The Basic's of Render Booleans

Ryan Ernst takes us through all the basics of using render booleans in Modo. Render booleans are volumes that subtract from geometry during the render process. Render booleans don't actually affect geometry.

In this video I go over the basics of using Render Booleans.  I go over setting up a basic render boolean cut, then we go through and exclude items from that boolean.  I also show how to set the color of the cut lines.  Last but not least I'll animate the boolean growing to cut through the mesh for a cool effect.  If you would rather learn by reading, you can learn everything you need to know below.  

Adding Render Booleans

To add a Render Boolean to your scene, click Add Item > Volumes > Render Boolean   
The Render Boolean will default to a sphere, you can choose from basic shapes in the Particle Geometry or your can use a custom mesh as your cutout.

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Custom Mesh Cutout

A. Create a mesh you want to use to cut your rendered mesh.

B. Add that mesh to your render boolean properties in the Surface Volume Parameter.

C. Preview you scene to see the effect.

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Excluding Items

To exclude items from render booleans, add a custom material to the part you want to exclude.  In the material properties go to the material rays tab and un-check Enable Surface Clipping.

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Colored Cut Line

The colored cut line defaults to your base material, if you want to easily change the color add a contant over your base material or change the diffuse in the material itself.

Multiple Custom Colored Booleans

If you want to use multiple render booleans with different color cutouts your will need to Create an Item Mask by right clicking the boolean and selecting Shade > Create Item Mask, this will generate a custom material in the shader tree to control the color of the cut line.