PMMA or similar light dispersion materials

[Namssorg]

Lately I have been rendering a lot of PC/ gaming products that have RGB lighting built into them.  Generally this is a milky white material (PMMA) that has some additives in it to really disperse light in all directions when illuminated.  Kind of like this example:


I have had some luck in using Keyshot's rough or cloudy plastic materials, and setting the inside surfaces of the illuminated part to be an area light material.  This works great in the early stages and I get something very realistic, especially with a gradient map on the area light. (If I have time I will create some non-NDA examples to show what I'm talking about.)

In later stages of development, when I am rendering models with a ton of engineering detail (actual LED strips, lenses within the light dispersion parts, etc.)  this gets a lot trickier to pull off. I can never seem to get the cloudy plastic material cloudy enough, or to bounce the light around internally enough to look believable.  I instead start to see through the parts more, and internal structures are more visible.  Cloudy material either looks way too rough/fake, or I doesn't hide enough internal structure while still letting RGB lighting illuminate the part.

What I would love to be able to do is have a slider that controls this somehow - so I can use the real part geometry to roughly simulate what the light dispersion might look like on the actual part, with the actual LEDs inside the product. (Hotspots and all.) 

Ideally my goal would be to replicate the material used in many of these applications - so that I can literally turn the LEDs on and off without having to change my materials.

[mattjgerard]

I've been trying to do this since KS 6. Good luck. Each time they release a new material, i get all excited, try it out, work it to death then go back to photoshop. The emitted lights just don't follow physics. Area lights might throw the correct color, but the color of the area light itself is wrong. So, have to either use a combo of emissive materials and area lights to try to get the correct look, or photoshop. There is no KS material that will look white when the LEDs are off AND diffusly transmit colored light at the same time. There is no one material that can look correct when the LED's are off and on. There is a "Light Pipe" material in KS cloud that comes close, and I think there are even PMMA presets in  KS cloud, but they just don't work the way they do in real life. My main frustration is that I can get a material to act properly when the LED's are on, but when the LED's are off, the material looks dark grey or and shade of grey, not the 95% white that it looks like in real life. even with all the color pickers in the material at 100% white, the material looks grey.

Its frustrating, and every once in a while I give it a shot, and its much better than it was a couple years ago, but still not workable for both lit and unlit materials.

[cameraman!1]

Lately I have been rendering a lot of PC/ gaming products that have RGB lighting built into them.  Generally this is a milky white material (PMMA) that has some additives in it to really disperse light in all directions when illuminated.  Kind of like this example:


I have had some luck in using Keyshot's rough or cloudy plastic materials, and setting the inside surfaces of the illuminated part to be an area light material.  This works great in the early stages and I get something very realistic, especially with a gradient map on the area light. (If I have time I will create some non-NDA examples to show what I'm talking about.)

In later stages of development, when I am rendering models with a ton of engineering detail (actual LED strips, lenses within the light dispersion parts, etc.)  this gets a lot trickier to pull off. I can never seem to get the cloudy plastic material cloudy enough, or to bounce the light around internally enough to look believable.  I instead start to see through the parts more, and internal structures are more visible.  Cloudy material either looks way too rough/fake, or I doesn't hide enough internal structure while still letting RGB lighting illuminate the part.

What I would love to be able to do is have a slider that controls this somehow - so I can use the real part geometry to roughly simulate what the light dispersion might look like on the actual part, with the actual LEDs inside the product. (Hotspots and all.) 

Ideally my goal would be to replicate the material used in many of these applications - so that I can literally turn the LEDs on and off without having to change my materials.

Replicating the material used in some of these applications would be huge! Once you do it, please post some pics.

[cameraman!1]

I've been trying to do this since KS 6. Good luck. Each time they release a new material, i get all excited, try it out, work it to death then go back to photoshop. The emitted lights just don't follow physics. Area lights might throw the correct color, but the color of the area light itself is wrong. So, have to either use a combo of emissive materials and area lights to try to get the correct look, or photoshop. There is no KS material that will look white when the LEDs are off AND diffusly transmit colored light at the same time. There is no one material that can look correct when the LED's are off and on. There is a "Light Pipe" material in KS cloud that comes close, and I think there are even PMMA presets in  KS cloud, but they just don't work the way they do in real life. My main frustration is that I can get a material to act properly when the LED's are on, but when the LED's are off, the material looks dark grey or and shade of grey, not the 95% white that it looks like in real life. even with all the color pickers in the material at 100% white, the material looks grey.

Its frustrating, and every once in a while I give it a shot, and its much better than it was a couple years ago, but still not workable for both lit and unlit materials.

It is really frustrating, that's a fact. I really hope this situation could change sooner than expected.

[Anindo Ghosh]

Probably an amateur question, but why the need for white cloudy plastic, instead of the built-in "Glass Heavy Frost Bright White" for the LED diffuser?