Roland Melkert Wrote:I basically started implementing my thoughts as described here:
http://forums.ldraw.org/showthread.php?t...73#pid8173
It's using 4 different shape describing meta's at the moment, and some additional support ones (like include and reset). I'll probably have to add one or two more for the very exclusive part shapes.
I think I understand what your direction and design goal is, but let me ask a few questions to see if I fully get it.
- Sergio's system is based on "type matching" - a bunch of connection types are defined (strictly via data) and a much smaller number of geometries. Geometry matches must also match type to connect.
- In your system, it's all geometry, and the matches are strictly geometric. In other words, ALL cylinders of the same radius are going to fit equally well into a hole of the same radius.
Is that correct?
And if I understand: every geometric type that we find in the LDraw world will have to be supported by some geometry primitive that is built into the spec. In other words, the fact that your example is part cylinder, part axle works because both cylinders and axles are native to your code. If we ever have a part with a new, different cross section (where the axle's cross section is not a + shape) we'll possibly need a new geometry primitive and spec extensions.
Also, how would you handle pins? A pin is a cylinder with a wide rim - it only fits into the technic brick hole (a cylinder hole with a wider hole at the edge) because it can be compressed. It effectively provides one degree of rotational freedom once it is snapped in, although it has longitudinal movement freedom (and a lot of friction) while it is being inserted into the hole.
Cheers
Ben