How to get RE_Self_Illumination (filament) in a bulb?

[jasonhuang1115]

Hi,

I am wondering typically how to render a filament (inside a glass bulb) into a RE_Self_Illumination?

I have a scene where there is a typical light bulb with a filament inside. The filament is modeled and assigned with VrayLightMtl. The light bulb is modeled with thickness and assigned a regular transparent glass type of material.

The only way I can see the filament shown in the RE_Self_Illumination is when set the Bulb material's refraction to "affect all channels", but doing so my other Render Elements like the Extra Tex will get unwanted contribution from the bulb glass material.

Thanks.

[mr furious]

Render Elements are very good and helpful... especially when you want to break things apart.... but in many cases you'll get faster renders and the control passes you need just by setting up an extra render layer versus trying to stuff everything in one file.

I use render elements a lot, but sometimes... it doesn't make sense ... or isn't cost effect as a dedicated matte pass.

just my .02

Andy

[aweidenhammer]

Have to agree here. Sometimes you just have to render another pass. Can't get everything to work in one go.

[jasonhuang1115]

Thanks for the coments. I will break it into separate layers then.

cheers,
Jason

[irwit]

depending on what your scene looks like sometime you can assign an unused colour, eg, purple for me is rarely used, this way you can pick up a selection in nuke pretty easily. Just make sure its only purple for the eye and refraction rays and the correct colour for everything else.

[Morbid Angel]

glass in comp world is always a problem. In 3d, anything thats behind the glass is considered refraction, even if its self illuminated or specular. You can successfully fake glass by rendering a facing ratio pass and applying a warp or distortion based on that pass in comp to fake refraction, so then if your glass object is simply transparent you will get the rest of the elements out of it.

[pechart]

glass in comp world is always a problem. In 3d, anything thats behind the glass is considered refraction, even if its self illuminated or specular. You can successfully fake glass by rendering a facing ratio pass and applying a warp or distortion based on that pass in comp to fake refraction, so then if your glass object is simply transparent you will get the rest of the elements out of it.

Well that's a nice way to do it! Thanks for that.

[vlado]

There is also an option in the V-Ray material to propagate render elements through refraction - just set the "Affect channels" option to "All channels".

Best regards,
Vlado