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Beveling a Polygon Edge

For use with Shade 8

Shade gives you a convenient Bevel tool- but it works only with edges of spline-based objects. To bevel an edge on a polygonal object, we'll need to use Shade 8's polygon tools to edit the shape by hand....Shade's spline-based modeling tools give users many ways to create complex, realistic curved surfaces. Once those surfaces are converted to polygons, however, the tools and techniques used to manipulate them are different. This tutorial will demonstrate how to use Shade's polygon and vertex editing tools to bevel a sharp edge on a polygonal model.

For starters, let's create a polygonal shape. Revolving an open line in Shade gives us a sort of flattened top-hat shape as shown-

Converting this to a polygon mesh is as easy as selecting the revolved line in the Browser and choosing Convert>Convert to Polygon Mesh, and setting the desired fineness of the resulting mesh. Regardless of mesh density, the resulting shape has a sharp, "stair-step" edge as shown-

To smooth this out, we'll probably need to subdivide the mesh, unless we chose a Fine or Very Fine setting for the polygon conversion. Note that Shade's subdivision operation only works if the polygon(s) being subdivided are quadrilaterals- triangles or multigons won't subdivide. To select polys to subdivide, enter Modify mode, ensure that you've chosen to select by face (see below), then click and drag across the surfaces you want to select. To select more polys, shift-click on them individually or shift-click-and-drag across them. If you get a few that you don't want, you can Command-click (on Mac) or X-click (on Windows) to deselect them.

With the proper polygons selected, click Divide and choose how far you want to subdivide the edges of each selected polygon. Choosing 2 divides each edge in 2- so each polygon becomes 4 new smaller polys; choosing 3 divides each selected polygon into 9, etc. For purposes of this tutorial, we'll choose 2.

Now that the polygons have been properly subdivided, we can create the actual bevel. To do this we'll need to select the vertices that form the corner(s) of our shape, and move them around. Selecting the right vertices can be a bit tricky- first, we need to choose to select by vertex (see below.) Then it's a matter of clicking and dragging to select a group of vertices, in just the same way that we did to select the faces before we subdivided them. Likewise, if we select some vertices we don't want, we can Command-click or X-click and drag to deselect them.

With our vertices selected, we can Shift-Command-click or Shift-X-click and drag to move the selected group of vertices- or choose Move>Scale or Move>Uni-Scale to manipulate all the points at once. To create a bevel, we can shrink the selected group of vertices a bit and then drag them downwards as shown.

One thing to remember- most rendering engines can smooth off the polygons to a greater or lesser degree, so even if the edges look a little rough in the preview, the final render can potentially turn the bevel into a smooth curve.