Is there a tip-to-tail tutorial on volumetrics?

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aprilwine
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Joined: Tue Apr 20, 2021 7:31 pm

Is there a tip-to-tail tutorial on volumetrics?

Post by aprilwine »

I'm using the latest Blender plugin, and I can't get them to work. I made a scene with a text-shaped window (no glass in it at present). I created a cube to act as the volume, and grabbed bits and pieces of information from other tutorials that were made on other versions. But it doesn't work. Is there a simple document with steps 1, 2 and 3 to make a "hello world" volumetric scene?
novolume.png
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DionXein
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Re: Is there a tip-to-tail tutorial on volumetrics?

Post by DionXein »

Just use same volume material for camera and fog object. And use lower values for scattering (0.005 - 0.1)
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TAO
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Re: Is there a tip-to-tail tutorial on volumetrics?

Post by TAO »

nice how the letter works as light with no soft light part?
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DionXein
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Re: Is there a tip-to-tail tutorial on volumetrics?

Post by DionXein »

TAO wrote: Wed Apr 21, 2021 9:46 am nice how the letter works as light with no soft light part?
Just distant sun + letters are glass with shadow colour equal to glass color
aprilwine
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Joined: Tue Apr 20, 2021 7:31 pm

Re: Is there a tip-to-tail tutorial on volumetrics?

Post by aprilwine »

Thanks DionXein. Why on earth does the camera need to have a "material"? 🤔 That seems counterintuitive... but I'm glad you helped me figure it out.
aprilwine
Posts: 3
Joined: Tue Apr 20, 2021 7:31 pm

Re: Is there a tip-to-tail tutorial on volumetrics?

Post by aprilwine »

To sum up, here are the steps as I understand them, for Blender 2.92:

Create a scene with a camera and lights in it. (Set LuxCore as the render engine.)
01.png

Turn on Light Tracing in the Render Properties to get caustics to work, or use the Bidir engine (if you want caustics).
02.png

Create a cube just large enough to enclose all the objects in your scene and call it Fog.
03.png

Create a new material for the fog and assign it Null (Transparent).
04.png

Select the camera. In the Object Data Properties panel (camera icon), turn off Auto Detect Camera Volume. Click "New" to create a new volume; then click Show to load the nodes in the LuxCore Volume Nodes panel.
05.png

Delete the Clear Volume that was created. Instead add a new Homogeneous Volume. Reduce the Scattering value to somewhere between 0.005 and 0.3.
06.png

Select the Fog cube again and go back to LuxCore Material Nodes. Click "Add" next to "Interior Volume." Select the Camera_Volume to create a pointer to.
07.png

EXTREMELY IMPORTANT: You may have to quit and restart Blender to get this to actually render any fog.
Volume Render.png
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