Jun 222014
 

This post is part of a meta-series. Click here for a list of all posts in this series.

To be honest, part of me feels like this is cheating. My original objective was to do an accurate helmet but inexpensively (Blender being free and all, and everything else being mostly household/hardware store commodities easily and cheaply obtained). In some respects, I feel like I’m betraying that original goal in the interest of improving accuracy. But…new toy!

In other news, here’s the result of the second test run!

It’s much better, but still not quite right. The curvature is definitely right, thanks to the linear colorspace change, but I’m still having issues with the pieces not matching up (most notable in this image around the the “jowls”).

After a bunch of googling, comparing my heightmaps with the interpretation in the Designer software, and then looking at the result, I think the “problem” lies between the Designer software and the machine itself. Specifically, I think the machine is disregarding certain levels of black/white and just considering them flat, when in fact they should be subtly curved. This may be the result of using “Draft” quality and images where “1,1,1” and “0,0,0” color differences are really important. For example, look at the third “slice” up from the table: there’s a flat area around the bridge of the nose here that should not be flat at all. It’s not flat on my model, in my heightmaps, or in the Designer software’s 3D preview, yet it came out flat.

My next test will just be two pieces, but at a much higher quality setting, to see if this hypothesis proves true or if it’s something else after all.

Jun 222014
 

This post is part of a meta-series. Click here for a list of all posts in this series.

A friend of mine is moving out of state and needed to downsize the amount of stuff she had to move. Among the assets in question was a CNC router…which she sold to me!

Instead of manually cutting the cross-sections, I now can actually send the true cross-sections to the CNC machine and “print” out slices that I would have sanded into shape by hand previously.

Here’s the result of the first test run!

I realized that I had saved everything with non-linear colorspace, and when you’re doing stuff with heightmaps, non-linear colorspace screws up your curves and so on! Based on what I learned from this test, I’m now preparing to do a test with slightly adjusted positioning for the cross-sections…and proper linear color space data!