cycles - rendering

rendering fog... or mist

They are not the same horror movie.
The fog, the darker one, took 127 minutes to render 100 frames. The mist, the lighter one, took 21 minutes to render 100 frames.


The set up is completely different in that mist is a render pass that gets applied in Compositing.

Setup for Mist

1. In the render layers pannel turn on the Mist pass.
2. In the world pannel you’ll find the controls for the Mist Pass. This is where you adjust how much mist is in the scene. Start indicates the distance from the camera the mist will start. Depth indicates the distance from Start that the scene will be visible. Beyond depth there is only Mist…
3. In compositing this is the image that is rendered.
4. And this is the Mist pass that was rendered.
5. Mix them together and this is the outcome. What is nice with mist is once in the compositor you can change up the intesity of the mist, invert it, color it and animate these settings to produce this… (and it won’t take long to render so you can throw in a monkey.)

mist video


Fog, on the other hand is rendered along with the image. It is a volume attribute of the World’s cycles material. And being so, it is effected and affects the lights and objects in the final render… which acounts for the higher render time.

Setup for Fog

1. In the world pannel, for Volume: select Volume Scatter.
2. The volume scatter controls will appear and all things can be adjusted and animated.
3. A Volume Scatter node will be added to the World cycles material.
Note how the light is affected by the Volume Scattering of the fog… just like fog… not unlike a typical December day in Skopje. Except in Skopje it is not fog… it’s air pollution…

fog video

Mist, on the other hand, does not have this level of realism.


It’s in the air…


Greater than

The math > used to define textures As well, the cube has a few Solidify modifiers creating the layering. source:





displacement creating complex surfaces source:


1. create greeble


2. apply greeble to object as a displacement.


1. there are 4 objects; suzanne, cube, circle2, circle1.
2. circle 1 has a transparent noise texture that is animated.

3. circle 2 has a simple transparent

4. and the cube has an orange mat with a transparent mix with the fac effected by the transparent Depth in the scene. The Transparent depth in sent through a Math node Subtracting 2.000.


shadeless material



There are two node trees. The top one the Diffuse BSDF is disabled so there is no fall off of the green color onto the ground plan. On the bottom one there the Diffuse BSDF is mixed with the Emission.  The Emission light is canceled out by the Light path/Is Camera RAy. But the green from the Diffuse is still falling off to the ground plan.

blurred textures

Geometry Position controling color

mix colors


Keys highlighted in the nodes…



simulated FLAME node