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46 votes
Accepted

Volumetric Windows 10 logo effect

Emulate light scattering using a volumetric emission shader Using Volumetric scatter produces the most accurate results but required a considerable number of render samples to get satisfactory ...
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  • 42.2k
27 votes
Accepted

Volume Gods rays are not well defined

Because your light source is too big. God rays are just interesting/complicated shadow patterns hanging in space. If your light is throwing soft, boring shadows, the god rays of those shadows hanging ...
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  • 8,887
23 votes

Rendering smoke in Cycles?

As of version 2.73 from 2015: Make sure render engine is set to cycles (BI wouldn't create the required cycles materials) Select the object you want to emit smoke From the menu Object/Quick Effects ...
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  • 37.4k
23 votes
Accepted

How to: Exponential Fall Off for Volume Density?

You can use Vector maths and Maths nodes to calculate the 'altitude' above the planet and from there the atmospheric density and use this to control the density of the Volumetric Scatter. To achieve ...
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  • 42.2k
23 votes
Accepted

Create procedural spiral pattern

Final result One method is to create a volumetric cylinder and distort it by rotating it around the origin by an amount that varies based on the distance from the origin. First, create a volumetric ...
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  • 42.2k
22 votes
Accepted

Create a gradient effect, like for coffee?

This can actually be done quite easily (and efficiently) using the volume absorption shader: You're correct that this is a volumetric effect - it's dependent on how far the light travels through the ...
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  • 8,887
20 votes
Accepted

Distance from the surface as an input node for use with volumetric materials

You can use an OSL shader that measures the proximity of the mesh from within a volume. It works by projecting out rays from each point in the volume to probe the surrounding mesh. Be warned that this ...
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  • 42.2k
19 votes
Accepted

Question about volume samples

No, you are confusing volume samples, volume bounce depth, and ray-marching steps, which are all different controls. To start with, a short overview of how volume rendering works. As a ray passes ...
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  • 8,887
18 votes
Accepted

Is there an easy way to make volumetric clouds for Cycles?

Let's use the Cloud Generator addon to make nice clouds and the new Point Density Texture to render them inside Cycles! First enable the addon in User Preferences under Object: Cloud Generator. ...
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17 votes
Accepted

Using volumetrics in Cycles I have to have the light strength super high

There are several considerations here: Spot lamps and sun lamps are quite different (I suspect you are using a spot lamp to simulate a sun lamp, as sun lamps are not yet supported with world ...
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  • 152k
17 votes
Accepted

How to Create Dust Floating in the Air?

Mix an volumetric environment with a particle system: density of volume scattering will determine the amount of microscopic dust particles that create light rays particle system will add visible dust ...
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17 votes
Accepted

Render semi-transparent volume with cycles

PNG images can't represent objects that emit light but not block any light, due to the way they represent transparency. For that reason, you must always have some amount of volume absorption for the ...
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  • 7,401
16 votes

Using image sequence of medical scans as volume data in cycles

You can use an osl shader to do that. The code in the capture above creates an osl node. Here are its inputs and outputs : The input slots Vector : the mapping position (in this config, this must ...
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  • 46.2k
15 votes
Accepted

Using image sequence of medical scans as volume data in cycles

If you don't want to use OSL as in lemon's answer I have created a method to do this using only Cycles nodes. (Remember OSL isn't supported on GPU.) The downside to my method is that it requires the ...
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  • 24.3k
14 votes
Accepted

Controlling volume density

Yes, you can use any set of 3D values (e.g. procedural texture) you want (note that this means you can't use image textures. This is because you need the texture to be defined in 3D, and of course a ...
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  • 152k
14 votes
Accepted

Creating a Fluffy Cloud

Here's what your file looks like rendered with the Sun lamp strength set to 4 (it was set to 1): The key to having a good "fluff" is a wide dynamic range. Dynamic range is the distance between the ...
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  • 152k
13 votes
Accepted

Correct way to render crepuscular rays in cycles?

This is really a tricky one. First off, world surface shader and sun lamps dont work for world volume shading for now (as stated in the manual). Also, if you use object volumes the camera can not be ...
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  • 3,532
13 votes
Accepted

How to properly render smoke on a transparent background?

It's a viewer issue only. Try compositing over a gray background using the alpha-over node. If the result is correct, then your file output (without the gray background, of course) will be correct as ...
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  • 2,150
13 votes
Accepted

Why is this transparent material rendering black?

Even though you have 'Transmission' bounces set to 12 you are capping the 'Max' bounces to 4, meaning it's never doing 12 bounces. Here I have upped the 'Max' bounces to 6 and the liquid started to ...
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13 votes

Volumetric Windows 10 logo effect

You should look at the sunbeam node in the compositor - after render, you can add several filters and color mix nodes, but a really good way to get this effect seems to be with the sunbeam node to ...
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12 votes

Emission: Red glow while the object itself is white

If you really want to use Cycles: Add a box which encloses the entire scene, add a principled volume shader to the box and play with Density and Anisotropy: In comp you can add a Denoise node to save ...
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12 votes
Accepted

Emission: Red glow while the object itself is white

From a physically based rendering point of view, the problem you are running into is that Blender's HDR tone mapping is trying too hard to be helpful. The effect you see in the reference image occurs ...
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12 votes
Accepted

God Rays through window pane: Cycles

Use a cuboid to surround the scene, and use a volume scatter node as volume. Nothing shoud be connected to the surface socket. The default value of 1 for volume scatter is way too dense for practical ...
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  • 13.3k
11 votes
Accepted

Why there's not homogeneous volume scatter in 2.72?

Of course this feature has not been removed; it's just moved in the UI. You can now find it in the Settings subpanel of the World tab:
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11 votes
Accepted

How can a light cone (volumetric) be setup with cycles?

In real life these effects are caused by particles in the air such as water droplets, which reflect and scatter light. Usually these effects are only clearly visible when there is not a lot of other ...
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  • 152k
11 votes
Accepted

Why doesn't an Environment texture appear when the world has a Volume Scatter shader?

This is a known limitation, and it's not exactly a bug. Because the world background is an infinite distance away and a world volume shader is assumed to be infinitely large, there is a bit of a ...
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  • 152k
11 votes
Accepted

Create light rays in Cycles

Using a Gradient texture you can fade the volumetric emission off however you want: In this case, since it should fade out spherically from the center of the ring I used a spherical gradient: The ...
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  • 152k

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