
	Reduce and Multiply: Decimated Meshes

When you are using the Networks tool, there are two major stages in the "polygons to NURBS" process: first define patches, and then extract displacement and color maps. The first stage is highly interactive, requiring lots of user input. The second stage is highly CPU intensive, requiring almost no user input.

For these two different stages its very useful to have two different polygonal meshes available. For the first stage, use a low polygon count (i.e. decimated) mesh, and when you draw curves and fit patches, CySlice will respond much quicker. These pre-fitted patches can then be used in the second stage with the original maximum polygon count (i.e. not decimated) mesh.

To reduce the number of polygons in the mesh, first open up the Reduce/Multiply panel (see Figure 21. Then use the <g> key to box or paint select the area of polymesh that you want to reduce; the number of faces selected will be shown in the Num field. Note: The quickest way to select all faces is to type the <g> <s> key sequence.

Figure 21. Polymesh Reduce and Multiply

You can then enter the reduced number of faces you want into the Num field, or type a percentage value less than 100 into the following % field. Be sure to hit <Enter> after typing either value, and the other field will update.

Finally, click on the Do It button and the selected faces will be reduced to the target number. This may take a few minutes, especially for larger meshes.

The Feature Weight is set at 50% by default. If you set this value to 100%, then areas of high curvature in the polymesh will be reduced much less than other parts of the mesh. Set this value to 0%, and the mesh will be more evenly reduced.

There is no undo from the polygon reduction, so make sure your mesh is saved before experimenting with different reduction settings.

If your polymeshes are large, and you are running low on available RAM, save the decimate meshes out and reload them before continuing with patch fitting or slicing. Additional RAM is used during the reduction process, and the best way to release that back to the system is to quit and reload the reduced mesh.

Multiplied Meshes

To increase the number of faces/vertexes, use the <g> key to paint the area you want to multiply, then type a percentage value greater than 100 into the % field, or enter an increased number of faces into the Num field. Finally, hit the Do It button to multiply the selected faces. Again, this may take a few minutes if you have selected a large area of mesh.

To abort the multiply, first make sure that the mouse pointer is in the graphics window, then hit the <Space> bar.