Soulburn Studios Art Lessons

Dust Material
By Neil Blevins
Created On: March 13th 2008
Updated On: Dec 4th 2024
Software: Blender or 3dsmax (vray) or 3dsmax (scanline)

Go here to read this tutorial in Russian.

Dust is fine particles that build up on another surface overtime. Dust can be regular dust you get in your house on that top shelf you rarely touch, or some sort of industrial dust in a factory, or dust that comes from an environmental source like fine ash from a volcano. Here's a tutorial on how to create a basic dust material.

Reference

Here's the material we are trying to emulate in CG. This photograph is of a dumpster with dust on the upper facing parts of the side wall.

Software Agnostic Material

The basic ingredients are as follows:

Shading: A Dust material generally doesn't exist on it's own. You want to cover another surface with dust. So this is the sort of material you'd want to layer on top of another material.
Color: light grey or colored based on the sort of material that's causing the dust (if the dust is on your car, and you work at a lumber yard, the dust may be slightly yellow/brown)
Bump: Very small speckly noise, to represent the tiny particles that make up the dust
Opacity: Shows up only on the top facing surfaces of your object. Also, some larger variation to the opacity of the dust to represent layers of dust building up in a random fashion

Ways to make it more realistic:

Replace the dust bump procedural noise with a triplanar with a more complex bitmap to simulate larger and smaller clumps of dust.
Replace the procedural noise in the Opacity Mask with a triplanar with a more complex bitmap that has stuff like fingerprints or brushed areas, like someone was trying to clear away some of the dust but missed some spots. Or even water drips like in the reference above.

Blender Example

Here's the shader for Blender...

The base material is a Mix Shader. It mixes between a base shader (in this case, a simple blue-green material) and our Dust Material. The Factor is a map that defines where dust is placed.

The color of the dust material is just a slightly grey/yellow color.

For the bump, a noise texture with a very small size, and medium strength. The Noise Texture is hooked up to the Object space of the 3d object, which applies the noise to 3d space instead of using something like UVs.

The mask map map is a little more complex. First, I want to choose only the up facing parts of the object, with a slight gradient so the transition isn't too harsh. For this I choose a Vector Math node set to Dot Product. I use a Geometry node to get the normal of a particular face of the object, take the dot product of that and the vector <0,0,1> which is a vector pointing up, and the result is creating a mask that is white on up facing faces, and black everywhere else. I run that through a Color Ramp node to adjust how contrasty this texture is. I then create a Noise. This is a pretty large noise, and represents the random uneven buildup of dust over time. I then multiple this noise with our up facing mask to get our final mask.

To add dust to any material, just replace the Base Material with whatever material you want to apply the dust to.

Here's the resulting render.

Here's the blend file, Blender 4.2: dust_material_blender.zip

3dsmax (vray) Example

Here's the shader for 3dsmax for the vray renderer.

The material is a VRayBlend material. Material 1 is the light blue/grey material. Material 2 is the Dust Material. The mask for Material 2 is a map that defines where dust is placed.

The color of the dust material is just a slightly grey/yellow color.

For the bump, a noise with a very small size, and medium intensity.

The mask map map is a little more complex. First, I want to choose only the up facing parts of the object, with a slight gradient so the transition isn't too harsh. For this I choose a Falloff map set to "Towards/Away" and "World z-Axis" (since in max the z-axis points up). Note, you must use "Towards/Away" and not "Perpendicular/Parallel", or else dust will appear at both the top and bottom of your teapot. I then modify the curve control of the falloff to produce a nice transition, modify this to your own pleasure.

In the Towards map, I place a Noise. This is a pretty large noise, and represents the random uneven buildup of dust over time.

To add dust to any material, just replace the Base Material in your VrayBlendMtl whatever material you want to apply the dust to.

Here's the resulting render.

Here's the max file, 3dsmax 2022: dust_material_3dsmax_vray.zip

3dsmax (scanline) Example

Here's the shader for 3dsmax for the scanline renderer.

The material is a blend material. Material 1 is the light blue/grey material. Material 2 is the Dust Material. The mask is an opacity map to define where dust is placed.

The color of the dust material is just a slightly grey/yellow color.

For the bump, a noise with a very small size, and medium intensity.

The opacity map is a little more complex. First, I want to choose only the up facing parts of the object, with a slight gradient so the transition isn't too harsh. For this I choose a Falloff map set to "Towards/Away" and "World z-Axis" (since in max the z-axis points up). Note, you must use "Towards/Away" and not "Perpendicular/Parallel", or else dust will appear at both the top and bottom of your teapot. I then modify the curve control of the falloff to produce a nice transition, modify this to your own pleasure.

In the Towards map, I place a Noise. This is a pretty large noise, and represents the random uneven buildup of dust over time.

To add dust to any material, just replace the Material in slot 1 with whatever material you want to apply the dust to.

Here's the resulting render.

Here's the max file, 3dsmax 2022: dust_material_3dsmax_scanline.zip