Update: this figure shows the numbering of vertices(red), edges(green), and faces(blue). The arrows show the direction of the X-(red), Y-(green), and Z-axes(blue). Here the sides of the cube are not generated with Marching-Cubes, they are just extracted directly from the octree. Nodes are subdivided whenever the signed distance-field of the cutter indicates that the surface [...]

The speed of the new cutting-simulation code makes it possible to run it at a higher resolution than before. That makes the surfaces look smooth and nice. Alas, some problems still remain with holes in the fabric of reality mystically appearing and disappearing . There is an edge-flipping paper by Kobbelt et al. from 2001 which improves [...]

This is my second attempt at a machining simulation where a moving milling tool cuts away voxels from the stock material. To save space an octree data structure is used to store the voxels, and to produce a nice looking surface you store the signed distance to the exact surface in each vertex of the [...]

Update 3: this leads slowly towards a better and faster cutting simulation. Here’s an example with Tux: Update2: this looks slightly better now (a ball translated in a few steps towards the right). Image and c++ code by fellow OCLer Jiang from China. Update: in a cutting simulation the stock is updated by removing voxels [...]

Dan Egnor sent me this nice example of bitmap-based toolpath generation, or ‘pixel mowing’. It’s a slightly exaggerated topographic relief of San Francisco machined in tooling board using a very simple ‘lawn mowing’ toolpath generator. The explanation of how it works below is mostly Dan’s, not mine. This is the input to the toolpath generator [...]

Moving forward with the CAM coding, the sensible thing would probably be to work on mundane things like 2D offset generation, a kd-tree for faster drop-cutter searches, and zigzag-paths from 2D outlines… There’s again been some talk about open-source CAM on cnczone, but not much in terms of results or actual descriptions or implementations of [...]

Most conventional CAM algorithms are geometry-based. They create toolpaths that are usually parallel to either the coordinate axes (‘zigzag’-paths) or to the part contour (contour-parallel, or spiral paths). One problem with this geometry-based stuff is that you don’t take into account the cutting forces. The algorithm has no idea about how much material is removed [...]