ies ligths .....why?

[Eric Sosa]

we are making different test using IES ligths in our shop (interior design) 3d visus, yes, very real & technically precise profile ligths BUT....hell, it takes 3 times more to render then vray ligths and 8 times more then standard max ligths .

 

even tho we got 6 pc working with DR, render times using IES ligths are some kind of un-affordables and we are thinking about dropping the idea of using such precise ligths for our visus....pitty, I would say, I love the idea of giving our costumers a very realistic ligthning for their shops to be built.

 

is there any way to use IES ligths and spare render time?

 

vraysetups?.., don't know, we have optimised our vray setups to get the best & fastest visus according to quality vs render time.

 

thx for any help

[Thablanch]

I do not think that you should compare to standards lights, as they do not give the result

 

Have you tried the new vray IES, they are faster that regular IES with VrayShadows.

 

As well, you could use the ies near walls, to give that wanted scallop effect on the wall, and fill the balance of the space with more performant lighting.

 

I like .ies cause they are no work, effect is there, no foolin' around.

 

As well, (a few years ago) I found out that not all IES light have the same render time, guess it is how it is build, or the distribution.. whatever..

[Arnold Sher]

Hi Eric,

 

Common misconception that IES lights take long time to render is completely unfounded due to not understanding the proper set up in order to achieve the best result. All our interiors have Ies photometric lights in and it renders faster than vray or standard lights. Here is the trick that one needs to know in order speed things up. Your lights needs to have Shadow Map on as a shadow and the only light that you should use Vray Shadow on is the one closest to the camera and only if you want to have precise shadows because that is the only time you'll actually see it. If you do that you'll find your render times will improve dramatically while still retaining the quality. That should sort things out for you and let us know an improvement...Good luck...

[shaneis]

is there any way to use IES ligths and spare render time?

 

Try to be specific with your light-linking. I think the main reason is that IES lights tend to have a very wide angle of effect. Not so much the main beam, but the finer "bands" of light from the reflectors can spread to around 160deg or more. Once Final Gathering/ GI is introduced into the scene, those effects are quickly lost on all but the geometry in immediate proximity to the light. So if you can un-link geometry that is outside the main beam, you should save a bit of time

[Eric Sosa]

I do not think that you should compare to standards lights, as they do not give the result

 

Have you tried the new vray IES, they are faster that regular IES with VrayShadows.

 

As well, you could use the ies near walls, to give that wanted scallop effect on the wall, and fill the balance of the space with more performant lighting.

 

I like .ies cause they are no work, effect is there, no foolin' around.

 

As well, (a few years ago) I found out that not all IES light have the same render time, guess it is how it is build, or the distribution.. whatever..

@ alain; unfortunatelly we do not have the latest vray version in the company with the new vray ies ligths, besides I am not looking for anything fancy with scallops, etc, but realistic ligthning. thx for the tip anyway.

 

Hi Eric,

 

Common misconception that IES lights take long time to render is completely unfounded due to not understanding the proper set up in order to achieve the best result. All our interiors have Ies photometric lights in and it renders faster than vray or standard lights. Here is the trick that one needs to know in order speed things up. Your lights needs to have Shadow Map on as a shadow and the only light that you should use Vray Shadow on is the one closest to the camera and only if you want to have precise shadows because that is the only time you'll actually see it. If you do that you'll find your render times will improve dramatically while still retaining the quality. That should sort things out for you and let us know an improvement...Good luck...

hay arnold , thx for the tip, great help

 

indeed, if I use Shadow Map instead of vray shadows, the renders are ever so fast, mainly because of not using the vray shadows anylonger either with the ies ligths or standard max ligths/target spots. so speed is not a problem anymore.

 

Try to be specific with your light-linking. I think the main reason is that IES lights tend to have a very wide angle of effect. Not so much the main beam, but the finer "bands" of light from the reflectors can spread to around 160deg or more. Once Final Gathering/ GI is introduced into the scene, those effects are quickly lost on all but the geometry in immediate proximity to the light. So if you can un-link geometry that is outside the main beam, you should save a bit of time

 

hej shane ,

 

no need to avoid other geometry if we use, as I said about arnolds tip, Shadow Map. GI effects can be seen in the objects, mainly out of reach of the ligth beam, thx for the comment mate.

 

I made some fast test, wich I am very pleased with.

 

[ATTACH]29392[/ATTACH] [ATTACH]29394[/ATTACH] [ATTACH]29393[/ATTACH]

 

used only the ies ligths (no other ligth source including enviroment) with Shadow Map and an outdoor vray ligth simulating the mall ligth entering the shop, which has only a little effect in the displays placed at the front & facing the cam.

 

in the first pic u can see the 20w narrow spot burning the displays top glass. second pic, a 35w wide spot lightning smoother and wider. 3th pic, a very fast render (cam behind a glass in front of the shop) using the ies ligths with vray shadows...

 

dilema: vrayshadows are VERY precise compare to Shadow Map. you can see the ligth going through the glass and lightning the lower shelf of the display and ligthning also the spaces between the trays in the last pic. a compromise, as arnold mention of using a vrays shadow ONLY for the spot closest to the cam...dunno, the goal is clear...a very realistic ligth source.

 

last question: where to start when talking about realistic lighting?, the ies ligths gives JUST the rigth lumination, but what about the rest?...I mean, if I only use the ies ligths, floor and displays look nice but the upper part of the shop will remain very dark. I would add another ligth source to help lighning the upper part of the shop...but how much?

 

by experience we have seen this; the shop visualisations we make look often much ligther and nicer then the real shops (when finally builded)..and funny, some costumers notes this and comment it with us.

 

however, great figure this ies ligths, we certainly use them in the future., thx for your help guys

Edited October 8, 2008 by Eric Sosa

[shaneis]

no need to avoid other geometry if we use, as I said about arnolds tip, Shadow Map. GI effects can be seen in the objects, mainly out of reach of the ligth beam, thx for the comment mate.

 

I think you misunderstood me - what I meant was that once FG/GI are introduced into the scene, the fine banding and subtle IES effects are often lost.

 

dilema: vrayshadows are VERY precise compare to Shadow Map. you can see the ligth going through the glass and lightning the lower shelf of the display and ligthning also the spaces between the trays in the last pic. a compromise, as arnold mention of using a vrays shadow ONLY for the spot closest to the cam...dunno, the goal is clear...a very realistic ligth source.

 

Hmmm, I know....LIGHT-LINKING! If you want more precise control, use shadow-linking as well.

 

...I mean, if I only use the ies ligths, floor and displays look nice but the upper part of the shop will remain very dark. I would add another ligth source to help lighning the upper part of the shop...but how much?

 

by experience we have seen this; the shop visualisations we make look often much ligther and nicer then the real shops (when finally builded)..and funny, some costumers notes this and comment it with us.

 

I've done a few light studies for clients using IES to help them select the luminaire types and lamp wattages. If I find during the renders that there isn't enough illumination throughout the area, rather than increase my GI, I tell them "you're going to need either more lights, brighter lamps or a different type of light". Every single time they were glad to have that kind of information before they spent thousands and thousands on fittings and electrical work. Once they've made their changes, I re-render.

 

You could do the same with your current clients. It looks like a jewellery store, yes? Show them the tests, and ask if they would like to make some changes before they finalise the lighting. I guarantee they'll appreciate the advice.

 

Hope this helps,

 

S.

Edited October 8, 2008 by shaneis