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PODraw a sphere using 3D pixels (voxels)
 

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    <p>Can you suggest an algorithm that can draw a sphere in 3D space using only the basic <code>plot(x,y,z)</code> primitive (which would draw a single voxel)?</p> <p>I was hoping for something similar to <a href="http://en.wikipedia.org/wiki/Midpoint_circle_algorithm" rel="noreferrer">Bresenham's circle algorithm</a>, but for 3D instead of 2D.</p> <p>FYI, I'm working on a hardware project that is a low-res 3D display using a 3-dimensional matrix of LEDs, so I need to actually draw a sphere, not just a 2D projection (i.e. circle).</p> <p>The project is very similar to this:</p> <p><img src="https://i.stack.imgur.com/TgOAv.jpg" alt="3D LED cube"></p> <p>... or see it in action <a href="http://www.youtube.com/watch?v=6mXM-oGggrM" rel="noreferrer" title="LED cube">here</a>.</p> <p>One possibility I have in mind is this: </p> <ul> <li>calculate the Y coordinates of the poles (given the radius) (for a sphere centered in the origin, these would be <code>-r</code> and <code>+r</code>)</li> <li>slice the sphere: for each horizontal plane <code>p</code><sub>i</sub> between these coordinates, calculate the radius of the circle obtained by intersecting said plane with the sphere => <code>r</code><sub>i</sub>.</li> <li>draw the actual circle of radius <code>r</code><sub>i</sub> on plane <code>p</code><sub>i</sub> using Bresenham's algorithm.</li> </ul> <p>FWIW, I'm using a <a href="http://www.ghielectronics.com/catalog/product/256" rel="noreferrer">.NET micro-framework microprocessor</a>, so programming is C#, but I don't need answers to be in C#.</p>
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    1. COJudging by the LED sphere should we assume you need the interior of the sphere plotted as well somehow?
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    2. CO@NominSim I don't think so. In this case he wouldn't talk about Bresenham's circle rasterization and could just use japreiss' brute force solution.
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    3. CO@Christian Actually, I would like to have both options.
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