# Glow Mapping under Cycles?

**URL:** <https://blenderartists.org/t/glow-mapping-under-cycles/561743>\
**Category:** Materials and Textures\
**Created:** [January 8, 2013, 5:53am UTC](https://blenderartists.org/t/glow-mapping-under-cycles/561743 "2013-01-08T05:53:56Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![zauberexonar](https://blenderartists.org/user_avatar/blenderartists.org/zauberexonar/32/24464_2.png) [@zauberexonar](https://blenderartists.org/u/zauberexonar)\
**Post date:** [January 8, 2013, 5:53am UTC](https://blenderartists.org/t/glow-mapping-under-cycles/561743/1 "2013-01-08T05:53:56Z")

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Is it at all possible to specify a glow map with cycles, so that I can apply a glow/bloom shader effect post-process in the compositor?

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**Author:** ![Richard\_Marklew](https://blenderartists.org/user_avatar/blenderartists.org/richard_marklew/32/4458_2.png) [@Richard\_Marklew](https://blenderartists.org/u/Richard_Marklew)\
**Post date:** [January 8, 2013, 9:50am UTC](https://blenderartists.org/t/glow-mapping-under-cycles/561743/2 "2013-01-08T09:50:40Z")

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You can use a texture as the factor input of a mix shader, mixing your object material with an emission shader

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**Author:** ![zauberexonar](https://blenderartists.org/user_avatar/blenderartists.org/zauberexonar/32/24464_2.png) [@zauberexonar](https://blenderartists.org/u/zauberexonar)\
**Post date:** [January 8, 2013, 10:29am UTC](https://blenderartists.org/t/glow-mapping-under-cycles/561743/3 "2013-01-08T10:29:32Z")

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That’s not the type of glow I’m asking about. I’m looking more for an ‘aura’ effect

Example of the effect in InWorldz (a game similar to Second Life):

 ![](https://blenderartists.org/uploads/default/original/3X/d/7/d7a70e4ccfbb7d1cfdeb362e3a44ac1c53604301.png)

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**Author:** ![m9105826](https://blenderartists.org/user_avatar/blenderartists.org/m9105826/32/6760_2.png) [@m9105826](https://blenderartists.org/u/m9105826)\
**Post date:** [January 8, 2013, 10:25pm UTC](https://blenderartists.org/t/glow-mapping-under-cycles/561743/4 "2013-01-08T22:25:17Z")

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Glow maps are simply black and white maps that specify where to apply post-production filters in the game engine. The equivalent in an offline renderer like Cycles would be using a black and white map to blend between an emission shader and another shader(s) and then doing blur/glow in the compositor. That type of glow is not something you determine in modeling/material setup, it’s all done in post.

 ![](https://blenderartists.org/uploads/default/original/3X/b/2/b2a86a66a043c2050ffb415c3662d97330956a0a.png)  

[http://www.pasteall.org/blend/18731](http://www.pasteall.org/blend/18731)

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**Author:** ![zauberexonar](https://blenderartists.org/user_avatar/blenderartists.org/zauberexonar/32/24464_2.png) [@zauberexonar](https://blenderartists.org/u/zauberexonar)\
**Post date:** [January 9, 2013, 1:52am UTC](https://blenderartists.org/t/glow-mapping-under-cycles/561743/5 "2013-01-09T01:52:02Z")

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The problem though, is that I’m working with a node setup that uses blended emissive+diffuse to accomplish toon shading Though, now I think I have enough information to figure this out: just base the post-process glow on areas that have more than 50% emissive.

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**Author:** ![zauberexonar](https://blenderartists.org/user_avatar/blenderartists.org/zauberexonar/32/24464_2.png) [@zauberexonar](https://blenderartists.org/u/zauberexonar)\
**Post date:** [January 10, 2013, 6:43am UTC](https://blenderartists.org/t/glow-mapping-under-cycles/561743/6 "2013-01-10T06:43:21Z")

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Okay, unfortunately this didn’t work, as the compositor obtained the color data for emissive surfaces, rather than a percentage value. So, basing a glow/bloom shader off of emissive is a no-go.

Is there any way I can pass custom data to the compositor?

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**Author:** ![zauberexonar](https://blenderartists.org/user_avatar/blenderartists.org/zauberexonar/32/24464_2.png) [@zauberexonar](https://blenderartists.org/u/zauberexonar)\
**Post date:** [January 12, 2013, 3:22am UTC](https://blenderartists.org/t/glow-mapping-under-cycles/561743/7 "2013-01-12T03:22:51Z")

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Okay, I’ll ask again, is there a way to perform a blur/bloom glow effect in the cycles compositor _WITHOUT_ making any use of the emissive property?