Vray 1.5 dirtmap tutorial
The above image has been color corrected and blurred in photoshop to create the depth of field effect. This tutorial will be focusing on the dirtmap material which is included in vray version 1.5. I always like to use this material in my renders to add a little more realism. You need a basic knowledge of 3ds Max and vray to complete the tutorial.
Setting up the shader
Download the support files from here supportFilesDirtmap.zip<\/a>
Load the scene file and create a new Vray matarial
Assign the material to the building walls (i have grouped the walls of the front building so the windows are seperate)
Add the VrayDirt shader to the diffuse slot
The default options are displayed for the dirt material
Map a bitmap file texture to the radius slot and link the supplied dirt.jpeg file (set its U and V tiling to 2)
Map a bitmap file texture to the unoccluded slot and link the supplied diffuse.jpeg file (set its U and V tiling to 2)
Test rendering the scene
Render the scene to get a quick preview
You should get an image like the one above, notice there is very little dirt
Increase the radius to 2m and render again
Increasing the radius will make the building more dirty
Set the render setting as follows to produce a better quality image
Image width/height: 800 x 600
Image sampler: adaptive QMC
Antialiasing filer: Mitchell-Netravali
Adaptive amount: 1
Noise threshold: 0.005
Min samples: 8
Global subdivs: 2
The final image
You can plug in falloffs and shaders into the unnoccluded/occluded color slot to build more complex shaders.
For more information about the vraydirt material you can visit the online documentation.
I also used the following tutorial to help me setup the vray camera and sun.
About the author
I graduated in 2005 after completed a degree in computer animation and special effects and am currently working as a freelance 3d artist/visualiser. Some of my latest images can be viewed on my cg portfolio.