Cosine Spacing Plugin For Rhino
As I outlined in my post on my method for drawing airfoils in Rhino, the curves should be divided using a cosine spacing, rather than the typical division methods provided in Rhino. I had a friend of mine whip up this plugin for me, and so it’s a little rough around the edges, but it gets the job done. Here’s a user guide:
After you download it, unzip it, and then place it in your Plug-ins folder, which is inside your Rhinoceros 4.0 folder. Then go to File->Properties->Rhino Options->Plug-ins to install the plugin.
Simply type CosSpacing on the Rhino command line to bring up the tool.
The first prompt will ask you how many segments you’d like to divide the curve into. Enter the number and press enter.
The second screen can admittedly be a little confusing, but it’s where you toggle between full cosine spacing, and half cosine spacing. The default setting is full cosine spacing, so if you want that, just press enter. If you want half cosine spacing, click Half. Notice that Half now displays as HalfToggle. When you half cosine space, one end of your curve is tightly clustered with points, the other is much more spread out. HalfToggle allows you to have the clustered points at either the curve start or the curve end. If you simply hit enter now, the command would half cosine space a curve with the tightly clustered points at the curve start. Not sure where your curve start is? Esc out of the command, use the dir command to see where your curve starts. I never use HalfToggle personally, I always check the dir of my curves before I run CosSpacing.
Okay, well now that we’ve made it past that, the rest is easy. Just pick any curve, and it will be cosine spaced per your settings. If you need to change the settings, like say from half to full, then you need to esc out of the command and the restart it.
Ready to cosine space your airfoils? Okay, you can download the cosine spacing plugin for Rhino3D here.