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 results. A much more efficient alternative is to fake the light scattering using an Emission volumetric shader.
Create an image of the light emission - black where ...
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 in the air area going to be blurred and boring too.
Just as a start, here's your scene with the Icosphere mesh light at 1/20th the size, and 100x the power:
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 pick Quick Smoke
After that a material has been created that looks like:
In order to also emit flames it can easily be extended to:
Note that the attribute ...
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 coffee. There are two volume shaders (three, if you count emission) - volume absorption, and volume scattering. Volume scattering is the slow and noisy one ...
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 this, add a mesh around your planet to act as a domain for the scattering. The domain's centre should correspond with the centre of the spherical 'planet'.
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.
Switch to Blender Render (the addon does not work under Cycles), add some cubes and turn them into clouds with the addon (the UI is located inside Tool Shelf T under ...
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 cylinder. This is achieved by calculating the distance from the origin in just two of the three dimensions (it's effectively a circle projected along the ...
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 through the volume, it is checked at a series of steps via a process known as "ray marching". Here's an example illustration, from this answer by the user sambler:
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 volumetrics).
Spot lamps must be placed far away in order to simulate a sun lamp, as spot lamps diverge, while sun lamps do not. Sun lamps do not have a fallof, while ...
Volumetric lighting can be done with volume scattering.
On cycles you have two basic choices:
1. Add volume scattering to the world volume. That will create a foggy/dusty atmosphere for the whole scene. It might take long to render, but the whole scene will be covered in a kind of misty/foggy atmosphere.
Note that anything connected to the background ...
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 be from object texture coordinates)
Directory : the folder where the image files can be found
Prefix : the image prefix (image are supposed to be in the format "...
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 will be extremely CPU intensive as it has to trace multiple rays from each point within the volume which is significantly extra CPU work.
Here's the shader in ...
The principles that apply for a forest scene are the same as for any other scene.
Think of volumetrics as shining a light in an environment that has suspended particles in the air, like haze or smoke.
All you need is to add a volume scatter node to the world's volume, and set it to a lower value than the default (in the following examples the value I chose ...
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 image texture is 2D.
See the wiki for a list of cycles textures with descriptions.
The density is controlled by the value (brightness) of the texture.
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 inside the volume. But you can make a cube bubble around the camera and parent it to the camera. E.g use a "Boolean Modifier" with the bubble (intersect) to cut ...
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
Points to keep in mind:
create the light super-bright and scatter density tiny - that way the small particles get enough light.
give the particles ...
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 image sequence be entirely contained in one image, strip-style (like below).
I found an open source tool called spritetool* that seems to work pretty well ...
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 control the lighting effect. I didn't have time here, but you might try several versions mixed over one another with varying lengths of ray so that they seem to ...
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 brightest and darkest parts of an image. See Render with a wider dynamic range in cycles to produce photorealistic looking images for a good introduction to a ...
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 light sources, such as at night.
In your case it looks like you are going for a more non-photorealistic look, so you may want to give up on trying to simulate ...
You have to use the volumetrics input in the material output node, instead of the surface input.
There are three different volume shaders. Volume absorption, volume scatter, and emission (yes, the same node used for making physical lamps).
Volume absorption is for simulating how light seems to vanish, like in smoke or clouds.
Volume scatter is for ...
For volumetric lighting
There are two basic options:
1- On your world settings you can add volume scatter and volume absorption.
Note that anything connected to the background surface shader will be ignored and will render black, so Enviromental textures will not work well with volume scattering (for more info read this post).
2-. Create some geometry ...
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 emission to be visible when saved as a PNG image.
If your volume has zero density, you could use the flame to drive the volume absorption density, adding just ...
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 long as you store it as EXR or any other format with associated (premultiplied) alpha channel, as it's the only way to store pixels that are both transparent ...
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 vector input of the gradient node defines the position and size of the resulting gradient.
Since in this case we want the center of the gradient to be in the ...
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 let light through:
If you want the liquid to use all 12 Transmission bounces you will have to set your 'Max' bounces to 12 as well.
Your cube is black because your volume scatter node is plugged into the surface input of the material output node.
From the manual page on the shader,
The Volume Shader output must be plugged into the Volume Input of
the Material Output
You can do it in Blender 2.71 or newer (which added support for volumetric data in Cycles).
Make a group in nodes that looks like on the screenshot below.
It's very important that you make the two "Attribute" nodes exactly like shown on the screenshot - "flame" lowercase and "density" lowercase - because it refers to data in the object.
The material itself:...
One of the standards for faking volumetrics is using billboard particles. Back in Blender v2.49, I used to use them all the time. I know that Weta digital used billboard particles for smoke in the LoTR movies. I started a thread on blenderartists.org about it. I did a series of video tutorials about it that are listed in the thread. They aren't the greatest ...