# RT always darker **URL:** \ **Category:** Issues\ **Created:** [June 18, 2014, 8:50am UTC](https://forums.chaos.com/t/rt-always-darker/50201 "2014-06-18T08:50:30Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![KiboOst](https://avatars.discourse-cdn.com/v4/letter/k/c0e974/32.png) [@KiboOst](https://forums.chaos.com/u/KiboOst)\ **Post date:** [June 18, 2014, 8:50am UTC](https://forums.chaos.com/t/rt-always-darker/50201/1 "2014-06-18T08:50:30Z")
Hi, We have just switch from 2.40.04 to 3.00.07 and while previously we had no problem with RT (cpu), now we can’t get rt to reflect render result. It is always darker. No subpixel mapping max or vray camera, the same increased rt gi bounces to 100 etc etc change nothing tried vray VFB with icc profil, worst Here is a very simple scene, an hdr on a vraylight dome + vraylight, showing the result. ![RT30007.jpg](https://europe1.discourse-cdn.com/chaosprd/original/3X/3/b/3b32f66c69b39b59ca2d2b3f0fae712340535ec1.jpeg) ---
**Author:** ![yolov](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/yolov/32/11920_2.png) [@yolov](https://forums.chaos.com/u/yolov)\ **Post date:** [June 18, 2014, 9:21am UTC](https://forums.chaos.com/t/rt-always-darker/50201/2 "2014-06-18T09:21:05Z")
Are you trygin to match the production renderer to RT? Or both results come from RT but from different versions? If you’re comparing to the production renderer - what’s your GI solution there? ---
**Author:** ![KiboOst](https://avatars.discourse-cdn.com/v4/letter/k/c0e974/32.png) [@KiboOst](https://forums.chaos.com/u/KiboOst)\ **Post date:** [June 18, 2014, 9:33am UTC](https://forums.chaos.com/t/rt-always-darker/50201/3 "2014-06-18T09:33:07Z")
RT on the left, production on the right. RT should be like production. GI : Irradiance/Lightcache linear setup 3dsmax 2014 sp3, win7pro x64, vray 3.00.07 ---
**Author:** ![yolov](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/yolov/32/11920_2.png) [@yolov](https://forums.chaos.com/u/yolov)\ **Post date:** [June 18, 2014, 11:44am UTC](https://forums.chaos.com/t/rt-always-darker/50201/4 "2014-06-18T11:44:18Z")
I was going to say it’s the GI (RT will always render BF+BF) but it might be something else that’s not supported. Can you get us the scene? ---
**Author:** ![KiboOst](https://avatars.discourse-cdn.com/v4/letter/k/c0e974/32.png) [@KiboOst](https://forums.chaos.com/u/KiboOst)\ **Post date:** [June 18, 2014, 12:46pm UTC](https://forums.chaos.com/t/rt-always-darker/50201/5 "2014-06-18T12:46:08Z")
I’ve test BF/BF in production and lighting is exactly the same. Here is the scene : [www.kreaction.com/temp/VRay3](http://www.kreaction.com/temp/VRay3)\_RT\_01.zip ---
**Author:** ![yolov](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/yolov/32/11920_2.png) [@yolov](https://forums.chaos.com/u/yolov)\ **Post date:** [June 18, 2014, 12:58pm UTC](https://forums.chaos.com/t/rt-always-darker/50201/6 "2014-06-18T12:58:01Z")
You mean that you still get the difference after switching to BF/BF? I’ll take a look at the scene right away. Thanks. ---
**Author:** ![matanov](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/matanov/32/21656_2.png) [@matanov](https://forums.chaos.com/u/matanov)\ **Post date:** [June 18, 2014, 1:40pm UTC](https://forums.chaos.com/t/rt-always-darker/50201/7 "2014-06-18T13:40:31Z")
Apparently this particular VRaySun is bugged. The RT image is darker because the sun is not affecting anything. Try creating a new one with the same properties and everything will be ok. Maybe the problem is that the sun is created in 2.4 ? ---
**Author:** ![KiboOst](https://avatars.discourse-cdn.com/v4/letter/k/c0e974/32.png) [@KiboOst](https://forums.chaos.com/u/KiboOst)\ **Post date:** [June 18, 2014, 2:06pm UTC](https://forums.chaos.com/t/rt-always-darker/50201/8 "2014-06-18T14:06:11Z")
Strange, this scene was entirely created in VRay3. Have created a new one and got the same now. Also, something that seems a bug, not happening in production but in RT : - Create a dome light, put a VRayHDRI on it - check lock to orietation on the dome - turn the dome : the map turn, as show RT - create a VRaysun - link the Vray sun to the dome, so rotating the dome rotate the sun : the map doesn’t rotate anymore on the dome … ---
**Author:** ![matanov](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/matanov/32/21656_2.png) [@matanov](https://forums.chaos.com/u/matanov)\ **Post date:** [June 18, 2014, 2:56pm UTC](https://forums.chaos.com/t/rt-always-darker/50201/9 "2014-06-18T14:56:12Z")
> [@vray lens effects aperture shapes](https://forums.chaos.com/t/vray-lens-effects-aperture-shapes/45212/2): > > Strange, this scene was entirely created in VRay3. Have created a new one and got the same now. > > Also, something that seems a bug, not happening in production but in RT : > - Create a dome light, put a VRayHDRI on it > - check lock to orietation on the dome > - turn the dome : the map turn, as show RT > - create a VRaysun > - link the Vray sun to the dome, so rotating the dome rotate the sun : the map doesn’t rotate anymore on the dome … Pffff while trying to reproduce this - I came right into the other issue. The sun is not working properly in RT when it’s linked … It’s an old issue … ---
**Author:** ![KiboOst](https://avatars.discourse-cdn.com/v4/letter/k/c0e974/32.png) [@KiboOst](https://forums.chaos.com/u/KiboOst)\ **Post date:** [June 18, 2014, 3:24pm UTC](https://forums.chaos.com/t/rt-always-darker/50201/10 "2014-06-18T15:24:19Z")
If we put a point dummy inside, it works ! center and link ome to dummy center and link sun target to dummy link sun to dummy Now it works ! ---
**Author:** ![dsolod](https://avatars.discourse-cdn.com/v4/letter/d/eada6e/32.png) [@dsolod](https://forums.chaos.com/u/dsolod)\ **Post date:** [June 19, 2014, 3:05am UTC](https://forums.chaos.com/t/rt-always-darker/50201/11 "2014-06-19T03:05:49Z")
Sorry, We are having the same issue with 3ds Max 2014 and VRay 3.00.07 RT CPU The simple scene with VRay plane and VRay material and VRay Sun was created in VRay 3. Sun was changed into StandardVRay Light with no success. ![VRay 3 RT.jpg](https://europe1.discourse-cdn.com/chaosprd/original/3X/1/0/1083905bc54736bda9dd993d55cf7e4194215c2e.jpeg) ---
**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:** [June 19, 2014, 8:50am UTC](https://forums.chaos.com/t/rt-always-darker/50201/12 "2014-06-19T08:50:55Z")
Would it be possible to send us the scene for investigation? Thank you very much in advance. ---
**Author:** ![dsolod](https://avatars.discourse-cdn.com/v4/letter/d/eada6e/32.png) [@dsolod](https://forums.chaos.com/u/dsolod)\ **Post date:** [June 19, 2014, 9:30am UTC](https://forums.chaos.com/t/rt-always-darker/50201/13 "2014-06-19T09:30:27Z")
here [https://dl.dropboxusercontent.com/u/33964271/VRay%20RT%203.max](https://dl.dropboxusercontent.com/u/33964271/VRay%20RT%203.max) ---
**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:** [June 20, 2014, 10:17am UTC](https://forums.chaos.com/t/rt-always-darker/50201/14 "2014-06-20T10:17:20Z")
Thank you very much for the scene. This is a known bug with Sub-Pixel-Mapping. Please turn it off and both engines will produce very similar result. ---
**Author:** ![dsolod](https://avatars.discourse-cdn.com/v4/letter/d/eada6e/32.png) [@dsolod](https://forums.chaos.com/u/dsolod)\ **Post date:** [June 23, 2014, 5:22am UTC](https://forums.chaos.com/t/rt-always-darker/50201/15 "2014-06-23T05:22:04Z")
Sorry, I wasn’t aware of that. Thank you Svetlozar! ---
**Author:** ![Karonte](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/karonte/32/23699_2.png) [@Karonte](https://forums.chaos.com/u/Karonte)\ **Post date:** [July 8, 2014, 3:59pm UTC](https://forums.chaos.com/t/rt-always-darker/50201/16 "2014-07-08T15:59:03Z")
> [@I dont trust machines - hehe Arnold](https://forums.chaos.com/t/i-dont-trust-machines-hehe-arnold/45193/2): > > Thank you very much for the scene. > > This is a known bug with Sub-Pixel-Mapping. Please turn it off and both engines will produce very similar result. yes but will it be corrected? I would like to use subpixel and use Vray-RT for previz test. In old vray all worked well. ---
**Author:** ![tashko.zashev](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/tashko.zashev/32/275280_2.png) [@tashko.zashev](https://forums.chaos.com/u/tashko.zashev)\ **Post date:** [July 9, 2014, 5:44am UTC](https://forums.chaos.com/t/rt-always-darker/50201/17 "2014-07-09T05:44:22Z")
> [@Karonte](#): > > yes but will it be corrected? I would like to use subpixel and use Vray-RT for previz test. In old vray all worked well. Yes, our developers are working to resolve this issue. When we have any update on this case, will post here.