irclog2html for #brlcad on 20050227

00:30.28 jano gnop
03:21.39 PrezKennedy ding
03:47.06 jano gnod
03:47.40 danfalck ok....tell me about brlcad
03:51.46 jano well.. he's male, late twenties, likes to program
03:54.50 danfalck do you use the brlcad application?
04:00.30 jano sorry, I haven't used it in a long time
04:00.42 jano it's essentially a cad program
04:00.48 jano that mainly uses CSG for modelling
04:02.31 danfalck are there a lot of programmers working on it?
04:06.19 danfalck is it a project with a lot of potential?
04:06.39 danfalck I'm interested in o/s cad/cam
04:06.54 jano it's used by the government if that means anything to you
04:07.04 danfalck I do tooling design/drafting and some CNC programming
04:07.15 jano best would be to talk to brlcad when he wakes up
04:07.21 danfalck ok. thanks
04:07.25 jano hmm
04:07.44 jano i dunno if he's awake
04:07.55 brlcad i'm here.. gimmie a secd
04:08.00 jano :)
04:08.04 danfalck hi
04:08.11 danfalck thanks jano
04:31.23 brlcad sorry about that danfalck .. was away in the middle of something
04:31.27 brlcad what would you like to know?
04:32.33 brlcad BRL-CAD is a solid modeling system
04:33.16 brlcad includes a csg-based modeler, several raytracers, lots of geometry import/export controls, some animation and procedural geometry support
04:33.38 brlcad for developers it gets even better, with a couple dozen isolated libraries
04:33.48 danfalck you invited us over from the #emc irc channel.
04:33.59 danfalck I'm into drafting/tool design and CNC programming
04:34.12 brlcad ahh, I thought your name was familiar
04:34.26 danfalck I'm interested in open source cad/cam
04:34.28 brlcad i think narnia mentioned you too
04:34.59 danfalck would brlcad be useful, at some point, in outputting g-code?
04:35.15 brlcad at some point, yes -- definitely
04:35.28 danfalck ok, good
04:35.34 brlcad in fact I believe that's specifically one of narnia's goals to get working
04:35.56 danfalck what have you been able to do with brlcad so far?
04:36.19 brlcad brl-cad is used extensively by the gov't for ballistics and vulnerability analyses
04:36.52 brlcad e.g. there's a complete brl-cad model of pretty much any tank in existance
04:37.04 danfalck ok. do you have it working on your computer?
04:37.07 brlcad down to the wires, fuel lines, etc
04:37.35 brlcad heh, yes, it works on my computer
04:37.39 brlcad and lots of others ;)
04:38.01 danfalck ok. I've been looking at the web site and just started skimming the mged tutorial
04:38.02 brlcad it's pretty cross-platform -- weakest link is probably windows
04:38.15 danfalck I don't need Micro$oft
04:38.21 brlcad mged is one of 400 tools, albeit the one that gets most of the attention
04:38.35 brlcad i'm not that fond of it myself, but it is in widespread use in the gov't
04:39.44 danfalck are you a draftsman or computer programmer?
04:40.20 brlcad my primary hat is that of a computer scientist
04:40.46 danfalck have you been working with it for a long time?
04:41.00 brlcad software design, graphics, AI
04:42.13 danfalck sorry for all the questions. I'm trying to get a feel for what's happening with the project now.
04:43.39 danfalck I have looked at it in the past but always avoided it because of the non-gpl license. But that's changed
04:45.07 brlcad no problem
04:45.40 brlcad been working with brl-cad for about 7 years, computer programming for about 20
04:45.49 danfalck great
04:46.28 brlcad most of the other/older brl-cad devs are at earshot too
04:47.45 danfalck I see lots of references to CSG. Can it do other things like draw profiles and extrude too?
04:49.02 brlcad yes
04:49.07 danfalck great
04:49.12 brlcad there are various "primitive shapes" in brlcad
04:49.31 brlcad one of them is a "sketch" .. which is basically a common 2d drawing
04:49.37 danfalck good
04:49.40 brlcad that may be extruded to become a solid model
04:50.07 danfalck I'm thinking in terms of drawing pockets to be milled out
04:50.15 danfalck or engraving on a surface
04:50.15 brlcad there are also extruded bitmaps and a couple other similar 2d constructs
04:51.28 danfalck or maybe even turned applications
04:51.47 danfalck I've always got CNC on the brain
04:52.51 danfalck what's the base machine right now for running the application on Linux?
04:52.54 brlcad I'll need to read up more on g-code and cnc formats as that's admitedly outside of my field of experience to date
04:53.08 brlcad base machine?
04:53.30 brlcad if it doesn't work, it's a bug or limitation of the new build system
04:53.33 danfalck I have a 500 mhz AMD box here
04:53.50 danfalck lowest class of computer...
04:54.19 danfalck or I should say, minimum requirements
04:54.50 brlcad there's not really minimum requirements, unless you're familiar with old machines like a gould 9000 or a vax 11/780
04:55.09 danfalck ok.
04:55.26 brlcad it'll just be a function of your model size
04:55.37 danfalck thanks
04:55.52 danfalck G-code isn't really complicated
04:55.58 brlcad that's source code though -- there are implicit limitations on the posted binaries
04:56.04 danfalck it's just lines and arcs
04:57.15 brlcad e.g. the binaries are linked against opengl .. so massaging (or recompiling) is needed for non-opengl
04:57.28 brlcad lines and arcs are pretty simple
04:57.59 brlcad could probably make a sketch -> g-code converter easily enough
04:58.12 danfalck I'm learning python right now. Using simple drawing programs to study
04:58.14 brlcad but more useful would probably be an arbitrary plane cross section to g-code
05:01.26 brlcad what kind of views are usually significant for cnc machines?
05:01.53 brlcad does it genearlly work on fixed orthogonal planar projection outlines?
05:02.06 brlcad or are they arbitrary?
05:02.25 danfalck It depends on the work you want to do. Basic milling can be done while looking at 2D view
05:02.55 danfalck but it's nice to have ortho view to see where the end mill(tool bit) is plunging or going back up
05:03.14 brlcad 2d milling is assumedly from a model that was modeled in 2d usually no?
05:03.23 danfalck yes
05:03.30 brlcad on the same plane even
05:03.36 danfalck yes
05:03.56 brlcad what about 3d milling?
05:04.00 danfalck but if you are doing multiple depth passes, it's nice to see where the tool is going
05:04.16 danfalck for surfacing (3d milling) ortho views are a must
05:04.34 danfalck for lathe work 2d is just fine
05:04.40 brlcad hmm.. multiple depths .. how's that generally work in the modeling software?
05:05.03 danfalck well in commercial cam software, you start with a profile
05:05.17 danfalck select the direction of the tool path
05:05.30 danfalck by clicking on the profile geometry on the screen
05:05.52 danfalck and changing the direction of arrows on the profile path
05:05.54 brlcad and it output's "slices" to mill
05:06.10 brlcad s/slices/depths/
05:06.13 danfalck then you fill in a dialog box telling the app depth, etc
05:07.19 danfalck so simple profiles, with dialog boxes, then an editor popping up with G-code for the user to examine
05:07.55 danfalck It could really be done with a fairly simple program, which I would like to learn how to program
05:08.11 danfalck so, I'm playing with some python cad apps
05:08.24 brlcad say I have a circle 2d model that I want for 3d milling?
05:08.36 brlcad like I want to mill a half sphere
05:08.41 brlcad how would that work?
05:08.58 danfalck well then I guess it gets more complicated
05:09.29 danfalck I have seen "waterline" machining strategy where the tool goes around the part in the same plane
05:09.39 danfalck then moves down to the next depth
05:09.55 brlcad i can imagine how the machine itself does it :)
05:09.55 danfalck and does the same thing again at the larger diameter
05:10.12 danfalck there are zigzap strategies
05:10.14 brlcad how do the commercial modelers do that? :)
05:10.41 danfalck surfaces are selected
05:11.02 danfalck the app projects some sort of mesh over the surface
05:11.20 danfalck that is supposed to project the toolpath
05:11.38 danfalck without gouging into the part (tool tips have to be considered)
05:12.14 danfalck I've done guitar necks using Smartcam a few years ago
05:12.33 danfalck and we used a strategy that ran the cutter along the length of the neck
05:12.50 danfalck moving to a different Z depth every pass
05:13.03 danfalck we used a ball end mill
05:13.04 brlcad right.. but how did you tell the software to do that?
05:13.15 brlcad i presume you modeled the neck in 3d
05:13.25 danfalck yes, with ACAD, Rhino
05:13.44 brlcad ACAD or autocad?
05:13.52 danfalck Autocad
05:13.54 brlcad ahh
05:14.09 brlcad (there's another cad package called acad)
05:14.12 danfalck oh
05:14.29 danfalck Now I work in a shop that does mostly turning
05:14.39 danfalck and it's a whole different ball game
05:14.53 danfalck I program by hand...
05:15.24 brlcad so now once you have the model imported from your cad package, how did you go about telling the software what you wanted to do?
05:15.38 brlcad milling-wise
05:15.49 danfalck the model imported in as a lofted surface
05:16.07 brlcad ah, so that gave you a starting plane
05:16.20 danfalck so once it's in the CAM app, you end up selecting all the lofted arcs in sequence
05:16.34 danfalck then the app has an idea where to start from
05:16.52 brlcad were they linear lofts?
05:17.05 brlcad a guitar neck isn't linearly lofted in any dimension
05:17.27 danfalck well think of it as a series of arc in the YZ plane
05:17.45 danfalck sorry I'm not better at explaining it
05:18.04 brlcad better yet.. what was your model lofted from?
05:18.18 brlcad from the base/top of the neck? from the flat top surface?
05:18.20 danfalck I started by digitizing an existing model
05:18.46 danfalck layed the neck with the fretboard(flat surface) down
05:19.05 danfalck probed over the back from one side to the other
05:19.19 danfalck one YZ profile at a time
05:19.31 danfalck move in X .1" then do it again
05:19.43 brlcad so you modeled the parabolic curve for one slice?
05:20.26 danfalck I actually had to probe Jimmy Pages guitar neck and it was worn in spots
05:20.39 danfalck so we did the whole back of the neck
05:20.48 danfalck we didn't do the headstock
05:21.00 brlcad i'm asking, though .. how did you "do" that back of the neck
05:21.23 brlcad you have basically a long rectangle for starters
05:21.29 danfalck ok I see what you mean, I think
05:22.01 danfalck I ran the probe across the neck from side to side generating a roughly parabolic shape
05:22.26 danfalck probed slices .1" apart from each other.
05:22.32 brlcad no worries.. I can wander on over to a milling shop if need be :)
05:23.00 danfalck forming a series of profiles that remind one of the skeleton of a snake :)
05:23.02 brlcad or just talk to one of my friends that work for some of the cam companies
05:23.31 danfalck basic milling is a lot easier to deal with
05:23.36 brlcad okay, so sliced perpendicularly down the neck
05:23.42 danfalck yes
05:23.57 danfalck once the data is in the modelling/cad program
05:24.03 brlcad so you end up with a slew of parabolicish curves
05:24.09 danfalck yes
05:24.11 brlcad that end up forming the surface mesh
05:24.38 brlcad so when you brought that into the cam software
05:24.52 danfalck yes. But I didn't need to massage the surface much since I took so many readings
05:25.03 brlcad you told it to start with the long rectangular base as the starting face .. i.e. "the bottom"
05:25.16 danfalck yes
05:25.35 danfalck tell the cam app to start machining from one end or the other
05:25.49 danfalck give it the diameter of the ball end mill
05:26.04 brlcad then you selected each arc from smallest to large/widest for milling "down" the neck
05:26.44 danfalck With Smartcam, it could either loft the same way that I probed the part or it could generate lines perpendicular
05:26.54 danfalck to the original ones
05:27.19 danfalck I ended up machine it both ways to see which worked the best for finishing
05:27.27 brlcad so the tool bit is actually pointing down the guitar neck (parallel to the rectangular base) as opposed to pointing towards the front of the guitar
05:27.47 danfalck it was pointing toward the fron of the guitar
05:28.04 danfalck as if the guitar was laying on it's face
05:28.09 brlcad okay
05:28.30 danfalck we used a giant Komo router to do the first 50 necks for production
05:28.30 brlcad hm.. then the software must of had some sort of path interpolation
05:28.35 danfalck yes
05:28.45 brlcad to tell it how to mill smoothly across the slew of slice surfaces
05:29.01 danfalck yes it was really slick
05:29.16 danfalck multi thousand dollar package
05:29.37 danfalck it might have been 10k back then
05:29.51 danfalck Luckily I didn't have to buy it myself
05:30.19 danfalck I have a small garage shop for a hobby
05:30.44 danfalck and use Autocad , Rhino and a small cam package named Vector
05:30.57 danfalck I just want to do some small hobby stuff
05:31.03 jano ooo i remember rhino
05:31.11 jano what happened to them? they still around?
05:31.13 danfalck I used to do lots of engraving with Vector
05:31.27 danfalck rhino is still very popular
05:31.30 jano hmm
05:31.42 jano for what.. cad stuff or ?
05:31.46 danfalck yes
05:31.48 jano ah
05:32.00 danfalck jewelry industry uses it a lot
05:32.06 jano there's this other program out now that seems to have amazing results for other 3d
05:33.02 danfalck I hear that a lot of people use Solidworks
05:33.16 danfalck We just purchase ProE at work. Haven't used it yet
05:33.25 jano it was a program used by the dudes that did LoTR
05:33.43 danfalck But, I'm more interested in open source stuff because I like to tinker
05:33.47 jano yah
05:34.55 danfalck brb
05:37.42 danfalck ok
05:42.18 danfalck I need to go. I'll be monitoring this channel from now on. Good talking with you guys.
06:14.02 brlcad same to you
06:14.20 brlcad yeah, most commercial cad packages are several thousand dollars
06:14.41 brlcad heck even brl-cad has had millions of dollars invested in it
06:18.00 brlcad that's what's made brl-cad's open sourcing so mutually hopeful
10:06.40 *** join/#brlcad Pimpinella (~frank@p50821131.dip0.t-ipconnect.de)
15:56.40 danfalck morning
16:29.51 brlcad mornin
16:40.44 danfalck can brlcad do any work on meshes?
16:40.54 danfalck or export them?
16:41.52 brlcad yes
16:42.45 brlcad brl-cad deals with triangles via BoT (Bag of Triangles) and NMG (generic non-manifold geometry) primitives
16:43.43 danfalck it looks like I need to install brlcad and explore it
16:44.45 brlcad by design, brl-cad prefers non-polygonalized geometry but there is a conversion path to triangles for any object/primitive
16:47.07 danfalck so if I wanted to get started, I should just grab the *tar file and start reading the mged (sp?) manual?
16:47.39 brlcad that would be reasonable :)
16:48.23 danfalck ok. I will do it.
16:49.02 danfalck I eventually want to set up a manufacturing system using o/s cad linked to EMC on my machines
16:49.09 danfalck in my garage
16:49.58 danfalck I own some cam stuff, but I have totally lost my appetite for closed source software
16:56.22 brlcad brl-cad's always been written in as "open" a development manner as was possible
16:57.04 brlcad it was only through significant persistance and a bit of luck that it was able to go open-source
16:58.20 brlcad but it does make complete sense for brl-cad's specific situation and history
16:58.21 jano does BoT come with a bonus set of monkeys in a barrel?
17:00.09 jano the sound you just heard was my joke doing mach 7 over your head
17:00.15 jano :D
17:00.42 jano Bag of Triangles, Barrel of Monkeys
17:02.29 brlcad dunno if he'd actually eat those
17:02.39 brlcad prolly
17:03.51 jano has it grown anymore?
17:04.30 danfalck so you mentioned that a lot of money went into the development of brlcad
17:04.34 danfalck millions?
17:14.44 brlcad consider that the package has been around for 20 years with constant funding, support, staff, training, improvements, etc
17:15.29 brlcad that doesn't necessarily mean that it's commercially viable or great for the general public's needs -- it was designed to efficiently perform a very specific set of tasks
17:15.40 brlcad and it does that _very_ well
17:16.48 brlcad but things like usability and user interface enhancements is something that gets handled as an afterthought as it's never funded
17:28.10 danfalck thanks for the info. I will install tonight. I'm going out for a walk.
17:28.36 brlcad have a good one
19:09.08 *** join/#brlcad narnia (~terrylr@johann.blauedonau.com)
19:25.01 PrezKennedy ding
19:53.09 narnia knock, knock, anyone home?
19:58.23 danfalck hi
19:58.31 danfalck narnia: hello
20:05.55 narnia danfalck, hello, how goes it?
20:06.30 danfalck ok
20:06.44 narnia danfalck, sorry, i was searching on google for some more info on the express language.
20:06.51 danfalck I have been quizzing brlcad about BRLCAD
20:07.06 narnia danfalck, that is good.
20:07.19 danfalck it sounds like a pretty heavy duty app with a lot of potential for what we would like it for
20:07.26 narnia danfalck, so what do you think so far?
20:07.53 narnia brb, need coffee.
20:08.05 danfalck narnia: well, I have just scratched the surface. It is kind of intimidating
20:10.22 danfalck narnia: but if you're into it, I am willing to try it out
20:10.37 danfalck brb-fixing sandwich for son
20:14.12 danfalck ok I'm back
20:14.33 narnia danfalck, i am here.
20:14.55 danfalck narnia: are you running brlcad now?
20:15.03 narnia yes.
20:15.20 danfalck what have you been able to do with it so far?
20:17.22 narnia mainly building models of past projects. exploring alternative methods of construction.
20:18.49 danfalck can one make a drawing w/ dimensions on it for presentation to a shop?
20:19.26 danfalck I see lots of references to 3d models and CSG, but wonder how deep it is.
20:20.21 narnia probably the best way would be to look at the brlcad manual and tutorial.
20:20.41 danfalck yes
20:20.51 danfalck mged manual
20:21.01 narnia yes
20:22.17 danfalck I have a Morphix based computer here, with EMC RC46 on it. I will see how much space I have left on it and install there.
20:22.41 danfalck I've got the manual on this OS X box now
20:23.46 narnia as in macos x?
20:25.08 danfalck yes
20:25.20 narnia imac or emac?
20:25.23 danfalck cube
20:25.33 narnia ah
20:25.41 danfalck very quiet and small
20:26.06 danfalck I can run a load of gnu apps on it using X11
20:26.28 narnia i have an imac and an emac. i would like to have a mac mini to play with. those look interesting.
20:26.49 danfalck same here. I would like one too.
20:28.12 narnia did brlcad happen to mention if he will be around today when you chatted with him?
20:28.47 danfalck he was around this morning about 8:00 am pacific time
20:33.55 narnia ah
20:34.09 narnia sorry was dealing with the puppy.
20:34.35 narnia i need to take him for a walk. i will be back later.
20:34.46 danfalck ok chat with you later
20:39.02 *** join/#brlcad jnc (shadow@macco.pimpcat.org)
20:39.05 jnc howdy
20:41.51 danfalck hello
20:50.58 jnc i'm thinking about writing up an ebuild, which would allow Gentoo Linux users to install brlcad
20:52.32 danfalck cool
20:53.03 danfalck I'm using a Morphix/Debian based distro
21:20.09 brlcad jnc: starseeker had put together and submitted an ebuild already
21:20.34 brlcad not sure where or how far he got, but he did help me track down a coupld sandbox problems that were fixed
21:21.39 brlcad jnc: http://bugs.gentoo.org/show_bug.cgi?id=77197
21:22.03 brlcad some things there I'd hope change, but it's a start
21:25.20 brlcad things like running on more than x86 -- i just decommisioned by ppc gentoo box, or I would be pressing that myself
21:26.53 brlcad a couple more concerns are fixed in the latest builds and will be in a new source/binary upload that should get posted this coming week

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