Smoke in glass?

Hey everyone :slight_smile:

I’m having a bit of a problem here… I wanted to create a torch model with a smoke simulation for the fire…
Now… it all works fine, except that when I render it as RGBA png (because I need the background to be transparent), the flame becomes almost invisible where it is not in front of anything… where it’s in front of the torch model, it shines bright like it’s supposed to…
So to make up for that, I wanted to change my model a bit, so the flame would be inside a glass tube, that would sit on top of the torch (making the model a bit more modern-stylish-whatever :stuck_out_tongue: )…
But the flame doesn’t render inside the glass… the torch model does, and if I make the glass shorter, so the top part of the flame is not inside the glass, I can see the flame…
Hope that description makes sense…

I’d be very thankful for any suggestions either on how to make it shine bright on a transparent background or how to make it render inside a glass object…

Thanks in advance,
-Daniel

*** Thread moved from Blender Discussion to Support forum ***
Please use the appropriate support forum for support questions

Oh sorry about that, thanks for moving it :slight_smile:

Does this forum support bumping? This thread came up on Google search and I’m having that same problem now too. I’ve got a poly object with fresnel applied, and I want to use particles with halo applied (I know there is smoke domain available, but for the effect I want I’m using particles with halo applied.)

If I have the particles inside or behind the glass they don’t render at all, but if you move it halfway above or to the side of the glass poly the side outside will render. Seems odd you can’t render smoke inside glass.

Are you speaking about Cycles or BI render engine?
Please, specify.

paolo

It’s been a long time since this thread was created, but I have the same issue, can’t see smoke through the glass material, it’s not inside the glass though, just behind it (inside the cup), it’s in Cycles Blender 2.92.0
The smoke material is emission shader in the volume output, volume’s baked with mantaflow

I can’t reproduce the issue. Could you share the problem .blend file?

sure, for_support.blend (3.1 MB)

If I mute the first multiply in the volume material (removing the contribution of the light path node) the volume displays correctly. This makes sense: using is camera ray, only the volume that is seen directly by the camera will display; that part seen through the glass is not seen directly by the camera (or rather, the camera sees it in the glass material, not the volume material).

If I put a math → maximum node between the light path and multiply nodes and plug in both is camera ray and is transmission ray, I get the expected result.

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Thanks, that makes sense. I was pretty sure I had checked this part, but I suppose I hadn’t checked good enough somehow.