Here's a simple test program using LibQGLViewer (screen capture with xvidcap). The vertex array and the index array that OpenGL draws (using glDrawElements) are held in a GLData class which holds a mutex. The Viewer class locks the mutex while drawing, and the worker-thread locks the mutex while updating the data. Here the worker task [...]
Saturday, October 1, 2011
Based on Mark Pictor's cam-occ work I've been able to use the emc2 g-code interpreter 'rs274' binary that gets built during an emc2-build. It reads g-code files and outputs 'canonical' motion commands (see e.g. "The NIST RS274/NGC Interpreter - Version 3"). I'm positioning the tool at densely sampled points along each move, and subtracting it [...]
Sunday, September 25, 2011
I've looked at set-operations (union, difference, intersection) for octrees again. Previously I tried it with linear-octrees and visualization with python and VTK. Now I'm using a traditional pointer-based octree data-structure, and drawing with OpenGL VBOs. With the addition of a g-code interpreter, a user-interface, and an isosurface extraction algorithm (such as marching-cubes) this should converge [...]
Wednesday, August 18, 2010
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 [...]
Saturday, August 14, 2010
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 [...]
Wednesday, January 2, 2008
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 [...]
Saturday, December 1, 2007
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 [...]
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