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Nicolas Jordan
06-04-2007, 09:14 AM
I am working on an animation of water swishing around inside a light bulb. The will show up on anything outside the transparent bulb surface but not inside the bulb. I am trying to give the filament a glow. The bulb surface is made up of 2 layers of transparent geometry for air polygons. Does anyone know how to get the glow to show up on the filament? Any help and suggestions are much appreciated.

gerry_g
06-04-2007, 09:41 AM
I think Glow like Sas Hair has problems with being behind transparent surfaces because there both post process pixel filters, i.e. not part of the render, maybe I'm wrong and someone else knows better, but tricks like this have to be comped after the fact.

Nicolas Jordan
06-04-2007, 09:57 AM
Thanks for the reply gerry_g. Ya, your probably right since it's rendered after everything else it likely won't show up. That makes sense. I guess I will have to render it out separately and composite it in.

j__
06-04-2007, 01:02 PM
Thanks for the reply gerry_g. Ya, your probably right since it's rendered after everything else it likely won't show up. That makes sense. I guess I will have to render it out separately and composite it in.

I noticed this problem too recently.

You could render a seperate pass, or do what I did and use corona which is a great thing to be using as often as you need it anyway, which gives you a lot more control than glow as well. You can use Special buffers (which have been around in LW for ages) as well with Corona to effectively tell it to only affect a specific surface. SB basically just allow some arbitrary extra values for surfaces and you can tell a corona instance to use that as the input.

Works very well. Corona can be textured too.

Nicolas Jordan
06-04-2007, 10:07 PM
Thanks for the reply gerry_g. Ya, your probably right since it's rendered after everything else it likely won't show up. That makes sense. I guess I will have to render it out separately and composite it in.

I noticed this problem too recently.

You could render a seperate pass, or do what I did and use corona which is a great thing to be using as often as you need it anyway, which gives you a lot more control than glow as well. You can use Special buffers (which have been around in LW for ages) as well with Corona to effectively tell it to only affect a specific surface. SB basically just allow some arbitrary extra values for surfaces and you can tell a corona instance to use that as the input.

Works very well. Corona can be textured too.

Thanks for the tip. I will give that a try! :)

Nicolas Jordan
06-06-2007, 01:53 PM
Corona is effecting the specular highlights in my scene. Does anyone know how I can get Corona to apply to only one surface or object layer?

byte_fx
06-06-2007, 04:49 PM
AFAIK corina is post process that affects the entire image.

You do some control - quite a bit actually - via it's set up options.

Maybe you can find a happy medium that way.

Or try fiddling with each surface's settings so you get the most effect on those that need it.

byte_fx
06-06-2007, 04:51 PM
Alsp - try turning off all the shadow options for the glass and air layers.

j__
06-07-2007, 02:05 AM
ok so just to clarify for people:

the goal is:

something glowing through a transparent object and glow won't do it:

in advanced-->special buffers of the surface that you want to glow (and therefore glow through a different transparent object/surface in front of it) just set the top value in SB to say 50% that will do.

Then add a corona pass in scene>image process

then set corona's input to special buffers,

then set that input level to something less than that 50% say 33%

click the texture thing if you want to give the glow a color, you can just use a procedural>value for a flat one color.

just leave corona's other values the same to begin with, well actually crank the strength up to 90% so you can see it easily and indeed you may well want it high for this kind of glow.

render

that's it

need more glows or different corona effects on the entire render or different objects ? i.e for specular....add more corona instances as necessary.

Also be aware, I'm not sure special buffers save with the object..they probably do...but you can't set special buffers in modeler, they only mean something in Layout.

I've attached a pic of a cigarette tip glowing through a transparent pink think in the foreground.

Nicolas Jordan
06-07-2007, 03:06 PM
ok so just to clarify for people:

the goal is:

something glowing through a transparent object and glow won't do it:

in advanced-->special buffers of the surface that you want to glow (and therefore glow through a different transparent object/surface in front of it) just set the top value in SB to say 50% that will do.

Then add a corona pass in scene>image process

then set corona's input to special buffers,

then set that input level to something less than that 50% say 33%

click the texture thing if you want to give the glow a color, you can just use a procedural>value for a flat one color.

just leave corona's other values the same to begin with, well actually crank the strength up to 90% so you can see it easily and indeed you may well want it high for this kind of glow.

render

that's it

need more glows or different corona effects on the entire render or different objects ? i.e for specular....add more corona instances as necessary.

Also be aware, I'm not sure special buffers save with the object..they probably do...but you can't set special buffers in modeler, they only mean something in Layout.

I've attached a pic of a cigarette tip glowing through a transparent pink think in the foreground.

Thanks for explaining that. I had seen the Special Buffer in there but was not sure what it was for. This helps lots! :D