you use ies files. In some cases, it isnt nessesair, to use them.

for getting nice light patterns, if this is your aim, you can use a projectionmap, with a gradient ramp in your light projectionslot, to get comparable results in much less time.

well if it´s nessesair to use ies, ... ies is slow.

otherwise also use render region, and like told low general qmc settings, disabling reflections in the gernerals settings maybe, grey override material.

good luck.

Tom

[Candelero]

From my personal experience, I have found that the IES lights get extremely slow with the shadows. So far, I only use them with < Shadow map > type.
Keep in mind that this shadow, doesn't take into consideration the materials, it just reacts on geometry.


Best regards,
nikki Candelero

[thablanch]

well if it´s nessesair to use ies, ... ies is slow.

Some IES files renders faster than other, I do no know if that is the way they are buildt, but some of them can be as fast as a standard light

From my personal experience, I have found that the IES lights get extremely slow with the shadows. So far, I only use them with < Shadow map > type.

You can achieve acceptable results with Vray shadows, but without area shadows click, so crisp shadows, but quite fast. As you have 50+ of them, the light beams could interfeer together, and the result still be ok.

[mikeh]

thanks for all the feedback.
What i have encountered is this.
1. Vray renders the IES lights incorrectly. They render as if there is something physically blocking off part of the light. (mental ray has no problem with them.)
2. vray does not render instanced IES lights. When i have 6 lights all instanced from one light, Vray only renders one of theose lights. (Mental Ray has no problem with all of them)
3. Vray does not render photometric lights that are not IES. (Mental ray has no problem with them.)

So, i have to wonder if there is some switch in amongst the million or so switches in Vray that i am not hitting or is this just the way it is.
I am using Vray version Adv 1.46.15.
mh

[percydaman]

have you tried more then one ies file? can you share the one thats not working for you?

[mikeh]

It has a couple ies files (same results for both) and i do not know how to upload files...not sure if one can in this forum.
mh

[percydaman]

i just tried a test with an IES file that comes with max 8. had no problems instancing it. Nor did it have any occlusion looking problems.

[mikeh]

what happens when it gets instanced?
mh

[percydaman]

okay trying another ies light, i came across your occlusion looking problem. It seemed to resolve itself after I rotated it 90 degrees.

[percydaman]

no problems whatsoever with instances. They all show up just fine. I'm also using 1.47.03

[mikeh]

I'll try rotating...have no idea why instanced don't work...
Also it appears that "light Lister" does not recognize Vray lights. I started another test scene, popped in a vray light, instanced it around added another vray light, opened up light Lister and none where there.
mh

[percydaman]

No, I dont think the light lister currently does show vraylights. One large reason I rarely use it. People have posted scripts that work similiarly on the forum.