Vacuum tube glow effect - quality reproduction, how to approach it?

tonpix

Hey guys, how would you approach recreating this light effect? Quality is priority and vaccum tube is going to be used in microworld, so it's relatively large (like a tree)


What I did so far, is this:

Basically I separate glass and internal part meshes, so I have option to disable 'cast shadows' in them - as far as I know, if you combine meshes (via import for example), you don't have separate mesh settings anymore (which is important because I need to disable 'cast shadow' for those parts so it doesn't block light). Then added emissive to filament, subsurface material to tube wrapping the filament, and another material, glass, then finally placed single spot light inside filament (which lights freely as you have sss + no shadow casting glass and wrapping tube.

I wonder how I can improve it, it's mostly about nice yellow-orange gradients

Other way could be hand painting emissive materials for both filament and wrapping tube, in painter, using baked thickness map to fake sss effect

but im not sure about quality, what do you think? It probably more time consuming as well considering I have 10+ vacuum tubes to do.

PS. I noticed without DFAO, light passes through glass with cast shadow, but with DFAO, glass blocks light until I disable cast shadow from glass. Is it bug, or expected feature/limitation?

Also, the eternal ue4 pain, no good glass I need to work on getting nice reflections..

Obscura

For best quality glass, just use forward shaded lit translucency. Expensive but looks good. It uses the reflection probes plus ssr so you should get the same quality reflections as on the opaque objects.

An alternative could be to use a cubemap but thats kind of limited. Like if you don't know how to get its mip maps, you are limited on constant roughness. This would be way cheaper though. Using an unlit material and a cubemap. But it would be lower quality as well, because of the single cubemap and no parallax correction.

To get bigger glow, use much higher emissive  value. You can also tweak the bloom settings in the post process volume.

I don't think distance field shadows supports translucency though. 

Ali_Youssef

What Obscura said, plus I'd suggest adding a dirt mask and plugging it into the opacity pin after a lerp node.
Your glass currently looks too uniform, but as for your reference, the dust and fingerprints are very apparent, and they help break up the "solid" look.

poopipe

some sort of facing ratio/fresnel based emissive to emulate the internal light bouncing is probably a good idea too. 

It's an interesting challenge this,  I'm half tempted to have a go myself (but I won't) 

JordanN

I don't got any tips too share, but if you want a video game reference, I remember The Order 1886 did the vacuum tube effect really well. And this was on basic PS4 hardware.