# vraylight MATERIAL and irradiance map **URL:** \ **Category:** General\ **Created:** [September 16, 2007, 8:18am UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683 "2007-09-16T08:18:31Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![pailhead](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/pailhead/32/18667_2.png) [@pailhead](https://forums.chaos.com/u/pailhead)\ **Post date:** [September 16, 2007, 8:18am UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/1 "2007-09-16T08:18:31Z")
I’m trying to simulate narrow linear light fixtures, hidden in coves, using vraylight **MATERIAL**. Brute force method requires a lot of samples to get any results, and no matter how high i go it’s still noisy. Irradiance map on the other hand is really splotchy and blurry, and has random light rays flying all over the place. I’m not really sure how to tell vray to take more samples when doing the irradiance map… any tips? **sorry for the confusion, i forgot to write “material”** ---
**Author:** ![vlado](https://avatars.discourse-cdn.com/v4/letter/v/779978/32.png) [@vlado](https://forums.chaos.com/u/vlado)\ **Post date:** [September 16, 2007, 9:09am UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/2 "2007-09-16T09:09:36Z")
You can do this with light portals; they do just that - direct V-Ray where to place more GI samples. Best regards, Vlado ---
**Author:** ![pailhead](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/pailhead/32/18667_2.png) [@pailhead](https://forums.chaos.com/u/pailhead)\ **Post date:** [September 16, 2007, 9:22am UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/3 "2007-09-16T09:22:09Z")
Light… portals? 😅 ---
**Author:** ![ene.xis](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/ene.xis/32/61710_2.png) [@ene.xis](https://forums.chaos.com/u/ene.xis)\ **Post date:** [September 16, 2007, 9:40am UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/4 "2007-09-16T09:40:02Z")
light portal=vray light set to skylight portal by the way vlado, what is the simple option for? ---
**Author:** ![vlado](https://avatars.discourse-cdn.com/v4/letter/v/779978/32.png) [@vlado](https://forums.chaos.com/u/vlado)\ **Post date:** [September 16, 2007, 9:44am UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/5 "2007-09-16T09:44:54Z")
> [@ene.xis](#): > > by the way vlado, what is the simple option for? Well, normally, with this option _off_ (the default), the light gets its color from whatever part of the scene is behind it (it sort of propagates light from one side of the light object to the other); however often the light is used at windows, where there is nothing behind it. In this special case, it is a waste of time to look at what’s behind the light, as we know that there is nothing of interest. So you can turn _on_ the **Simple** option and the light will always assume that only the environment is behind it, which will make the rendering faster. Best regards, Vlado ---
**Author:** ![ene.xis](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/ene.xis/32/61710_2.png) [@ene.xis](https://forums.chaos.com/u/ene.xis)\ **Post date:** [September 16, 2007, 9:57am UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/6 "2007-09-16T09:57:10Z")
🙂 that is handy little check box then aint it? :lol: thanx for the quick “enlightment”! 😉 ---
**Author:** ![pailhead](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/pailhead/32/18667_2.png) [@pailhead](https://forums.chaos.com/u/pailhead)\ **Post date:** [September 16, 2007, 6:37pm UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/7 "2007-09-16T18:37:16Z")
Darn! Sorry for the confusion, it was very late last night. I meant to write vraylight material, not vray light, that’s why i was confused by the portal thing. 😅 ---
**Author:** ![pailhead](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/pailhead/32/18667_2.png) [@pailhead](https://forums.chaos.com/u/pailhead)\ **Post date:** [September 23, 2007, 11:22pm UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/8 "2007-09-23T23:22:37Z")
So? Can someone answer me now that I’ve straighten my thougts 🙂 I raised the hsphere value to 150 and above, and kept the samples at half that value. I also had to reduce the dmc adaptive value to .7 and even lower, i was under the impression that this helped, because at 1.0 i would hardly get any samples at all. What is the proper way of getting enough samples from the vraylight material? ---
**Author:** ![ene.xis](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/ene.xis/32/61710_2.png) [@ene.xis](https://forums.chaos.com/u/ene.xis)\ **Post date:** [September 24, 2007, 8:45am UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/9 "2007-09-24T08:45:35Z")
> [@vlado](#): > > You can do this with light portals; they do just that - direct V-Ray where to place more GI samples. > > Best regards, > Vlado ---
**Author:** ![Shimakaze](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/shimakaze/32/34860_2.png) [@Shimakaze](https://forums.chaos.com/u/Shimakaze)\ **Post date:** [September 24, 2007, 8:53am UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/10 "2007-09-24T08:53:27Z")
Just to add to the confusion: Light Portals! 😄 [http://www.chaosgroup.com/forum/phpBB2/viewtopic.php?t=19753](http://www.chaosgroup.com/forum/phpBB2/viewtopic.php?t=19753) ---
**Author:** ![ene.xis](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/ene.xis/32/61710_2.png) [@ene.xis](https://forums.chaos.com/u/ene.xis)\ **Post date:** [September 24, 2007, 9:44am UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/11 "2007-09-24T09:44:17Z")
just get one or more vraylight(light portals on) near or around ur self iluminated material (vraylight mat), this way vray knows where to look for those samples! 😉 ---
**Author:** ![pailhead](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/pailhead/32/18667_2.png) [@pailhead](https://forums.chaos.com/u/pailhead)\ **Post date:** [September 24, 2007, 8:39pm UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/12 "2007-09-24T20:39:59Z")
The problem is, my vraylight material is on a really narrow circular path that is hidden in a cove and follows a curved wall. I would have to use 100s of small square vray lights to achieve this effect. ---
**Author:** ![ene.xis](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/ene.xis/32/61710_2.png) [@ene.xis](https://forums.chaos.com/u/ene.xis)\ **Post date:** [September 24, 2007, 9:36pm UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/13 "2007-09-24T21:36:54Z")
yep…i fell ur pain!i ve been in the same situation a couple of times… ☹ i ve found a usefull script to distrubute tiny vraylights form me nevertheless… i ll dig it up if ur interested. 🙂 ---
**Author:** ![pailhead](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/pailhead/32/18667_2.png) [@pailhead](https://forums.chaos.com/u/pailhead)\ **Post date:** [September 24, 2007, 10:14pm UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/14 "2007-09-24T22:14:37Z")
I sure am, if you can do that i’d be grateful. But i’d still like to know what’s the proper way to get more samples from the light mat. ---
**Author:** ![ene.xis](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/ene.xis/32/61710_2.png) [@ene.xis](https://forums.chaos.com/u/ene.xis)\ **Post date:** [September 24, 2007, 10:41pm UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/15 "2007-09-24T22:41:54Z")
this **is** “propper” way atm…i m still patiently awaiting for vray s geometry lights! 😉 i m looking for the script right now! ---
**Author:** ![deneb26](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/deneb26/32/32397_2.png) [@deneb26](https://forums.chaos.com/u/deneb26)\ **Post date:** [September 26, 2007, 5:20pm UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/16 "2007-09-26T17:20:32Z")
hi i’m doing a bistro/lounge scene and i use a plenty of varylight-materials for lighting it. in fact there’s only light from the geometry and some slight vray-skylight. no splotches no leaks or fireflys. don’t no why not, as i recently did an interior with a tv on (vraylight-mat) and it produced many splotches. i will show the pic soon. cya. ---
**Author:** ![MoonDoggie](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/moondoggie/32/68517_2.png) [@MoonDoggie](https://forums.chaos.com/u/MoonDoggie)\ **Post date:** [September 26, 2007, 7:31pm UTC](https://forums.chaos.com/t/vraylight-material-and-irradiance-map/15683/17 "2007-09-26T19:31:15Z")
does the vraylight set to portal have to be fully encompassing the entire place you don’t want it to produce sploches or just the light, ie, if I have an uplight around a ceiling, does the vraylight need to go over a piece of the ceiling from the camera’s view or just above the vraylightmat?