# Glass blend and multi/sub-object material problem

**URL:** <https://forums.chaos.com/t/glass-blend-and-multi-sub-object-material-problem/128699>\
**Category:** Issues\
**Created:** [August 14, 2014, 1:25pm UTC](https://forums.chaos.com/t/glass-blend-and-multi-sub-object-material-problem/128699 "2014-08-14T13:25:23Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![vaslavo\_korytkowski](https://avatars.discourse-cdn.com/v4/letter/v/eb8c5e/32.png) [@vaslavo\_korytkowski](https://forums.chaos.com/u/vaslavo_korytkowski)\
**Post date:** [August 14, 2014, 1:25pm UTC](https://forums.chaos.com/t/glass-blend-and-multi-sub-object-material-problem/128699/1 "2014-08-14T13:25:23Z")

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Hello guys, ive created this image to explain better the errors we encountered on this matter, simple glass material works fine but on blend with standard corona material the shadows got wierd, on the 3rd sphere its a multi sub object with 2 ids material son instance, no problems but if you decide to copy the material (not instance just copy) on the seccond slot you get a refraction error, hope this helps.  
Version of corona A7.1 final

 ![CORONA BLEND AND ID BUG.jpg](https://europe1.discourse-cdn.com/chaosprd/original/3X/6/f/6fa670c08b68481e99e463a66db00d04b0704283.jpeg)

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**Author:** ![romullus](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/romullus/32/271095_2.png) [@romullus](https://forums.chaos.com/u/romullus)\
**Post date:** [August 14, 2014, 1:33pm UTC](https://forums.chaos.com/t/glass-blend-and-multi-sub-object-material-problem/128699/2 "2014-08-14T13:33:53Z")

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Duplicate: [refraction multi/sub object incorrect refractions - Corona for 3ds Max :: Issues - Chaos Forum](https://forum.corona-renderer.com/index.php/topic,3086.0.html)

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**Author:** ![vaslavo\_korytkowski](https://avatars.discourse-cdn.com/v4/letter/v/eb8c5e/32.png) [@vaslavo\_korytkowski](https://forums.chaos.com/u/vaslavo_korytkowski)\
**Post date:** [August 14, 2014, 1:37pm UTC](https://forums.chaos.com/t/glass-blend-and-multi-sub-object-material-problem/128699/3 "2014-08-14T13:37:28Z")

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thanks and sorry for missing that, heres is another example with polys detached no multi id only copy of the glass material and still got the error

 ![CORONA BLEND AND poly BUG.jpg](https://europe1.discourse-cdn.com/chaosprd/original/3X/8/e/8ed4f6c2062c459bcc8ee42e5afedec8e7eb4a58.jpeg)