Nekochan Net

I don't know if the title is enough clear, so I'll expand the subject to some extents.

Well, over the past years I've spent more time coding some apps than operating third party softwares. But sometimes things reach an end, and thus happened with this. It seems that my new kind of work demmands exactly the opposite, and I miss a bit of practice with a few things.

One of these things is Blue-Prints. Let me explain it better: -let's say I'm modelling a given product by using ArtOfIllusion or BlenderCAD, and everything goes smoothly... I have the results just as I like, and all the rest. Then, let's say I want to print some relevant views from the plains, and then I just got all kind of superfluous lines... the kind of auxiliar lines that you get from several apps when "they try to show you better" the surfaces from a boolean object... and things like that... you know, the plain looks awfully nasty, and you can't reckon what is really relevant for mechanizing and the rest of processes.

So... let's say I want just the wires-model... how to clean it properly for print out to paper? I'm pretty sure there is probably some viewer, at the very best style from LX-Viewer (which is used for DXF/DWG AutoCAD projects) or something like that; but I fail to find one! Maybe I'm missing some option from AOI, or BlenderCAD?

Then, how to remove -just for print work- all of thoses nasty lines, to just keep the relevant contours? I hope some CAD-awared master here will help me a bit!
All the best,
Diego

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Octane / Dual Head

http://twitter.com/GeekTronixShop

I think you're running into a problem which is a fundamental difference between a CAD package (Pro/ENGINEER, Solidworks) and a 3D modelling package (Maya, 3DS Max). You're issue is trivially simple to fix on any real CAD program - you need to set "Hidden Line Removal" (there are a couple of options for this usually, as well as fast/quality settings for your display) and some options for the display of tangent edge intersections. 3D modelling packages aren't normally used to print blueprints to paper and probably don't have these options (but I'm not a user of them, so hard to tell). I would think your best bet is to export them in a compatible format (likely DXF/DWG, but I'd use STEP or IGES if you can. Actually I'm not sure DXF/DWG will preserve the surface data you need, they might not work.) to a real CAD application. Unfortunately, the open source/free CAD programs I know of are all 2D (QCAD), and you need a 3D application. I've only used higher end packages, but there are some relatively inexpensive packages (TurboCAD? something like that...) that retail for $150, $200 or so that might meet your needs for import/print.

FWIW, making prints has always been one of the weaker points of even 3D CAD programs. My old favorite CAD modelling program, I-DEAS, used to have a completely different program for drawings. You'd have this wonderful model, then you'd click an icon to set up the views, then BOOM, IDEAS would shut down, and then this shitty drawing program would start up with a completely different user interface, and yes, you'd have to muck around a bit with the hidden lines. I hope they fixed that at some point - I haven't used it in more than 10 years. Modern programs are much better. And IDEAS is dead.

Thanks dc_v01!, your post is extremely insightful, very useful for me! ...at least now I know I'm not the only one!

Now that you mention "Hidden Line Removal", this sentence sounds familiar for me, either from some programming libraries to help OpenGL with extended primitives, and things like that. I also seem to recall, ages ago when used to try 3DSMax, it had something like that.

To get back on-topic, it seems there are no cheap userland solutions either for IRIX or LINUX to help on this subject... right? It seems TurboCAD only runs with Windows/MacOSX.

An hour ago I've tried to set the BlenderCAD render engine to use Toon Edge Enhance, to increase the contour detail from perspective viewport. It works amazingly well for some models, more specifically if you set the textures to null and materials to a neutral gray color; but again, it does not solves my problem. It only makes a few more lookable either global or exploded views.

I'll take a look at BlenderCAD to see if there is no chance to remove hidden lines. You know, BlenderCAD is a just blender with a set of plugins/patchs to help a bit with some tasks... but this is what I have now!

For this time I'll be able to bypass the problem, but I'll have to search for a real solution here... all the best,
Diego

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Octane / Dual Head

http://twitter.com/GeekTronixShop

Yes, people who could afford SGIs usually could afford to pay for software, so no low cost alternatives. Open source doesn't seem to have made a 3D CAD application yet, only 2D. The only 3D apps are modeling apps like Blender.


Yep, this is a characteristic of viewing a 3D model. CAD apps let you put "views" to "paper" for making drawings. And you start to deal with "lineweights" or even "pens" - back to the good old pen plotters of the old days, still supported! (Even though everyone uses inkjets now!)


I wasn't familier with it, I thought you were just referring to the modeling interface of Blender...

Yes, it sounds pretty logical. After all, the independant professional, hobbyist, or alone single user who has bought a machine through eBay or any equivalent shop site is a bit of a stowaway on SGI-Land!



I guess you're right... but perhaps would worth the pain to take another look at it, since there are frequently "hidden" FOSS projects, that one seem to discover sporadically... or well, maybe I'm only wishing it...



Yes, my brother-in-law used to work with such kind of apps back on the days of MS-DOS... but I do not had interest for CAD on these days, only for 3D/Animation, Programming, etc... until now! ...and I don't like either learn/use AutoCAD! ...I just want... ehrrr... something else!



If you have the time, take a look here. You wont regret. It is pretty interesting:

Extensions:Py/Scripts/Manual/CAD
Extensions:Py/Scripts/Manual/CAD/BlenderCAD

Of course, I guess compared to a real CAD app, it could look as a toyware... and this is probably right, but has some real usefulness too.

This one should be pretty new too, since it was not there when I've installed the rest:

Extensions:Py/Scripts/Manual/CAD/ProCAD

...but it seems to be oriented to architecture of buildings?
Anyway, I'll take a deeper look on next hours, to see if there is something new from any FOSS movement.

Have fun!
Diego

_________________
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Octane / Dual Head

http://twitter.com/GeekTronixShop

Here are a few of my more interesting findings for "Open Source CAD 3D" keywords on Google... of course, most part of them are only 2D, but still interesting:

Archimedes

Art Of Illusion (I'm already using it...)

avoCADo (It needs way more development, but looks promising!)

BRL-CAD (It looks extremely useful, albeit a bit difficult to learn for me! ...maybe I should take the challenge some day?)

CoCreate (Killer app, but only available for MS Windows flavours...)

freeCAD (Powerful for real world mechanical/physical simulator... but for modelling, I feel as if I were operating my computer with boxing gloves!)

Free-CAD (This one looks friendly, and can handle many file formats... I like it... this thing seems to be what I would need... so I could want to see more progress... anyway, it is already added to my toolchain!)

FreeCAD.Com (A database of apps for many platforms.)

FREEdraft

Free Mechanical Engineering CAD Software (Very useful summary of apps!)

Google SketchUp (Not a FOSS app, I guess?)

GraphiteOne CAD (Supported for several OS, try-out version available but for commerical use requires licensing... only problem: downloads are disabled!)

lignumCAD (Wood working oriented)

Open CASCADE (This one seems to be "THE THING"; I've downloaded it... but not tried yet!)

Open Source CAD Applications (Another list, this one shorter.)

...Lego?

BlockCAD

...and some others, perhaps more related with EDA:

TinyCAD

Let me know your findings!
Diego

EDIT: ...I'll probably add more to the list as soon as I get more relevant info; and of course I'll try (albeit slowly) all of them.

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Octane / Dual Head

http://twitter.com/GeekTronixShop

What kind of Blue-Prints are you working with?

Do you require 3D CAD? Many 2D CAD programs have primitive 3D drawing tools for drawing in perspective and creating isometric views.

Thanks for the software lists, Diego, there's some I'd not seen there before!
BRL-CAD exists for IRIX (maybe only the older versions, haven't looked in a while) but unfortunately I think they focused on modeling as well, and there isn't much/any drawing support. That's just my impression, though, I've never used it. The FreeCAD software looked interesting - it's new, can't tell if the drawing package is working yet, but at least they're planning on it. Of course, win/linux only - but don't you have some mad C++ skillzz? Maybe you want to tackle an IRIX port?


I think the issue is he already has the stuff modeled in BlenderCAD that he probably doesn't want to start over - and if you've been doing 3D, would you really want to go back to 2D even if it works?

Well... it is not as I require 3D CAD, it is just I feel more comfortable dealing with 3D primitives, you know. But hey, I guess I'm open to try something different if it works... so, what do you suggest?

I'm using Art Of Illusion and BlenderCAD to model some little CNC Machines, and al sort of electronic equipments for automation, and on a last case, audio.

_________________
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Octane / Dual Head

http://twitter.com/GeekTronixShop

I love to do lists!, you know!
...same here: I've noticed a few different beasts since my last time!



Yes, I have it installed on my Octane I think... but there was something (I can't recall what!) that pushed me away from it in favour of BlenderCAD, and from BlenderCAD in favour of Art Of Illusion, oh well... I was recently pushed to learn too many apps!



Never tried it! ...I should install it here!



Well, I should make me a bit of time some day to launch a few MIPSPRO sessions... it seems it was a century ago since my latest one!



You're right... because I'm used to model a lot by using booleans, and extrudings... so, I guess I would feel a bit limited with 2D. But if it solves my problem with drawings... I guess it would worth the pain... is there any FOSS 2D CAD to try out with IRIX or LINUX?

In example, here is how it looks a perspective rendered by BlenderCAD, by using Toon Edge Enhance. Without any materials/textures it would look way better, and at least you can print a perspective view without background, by using Alpha Channel. The toon edge was increased to make it more evident:



Right now, I'm just using a different camera for each view (front, rear, top, bottom, left, right, etc...) then I can get a full set of views. But it is not the best way to do it, you know it, I know it...

It will generate a cool looking set of views, but it will hidde many relevant details, so you'll need to set up a few extra cams to get inside the models, so you can catch extra details. At least I already develop a method to avoid the distorted perspective from the virtual camera lenses for each view, so I get a pretty neat drawing. As I said, I'm actually about to complete a new CNC Router, which in fact I'm building right at this moment too! ...so, feel free to indulge my above pict, but it is just a sample

_________________
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Octane / Dual Head

http://twitter.com/GeekTronixShop

I am using ProCAD+ on my Risc PC for making drawings. It is not free, and there are only RISC OS and Windows versions available. But it is low cost, has very good support from the author and has very powerful drawing tools.

One of my favourite tools is Isometric group copy. You can draw group of objects from top-down view and then copy it to Isometric perspective. After that you can use extrude to create similar objects like in your example picture.

I will create a little demonstration later in the weekend.

Hate to be a spoilsport but ... all the fossy bitch cad programs are not ready for prime time ... there's one or two that look like they may have possibilities but they just aren't there yet. In fact, from the looks of the interfaces they'll never get there.

Pretty sure Blender will export in dxf.

I would personally hunt for a copy of Cadkey 7 for DOS on fleabay or elsewhere. Should be very cheap. It was the best wireframe 3D cad program ever and I think you could get it to run in Softwindows. You could import your dxf's from Blender into Cadkey and print from there. Or set up an OS/2 box, it runs great in a VDM.

It's also very nice to use on its own but different from the current solid modelling paradigm. With a wireframe app you draw edges and connect them, with most solids programs you throw a blob onto the screen and constrain it. Different thought pattern.

But all CAD programs use real numbers instead of that pull-it push-it approach that you artiste types like. Yuck, artists ! How the hell can you know how big anything is that way ?

Hehe, good point. But in certain 3D programs you always work with real numbers regarding of what your "Grid units" are set to, and it's the only way to work in if you get used to it. Luxology's Modo comes to mind. It always displays where you are "number wise" from world origin using your mouse pointer. And of course, every primitive you create, is set with real world numbers.

Both Maya and XSI are using arbitrary numbers instead, since it uses it's grid as a measuring "tool". If you tell XSI that every grid unit is 1cm, that is what you work with. And that work well too. But I sure prefer Modo's way of displaying numbers, since you always know exactly where you are number wise.


/Jonas

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Old polygon wrangler
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Oh, yeap, I know what you mean hamei (and sgtprobe); this is one of the many things to sort out when you use a 3D/Animation app for CAD use.

That was my first problem with BlenderCAD, then I've noticed if you press "N" while you have an object selected, you can input numerically all the required parameters... the problem is... if you have "Dim X: 11.964" the programme does not knows if those are 11.964 mils or 11.964 yards... heheh! ...then you set the grid accordingly, and things get more consistent if you take careful note from the scale values, and so on... but at least it will export to DXF (and another myriad of scene descriptors and formats!) if needed.

With Art Of Illusion, things are a bit different, but not so much. You always get numerical info from the selected object, but the problem is: it does not reckons correctly the booleans! ....so you need to measure them with another auxiliar object used as a rule. This one only exports to OBJ (Wavefront), POV (POVRay), and VRML.

So, as you can see... I'm not getting all that help from my computer right at this moment... of course she likes to be more collaborative, but... my tools are not the required ones!

All in all, I've managed to get fairly good results from both tools lately, but spending way more time than necessary... yes. Another thing is, I don't know how precisely would be exported my models from both apps... but at least an OBJ from AOI to BlenderCAD worked fine (but not the reverse way, at least for me)

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Octane / Dual Head

http://twitter.com/GeekTronixShop

A wireframe app would still be a bit of a headache, though, in the sense that you would still need to manually clean up all your hidden lines to display how you want them, wouldn't you? Or does .dxf/.dwg preserve some surface data that would allow automatic hidden line processing? That's why I was recommending STEP, to preserve the surface data. The last time I did any wireframe it was the mid'90s or so, maybe AutoCAD 12, I don't remember a thing...