Maya Lighting tutorial (Specific effect)

count23

I'm looking for a tut somewhere that'll explain how to use translucency/transparency with maya lights to give the effect of a backlight light panel, like a sconce or fluro light. Anyone seen or made a good one out there?

I'm prefering to avoid self luminance because it just wont give me the same effect (I'm specifically looking for the style that makes it obvious that there's a light behind a plastic/glass sheath - the falloff from the centre I couldn't effectively pull off with self illumination).

I'm trying to create photorealistic sconces and I'd prefer not to just use textures for it since I want the sconces to be real light sources too.

IRML

in my experience it's all in the surface, depending on the look you want it could be a translucency shader or blurry refraction if you want more transparency

afraid I don't know what a sconce is otherwise I'd be more helpful

Melak

I have never really messed around with translucency, but a mr fast SSS mat could work:

count23

It kinda works, I can see the falloff from the light source, probably just needs a mask to make it more noticable down the line, I was hoping to replicate an effect more like this: http://www.google.com.au/imgres?um=1&hl=en&sa=N&biw=1920&bih=1136&tbm=isch&tbnid=r3jErmgwDpYMcM:&imgrefurl=http://www.brandlighting.com/leucos_todd.htm&docid=X2E7NqyxYAKp5M&imgurl=http://www.brandlighting.com/images/leucos/todd-sconce-a.jpg&w=300&h=350&ei=3bNnT_W8D8Tz0gHZq-WaCQ&zoom=1&iact=rc&dur=345&sig=107811032487964714629&page=1&tbnh=123&tbnw=104&start=0&ndsp=93&ved=1t:429,r:0,s:0&tx=72&ty=71

IRML: I was going down the texture route originally then some maya genius wandered past and told me to just use translucency and a light. didn't bother to explain how tho, hah.

IRML

yeah that effect is translucency, it could be done with a texture with no loss of quality, blurry refractions will change with the viewing angle but translucency doesn't really

the most basic shader for this in LW just projects the light from one side of a face onto the back side of it, so if you can find something similar in maya that would work, otherwise SSS

if you're having difficulty with that then you could set up the light, and a plain white diffuse surface for the sconce, then bake the light cast on the inside and use it as a luminosity map to fake the translucency on the outside

Melak

If you use inverse square decay for the light (which I din't for some reason) you get more visible falloff.

Either way though, translucency or SSS, I think the light fixtures geometry will swallow all the light, and your fixture won't light up the surroundings

count23

thanks guys.

@IRML i'll look into the baking suggestion, It honestly never occured to me.

I guess I just have to remember to add an extra few ray traces for the light out from behind the cover if I'm going down the translucency route.

Melak: Which is a better light type for this sort of work? I was doing this with area lighting, would a point or omni light yield a better result or are they really no different when applied this way?

Melak

Nadesico wrote: »

Melak: Which is a better light type for this sort of work? I was doing this with area lighting, would a point or omni light yield a better result or are they really no different when applied this way?

well, I was using an mr area omni with a sphere shape and radius so it's about the size of a lightbulb.
I messed around with translucency, but I just can't get it to look right - it only works if you use it with transparency of course, but if the object isn't lit well from the outside, it basically becomes transparent and only the lit insides are visible - which is not how I recall sconces working.

It could just be that I have no clue how to properly use translucency

On the other hand, translucency only works on flat geometry, while SSS in mr requires that your geometry actually has a closed volume.

The actual effect looks like plain translucency, as irml said it doesn't really change with perspective, but I have no clue how to make that work properly. Simply baking the lighting from the inside and putting it on the outside seems like the easiest solution.