Surface Imperfections: Dirt mask & Occlusion mask — Houdini Mantra Tutorial

In this episode I go over creating surface imperfections and overall building a final material using rendertime Dirt and Occlusion masks. Interestingly enough, we will control the look of the hard surface shader by dividing a triplanar mask by negative values. The results might surprise you!

Occlusion and Dirt Masks in Mantra

On top of the bevel shader that we used in the previous Mantra tutorial, we can also utilize at least two more procedural mask generators to make our surfaces more detailed. And we will not use UVs again, instead do everything rendertime, meaning it will compute the result during the rendering phase.

The Occlusion and Dirt masks are both working on generating masks, usable for creating layered materials. They do almost the opposite effect of each other, but if we control the radius and use it with a little bit of planning, we can create great looking imperfections in no time. Well, at least within the time it needs to render the picture.

Surface Imperfections

Things that appear like accumulated dust, or grunge from water, or just dried up water leaks, all work to create a more believable material in your renderings. Things are pristine looking only when you open the box, and unless you are really working on showcasing a super slick and clean version of your geometry, you might want to make the viewer believe that the item was used for some time before it appeared on the screen, making it more believable. So, that is exactly what we will be working on. Let’s learn!

Houdini Mantra Series

The post that you just finished reading (and watching) is just a part of a free workshop on Rendering and Shading with Mantra. You can select related tutorials on the subject, or you can go to the page with all the available course parts on the subject.