| 02:43.05 | *** join/#brlcad llew (~llew@adsl-69-227-153-5.dsl.renocs.nvbell.net) |
| 02:45.59 | llew | new |
| 02:52.24 | *** join/#brlcad llew (~llew@adsl-69-227-153-5.dsl.renocs.nvbell.net) |
| 05:42.39 | *** part/#brlcad narnia (~terrylr@johann.blauedonau.com) |
| 05:56.36 | *** join/#brlcad narnia (~terrylr@johann.blauedonau.com) |
| 17:57.44 | *** join/#brlcad CIA-3 (~CIA@flapjack.navi.cx) |
| 18:48.51 | narnia | would someone be able to give me an example where a degenerate toroidal surface is used? by degenerate toroidal surface major-radius < minor-radius. |
| 19:30.47 | brlcad | what do you mean by used? |
| 19:31.05 | brlcad | you shouldn't use degenerate toroidal surfaces |
| 19:31.11 | brlcad | they're effectively "inside-out" |
| 19:32.45 | brlcad | unless if you're referring to super toroidal geometry, where one side of the torus is "pinched" to a point |
| 19:33.57 | brlcad | brl-cad won't let you make the inside-out kind, and I supertoroids aren't implemented (superellipsoids are, but they're unfinished) |
| 19:52.11 | narnia | ap203 has an entity degenerate_toroidal_surface ( as described above ) i am attempting to figure out how to map it to brl-cad. |
| 19:52.38 | narnia | i take it from your comments above it should not be mapped. |
| 19:57.28 | narnia | there are two cases: if major_radius == 0 and minor_radius > 0 the torus has no hole. |
| 19:59.14 | narnia | the 2nd case is: if the major_radius > 0 and major_radius < minor_radius. in this case the torus is self-intersecting. |
| 20:45.18 | brlcad | not exactly self-intersecting.. it's inside out per the definition |
| 20:45.45 | brlcad | if that's the input, I'd swap them on import so that it's corrected |
| 20:47.46 | brlcad | a zero radius is also not supported -- it's mathematically undefined for the equation of a torus |
| 20:48.35 | brlcad | there are several things that could be done with a zero-radius -- brl-cad's raytrace will abort on that degeneracy since, like I said, it's undefined |
| 20:50.21 | brlcad | but, I suppose you could either nudge it to a near-zero value (like 0.00001) or import as two objects (a torus with a central cylinder to fill the hole, for example) |
| 20:51.24 | brlcad | ahh, i see what you probably mean by the intersecting.. minor_radius can either be the radius of the "roll" or the radius from the center to the roll's edge, if it's the latter it's inside out, if it's the prior, it's intersecting |
| 20:52.27 | brlcad | I'd have to check what we do for the self-intersecting case, but I expect it would abort saying something like "boo" |
| 23:15.53 | *** join/#brlcad narnia (~terrylr@johann.blauedonau.com) |
| 23:17.38 | narnia | johann crashed. i thought for a moment i lost a scsi disk but i doubled check everything and johann appears to be fine. johann, was up 161 days before the crash. perhaps he just wanted a break or some attention. |
| 23:20.14 | *** join/#brlcad PrezKennedy (~Matthew@130.85.253.237) |
| 23:44.56 | brlcad | poor johann |
| 23:45.08 | brlcad | johann the barbarian |
| 23:55.55 | narnia | okay back to degenerate toroidal surfaces. |
| 23:56.39 | narnia | do you understand what i mean when i say the torus insects itself? |
| 23:56.53 | narnia | do you understand what i mean when i say the torus intersects itself? |