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I am trying to make a kitchen table/island which looks like the one in the reference image. I already put light inside the table, but I only want the yellow light to shine through the white parts of the marble texture. The black veines are supposed to block the light.

Is this somehow possible? If yes, can someone help?

Thanks in advance. If you need more screenshots let me know.

Greetings

Kara

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EAST_Kara
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1 Answers1

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One way you could do this is to dynamically create a mask from your marble texture that is used as a mix factor between high translucence and low/zero translucence areas of the material. So the veins would be low translucence, the whitish parts higher translucence.

translucent cube

This node setup shows the concept in action. At the bottom on the left is the marble texture I was working with; on the right is a preview of the mask, created using a color ramp.

node setup

They say you should always "add" translucence to your other shaders, but honestly I didn't like the way that turned out . . . too bright, hard to see the specularity. So I used a mix shader instead. Maybe less physically correct, but I think it looks better.

risingfall
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  • You are not supposed to add translucence, that is bs, not everything online is correct. You add volumetric absorption, maybe someone confused the two in Blender. – Jaroslav Jerryno Novotny Feb 13 '18 at 22:59
  • @Jerryno Thanks, I was just repeating something I heard from a couple of different sources, possibly the blender guru or cg geek was one of them. I'm definitely willing to believe they got it wrong. – risingfall Feb 13 '18 at 23:18
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    As usual, people on BSE have tried to answer this question in some detail. For example: https://blender.stackexchange.com/questions/15458/when-to-use-add-shader. The answer seems to be . . . people don't entirely agree, some think it should be used with translucence, because additional photons are indeed hitting the camera. Basically I just chose what looked good, and that seems to be the reigning consideration. – risingfall Feb 14 '18 at 14:10
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    That answer is from 2014 and not much was known then about building shaders inside of Blender community. When adding nodes, they don't "talk" to each other, so when light hits the surface it would reflect the full amount with diffuse shader and also pass through the same amount with translucent shader - the energy conservation is not kept. When mixing them, the translucent shader gets only what is let through the surface. You did it right and your common sense won over things on internet:) – Jaroslav Jerryno Novotny Feb 14 '18 at 14:21