# hair Material not working with light select pass? **URL:** \ **Category:** Issues\ **Created:** [September 23, 2013, 11:54pm UTC](https://forums.chaos.com/t/hair-material-not-working-with-light-select-pass/46418 "2013-09-23T23:54:19Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![sharktacos](https://avatars.discourse-cdn.com/v4/letter/s/f0a364/32.png) [@sharktacos](https://forums.chaos.com/u/sharktacos)\ **Post date:** [September 23, 2013, 11:54pm UTC](https://forums.chaos.com/t/hair-material-not-working-with-light-select-pass/46418/1 "2013-09-23T23:54:19Z")
The vrayHairMtl3 does not show up in a light select pass when it is set to diffuse. It is just black, regardless of what the material’s diffuse color or amount is set to. Is this a known bug? Is there a workaround? ---
**Author:** ![svetlozar.draganov](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/svetlozar.draganov/32/53004_2.png) [@svetlozar.draganov](https://forums.chaos.com/u/svetlozar.draganov)\ **Post date:** [September 25, 2013, 10:41am UTC](https://forums.chaos.com/t/hair-material-not-working-with-light-select-pass/46418/2 "2013-09-25T10:41:03Z")
Thank you very much for your feedback - I got the same result here , it seams that this is not supported yet. I’ll make a note about it into our system and I’ll inform you when we have some progress in that direction. Meanwhile you could get Light Select Diffuse pass for the hair by: 1.Extracting Light Select Raw Pass 2.Extracting normal Diffuse Render Element (not from Light Select element) 3.Multiply those two images - and this should give you Light Select Diffuse Pass ---
**Author:** ![sharktacos](https://avatars.discourse-cdn.com/v4/letter/s/f0a364/32.png) [@sharktacos](https://forums.chaos.com/u/sharktacos)\ **Post date:** [September 25, 2013, 5:11pm UTC](https://forums.chaos.com/t/hair-material-not-working-with-light-select-pass/46418/3 "2013-09-25T17:11:46Z")
> [@svetlozar\_draganov](#): > > Thank you very much for your feedback - I got the same result here , it seams that this is not supported yet. > I’ll make a note about it into our system and I’ll inform you when we have some progress in that direction. > > Meanwhile you could get Light Select Diffuse pass for the hair by: > > 1.Extracting Light Select Raw Pass > 2.Extracting normal Diffuse Render Element (not from Light Select element) > 3.Multiply those two images - and this should give you Light Select Diffuse Pass There are two difficulties with this method: 1) **In general:** The above method (diffuse \* LightSelectRaw = LightSelectDiffuse) produces artifacts in comp (This is known issue that affects vray in general. I have an explanation of it along with a workaround [here](http://sharktacos.com/Forums/misc.php?action=help&hid=20)) 2) **Specific to the hair material:** The passes do not add up to equal the beauty with this method. This is because the spec pass produced by the hair material appears to contain both spec and diffuse light. The hair is currently outputs so that reflect + refract + spec + GI = beauty. What is of course missing here is the diffuse light contribution. This would indicate to me that the diffuse light is _included_ in the spec pass for the hair material. That is would explain why it does not show up in the LightSelect diffuse pass. What we are currently doing as a workaround is adding the light select spec for the hair to the lightSelect diffuse. ---
**Author:** ![svetlozar.draganov](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/svetlozar.draganov/32/53004_2.png) [@svetlozar.draganov](https://forums.chaos.com/u/svetlozar.draganov)\ **Post date:** [October 1, 2013, 7:21am UTC](https://forums.chaos.com/t/hair-material-not-working-with-light-select-pass/46418/4 "2013-10-01T07:21:10Z")
You are right specular pass contains also diffuse information - I have added a note about it into our system. We are glad to hear that you have found a workaround to this issue - we will update you as soon as we have a solution.