# Various problems with RT

**URL:** <https://forums.chaos.com/t/various-problems-with-rt/47876>\
**Category:** Issues\
**Created:** [November 25, 2013, 10:44am UTC](https://forums.chaos.com/t/various-problems-with-rt/47876 "2013-11-25T10:44:38Z")\
**Posts on this page:** 1\
**Showing post:** 14

<div class="post-metadata">

**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:** [December 18, 2013, 8:47am UTC](https://forums.chaos.com/t/various-problems-with-rt/47876/14 "2013-12-18T08:47:52Z")

</div>

Hi James,

Please check my comments below on the RT/GPU issue you have reported.

> [@Thick Smoke Dissipation](https://forums.chaos.com/t/thick-smoke-dissipation/40559/57):
>
> I was going to start a new thread but makes sense to add to this list. A few issues from me:
> 
> 8: I am using a spiral gradient ramp for anisotropy rotation which doesn’t show up in V-Ray RT GPU.
> 
> 9: The V-Ray light material needs to be a much higher multiplier (even with compensate for camera exposure on) to be seen bright enough in RT GPU compared to rendering in RT CPU or the standard production renderer when using V-Ray physical camera. Here is a test scene:

-point 8) Anisotropy parameter of the V-ray materials is not yet supported by the GPU engine. We have this in our “To do” list.  
-point 9) We have some improvements on this in our V-ray 3.0 builds, but still V-ray RT/GPU needs to take into account every change to the “Compensate camera exposure” option of the V-ray Light material. I will update our system.

Thank you very much, your feedback is highly appreciated.

P.S. I will check the issue number 10 and will make an update here.

---

_[View the full topic](https://forums.chaos.com/t/various-problems-with-rt/47876)._