Subsurface Scattering in All Directions

Started by WAS, October 19, 2019, 09:33:50 pm

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Matt

Here is an example that only uses decay, no volume/SSS.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

Thank you, I just actually just did this resetting the shader to default.

I am curious about thicker objects, it can get rather dark under sun, and from my experience gems seem to light up due to the internal refracting and bouncing focusing the light.

Do we turn up transparency? Or ramp the colour beyond 1?

I wanted to simulated gem clarity and brightness in a gem case.
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Matt

More examples showing different combinations of decay and volume colours:
Just because milk is white doesn't mean that clouds are made of milk.

Matt

Quote from: WAS on October 21, 2019, 10:38:24 pmThank you, I just actually just did this resetting the shader to default.

I am curious about thicker objects, it can get rather dark under sun, and from my experience gems seem to light up due to the internal refracting and bouncing focusing the light.

Do we turn up transparency? Or ramp the colour beyond 1?

I wanted to simulated gem clarity and brightness in a gem case.

Reflectivity and Transparency should both be 1. If the decay is too short for the object then you will lose some intensity, but it isn't realistic to boost the transparency above 1. For brightly coloured gems I would suggest keeping the decay distance higher than the size of the object and then you can make the decay colour as saturated as you want (although desaturated colours sometimes work better, I think).

An important part of what allows the light to bounce around inside the object is the "caustic intensity". I would leave this at 1. However, volumes with high density (lots of SSS) don't need this because the lighting is mostly due to SSS, and that is calculated separately.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

Quote from: Matt on October 21, 2019, 10:46:54 pm
Quote from: WAS on October 21, 2019, 10:38:24 pmThank you, I just actually just did this resetting the shader to default.

I am curious about thicker objects, it can get rather dark under sun, and from my experience gems seem to light up due to the internal refracting and bouncing focusing the light.

Do we turn up transparency? Or ramp the colour beyond 1?

I wanted to simulated gem clarity and brightness in a gem case.

Reflectivity and Transparency should both be 1. If the decay is too short for the object then you will lose some intensity, but it isn't realistic to boost the transparency above 1. For brightly coloured gems I would suggest keeping the decay distance higher than the size of the object and then you can make the decay colour as saturated as you want (although desaturated colours sometimes work better, I think).

An important part of what allows the light to bounce around inside the object is the "caustic intensity". I would leave this at 1.

Alright that makes sense. I'll just have to fiddle with the decay on each of the gems. Thanks for the input and sorry for the frustration. Thanks for that last bit. Was just messing with the caustic and it also does strange things above 1.
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Matt

Quote from: WAS on October 21, 2019, 10:49:53 pmAlright that makes sense. I'll just have to fiddle with the decay on each of the gems. Thanks for the input and sorry for the frustration. Thanks for that last bit. Was just messing with the caustic and it also does strange things above 1.

Thanks for saying that. I think we were both getting confused by the reflections, thinking they were transparency. So my original recommendation to reduce the decay distance probably didn't help at all.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

Quote from: Matt on October 21, 2019, 10:54:29 pm
Quote from: WAS on October 21, 2019, 10:49:53 pmAlright that makes sense. I'll just have to fiddle with the decay on each of the gems. Thanks for the input and sorry for the frustration. Thanks for that last bit. Was just messing with the caustic and it also does strange things above 1.

Thanks for saying that. I think we were both getting confused by the reflections, thinking they were transparency. So my original recommendation to reduce the decay distance probably didn't help at all.

Yeah, additionally I think trying to setup my SSS under simulated spotlight conditions of the box and light was premature. Sometimes the Sun in the default scene makes all the difference.
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