# r.SeparateTranslucencyScreenPercentage bug with worldPosition as UVs **URL:** \ **Category:** Rendering\ **Tags:** translucency, unreal-engine, question\ **Created:** [April 22, 2016, 8:23am UTC](https://forums.unrealengine.com/t/r-separatetranslucencyscreenpercentage-bug-with-worldposition-as-uvs/355046 "2016-04-22T08:23:19Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![dokipen](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/dokipen/32/1145419_2.png) [@dokipen](https://forums.unrealengine.com/u/dokipen)\ **Post date:** [April 22, 2016, 8:23am UTC](https://forums.unrealengine.com/t/r-separatetranslucencyscreenpercentage-bug-with-worldposition-as-uvs/355046/1 "2016-04-22T08:23:19Z")
I’m using worldposition to drive some uvs and when I lower the translucency screen percentage, the textures swim around when the camera turns. looks like the world position input isn’t being scaled with the resolution change. ---
**Author:** ![anonymous\_user\_6e7b421a](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_6e7b421a](https://forums.unrealengine.com/u/anonymous_user_6e7b421a)\ **Post date:** [April 22, 2016, 5:59pm UTC](https://forums.unrealengine.com/t/r-separatetranslucencyscreenpercentage-bug-with-worldposition-as-uvs/355046/2 "2016-04-22T17:59:48Z")
Hey dokipen, Could you provide me with some screenshots and simple steps to reproduce the issue on my end? I am familiar with the settings you are mentioning, and there are some known issues with WPO, but I would like to see if what you are seeing is related to the reported issues. Cheers, ---
**Author:** ![dokipen](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/dokipen/32/1145419_2.png) [@dokipen](https://forums.unrealengine.com/u/dokipen)\ **Post date:** [April 23, 2016, 3:45am UTC](https://forums.unrealengine.com/t/r-separatetranslucencyscreenpercentage-bug-with-worldposition-as-uvs/355046/3 "2016-04-23T03:45:43Z")
Sure. The easiest way to see it is with a cube and noise node. Make an unlit material with a noise plugged into it (lower the scale so you can see the noise pattern). I’ll try and get a scene together. ---
**Author:** ![anonymous\_user\_6e7b421a](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_6e7b421a](https://forums.unrealengine.com/u/anonymous_user_6e7b421a)\ **Post date:** [April 27, 2016, 3:36pm UTC](https://forums.unrealengine.com/t/r-separatetranslucencyscreenpercentage-bug-with-worldposition-as-uvs/355046/4 "2016-04-27T15:36:48Z")
That would be appreciated. Once I can get a reproduction case in front of me, I can move forward with the bug reporting process. ---
**Author:** ![dokipen](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/dokipen/32/1145419_2.png) [@dokipen](https://forums.unrealengine.com/u/dokipen)\ **Post date:** [May 2, 2016, 12:26am UTC](https://forums.unrealengine.com/t/r-separatetranslucencyscreenpercentage-bug-with-worldposition-as-uvs/355046/5 "2016-05-02T00:26:26Z")
Here you go andrew. Just open up project (4.11) and set r.SeparateTranslucencyScreenPercentage to 50 pc. Cheers Dan link text ---
**Author:** ![anonymous\_user\_6e7b421a](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_6e7b421a](https://forums.unrealengine.com/u/anonymous_user_6e7b421a)\ **Post date:** [May 3, 2016, 7:51pm UTC](https://forums.unrealengine.com/t/r-separatetranslucencyscreenpercentage-bug-with-worldposition-as-uvs/355046/6 "2016-05-03T19:51:19Z")
Thank you for taking the time to get a repro case over to me. I was able to verify what you are reporting and have gone ahead and entered a bug report for the issue (UE-30267). I will say I did find a temporary workaround to the swimming of the textures, by disabling the ‘Separate Translucency’ option within the material editor. Once the fix has been made it will be added into an upcoming full engine release or hotfix, and added to the list of known issues. If you have further questions or need additional assistance, please let me know. Thank you, ---
**Author:** ![dokipen](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/dokipen/32/1145419_2.png) [@dokipen](https://forums.unrealengine.com/u/dokipen)\ **Post date:** [May 3, 2016, 10:14pm UTC](https://forums.unrealengine.com/t/r-separatetranslucencyscreenpercentage-bug-with-worldposition-as-uvs/355046/7 "2016-05-03T22:14:58Z")
Cheers glad I could help. I think to get the option to control the resolution with that primvar then the material has to have that option turned on. I believe that is what enables it to be possible because that material goes into its own separate buffer which has its own resolution(which must be part of the problems). Anyway I’m sure someone will find a fix for it. ---
**Author:** ![dokipen](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/dokipen/32/1145419_2.png) [@dokipen](https://forums.unrealengine.com/u/dokipen)\ **Post date:** [May 19, 2016, 10:40pm UTC](https://forums.unrealengine.com/t/r-separatetranslucencyscreenpercentage-bug-with-worldposition-as-uvs/355046/9 "2016-05-19T22:40:03Z")
Thanks so much ! ---
**Author:** ![dokipen](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/dokipen/32/1145419_2.png) [@dokipen](https://forums.unrealengine.com/u/dokipen)\ **Post date:** [June 3, 2016, 4:56am UTC](https://forums.unrealengine.com/t/r-separatetranslucencyscreenpercentage-bug-with-worldposition-as-uvs/355046/10 "2016-06-03T04:56:51Z")
Uh oh, just seen this… Change 2994849 on 2016/05/31 by .Wright ``` Disabled fix for WorldPosition and ScreenPosition in downsampled separate translucency, since it breaks GetScreenAlignedUV (used in DepthFade), since the uniform buffer still contains full res buffer sizes ``` Any other fix ideas coming? I had a similar issue when using custom depth within a post process with worldposition and changing r.screenPercentage. Same problem I’m assuming. Cheers Dan