Setting Up A Render Pass For Glow

[casey33]

the topic is pretty self-explanatory. how would i set up a render pass to just render out the areas that glow.....so that i may overlay them at a later time?

thanks for the help/tips!

casey

[joojaa]

with glow applied, just the glow part, just the masks, masks and colors, or color masks?

[casey33]

say what?

here is an example.

i render out a scene. certain objects have glow applied to them. i also composite an occlusion pass to the scene. but once that is done, it kinda mutes out the glow.

what i want to do is render out the scene w/out glow...apply the ambient occlusion pass and then composite the glow areas on top of that.

hope that makes sense.

thanks!

casey

[joojaa]

QUOTE(casey33 @ 09/21/07, 02:45 PM) [snapback]273599[/snapback]
say what?

Yes but see do you want to MAKE the glow in post asweell while your at it this way you could adjust things like glow intensity after the fact. And if so how do you plan to make the glow happen, do you pull the values of

then just tick glow only for all your shaders

PS: your not supposed to multiply occlusion in sometimes it just works beacuse you have so simple order, but your supposed to multiply the occlusion by unshaded color of your surface and than do a weighted ADD to your scene. This incidentally wouldn't affect the glow in muting way (Tough youd porbably want to reglow anyway as you've changed the glows fundamental starting point but then youd want to redoo the glow form scratch).

So if you use tutorials like:

http://www.highend3d.com/shake/tutorials/g...hting--130.html

as your basis you should know its a bit off and uses certain artistic solutions for ordering fo the physically based idea on how it works. ITs easy to demonstrate why this ordering dont work right.

This is s classic trap youve fooled yourself in, its rather easy to be shown what to do. But very complex to understand why, and how did they get there (and if they did any mistakes on the road)

[casey33]

ouch, my brain hurts.

i appreciate you taking the time to explain the many facets of rendering. it will definitely help me improve my knowledge and understaning of it all.

a few days ago, i happened to come across a tutorial talking about render layers in maya. i just quickly glossed over it, but remember seeing an image that was showing just the glow information from the scene. everything else was black. so basically, the person was going to place the glow directly on top of the other render passes.

however, i cannot remember where i saw that tutorial.....d'oh!