Question CAD-like modeling request

[SolarStorm]

I've downloaded Anim8tor, Blender and even gmax to make the model, but that's where I get stuck. (I also downloaded orbiter shipyard, mesh wizard 1.9, spacecraft 3, etc but first I need a model to use them on.)
The problem mainly lies in the lack of accurate dimensions. I've had experience with CAD programs like AutoCAD and Inventor where you can easily define exact lengths and angles, whereas in Blender or Anim8tor, you pretty much have to model freehand or with a pixelated line drawing as a guide. I simply can't cope with that. I need exact dimensions to make an accurate model. Gmax keeps this in check somewhat, as you can input dimensions, but there are major modeling features missing that you would only find (I'd imagine) in a CAD program, like the "Loft through profiles" command, which is needed to make an accurate aerofoil (which I wish to do.)

In Inventor, you can actually export a model to .3ds format which I would do...except I don't own Inventor and it costs a lot. I've gone looking and I simply cannot find a free 3d modelling program that allows you to enter exact dimensions like you would in a CAD program, aside from gmax.
Does anyone know where I can find a free, CAD-like 3D modelling program that I can input accurate, numerical dimensions, and then export or save it to a .3ds format, or any format which I can then convert into a .msh - or am I seriously asking for too much?

 

[jedidia]

I am pretty convinced that you can enter dimensions numerically in Blender. I wouldn't have seen any serious modelingsoftware that doesn't support it, and Blender is about the most serious you can get without paying for.

 

[Hielor]

Wings3D allows you to input exact dimensions (to an extent--it's still designed more for freehand modeling, but the option is there to input exact dimensions for any operation if you hit the "tab" key).

There's also an [ame="http://www.orbithangar.com/searchid.php?ID=3901"]exporter[/ame] directly to the .msh format, which means that the model shows up in Orbiter with higher fidelity than if you go via 3ds2msh or obj2msh.

 

[simcosmos]

SolarSorm, not sure if understand the doubt about Anim8or (or Blender, etc) vs dimensions input / references: for example, you can make 3D models in Anim8or with accurate enough dimensions (numerical input for lengths, widths, heights, diameters, etc) and also define images to be used as background references... please see:

http://www.orbiter-forum.com/showpost.php?p=193632&postcount=10
(as mentioned in the previous posts above, the same is valid for Blender or other 3D editors)

Please note that I'm not saying that Anim8or is the most flexible / powerful 3D editor around but it is the tool I use for my models and it can certainly be used to produce 3D parts with accurate dimensions / shapes (including airfoils).

António

 

[michael_GR]

I've downloaded Anim8tor, Blender and even gmax to make the model, but that's where I get stuck. (I also downloaded orbiter shipyard, mesh wizard 1.9, spacecraft 3, etc but first I need a model to use them on.)
The problem mainly lies in the lack of accurate dimensions. I've had experience with CAD programs like AutoCAD and Inventor where you can easily define exact lengths and angles, whereas in Blender or Anim8tor, you pretty much have to model freehand or with a pixelated line drawing as a guide.

Seems like you r real problem is that you are not as familiar with those programs as you think. Blender does have numerical input. Gmax does have multi-profile lofting. You just need to learn how to accomplish those things.
Numerical input in blender - that depends on which version you use, the stable 2.49 or the development verison, 2.5.X. in 2.5 you just have to click the "+" sign in the top right of each 3d viewport to get access to make the properties panel visible. in 2.49 it's different, look for something with "properties" in the 3d viewport "view" menu.

As for lofting multiple profiles, here's a 3ds max tutorial on the "loft" command, probably also relevant to Gmax which is just 3ds max without rendering tools.
http://www.pawas.com/graphics/lofts-tutorials.htm

In blender the technique is called surface skinning and is described here:
http://wiki.blender.org/index.php/Doc:Manual/Modeling/Surfaces/Skinning

 

[SolarStorm]

Hielor: I'll check out wings3D and see if that helps.

michael_GR: I'm using v2.49b, and I looked in 'view -> view properties...' but that only seems to adjust the grid, camera, 3d cursor, etc but I that probably just means I'm not looking hard enough. Also thanks for the links (though I've never heard of lofting being called skinning before:lol

simcosmos: That is exactly the kind of thread I was looking for before posting this one:facepalm: This Usonion guy is one after my own heart, though (it appears) significantly older. He's right. AutoCAD doesn't just give you the mouse cursor and the graphical interface, but you also have a console to give either the exact or relative Cartesian coordinates (among other commands) to create the shape(s). Also, in (all?) CAD systems, you can click and drag a dimensioning tool to measure a diameter, a radius or any two points. After that, you double click, enter a different number and the dimension readjusts.
In all these programs, except gmax, (and maybe wings3d?) these tools are not readily apparent or available, so many people with CAD experience (such as myself and Usonion) are quite understandably baffled.

EDIT: I've checked again and I still can't find anywhere where I can input exact geometric dimensions in anim8tor or blender.

 

[Rybec]

For numerical input in Blender, you can just use the keyboard shortcuts for your actions, then type in the amount.
The key commands are:
-g-rab (translate)
-r-otate
-s-cale

You can choose an axis to manipulate on by typing it: X, Y, Z.
Then, just type the amount.
So, to translate something 0.35 units on the X axis, select it and press G, X, 0.35.
When scaling, the numerical value is the multiple of current size, i.e. 1 is no change. Rotation is in degrees, but you might be able to switch it to radians somehow if you need to.

For more advanced freehand manipulation, pressing these buttons also lets you use the mouse to manipulate, without having to click/drag. You can still lock to an axis. You can also lock to two axises at once, by excluding one with Shift-(axis). So, to move on X and Y: hit G, Shift-Z. When freehanding, you can hold Ctrl to snap to the grid at whatever smallest scale is currently visible, and you can hold Shift to reduce the effect of your mouse movements for greater accuracy.

If you want to enter a definite global position instead of typing in a relative manipulation, press n in the 3D view to bring up a little properties window that displays/edits such things.

Once you get used to it, Blender does pretty much whatever you want with little hassle. It's learning curve is steep at first, but flattens out fairly quick. Especially if all you're doing is modeling.

That said, things like a CAD system's auto-redimensioning aren't present, though depending on what exactly you're trying to do it can be emulated.


It's also worth mentioning that Blender can import a DXF file. Also, won't AutoCAD export an OBJ? You could do most of your work in CAD, then bring it into Blender for texturing and materials. There also appear to be some scripts available that add CAD functionality to Blender, I'm investigating that now and I'll let you know what I find.


EDIT:
Okay, I've found a couple different script resources. One will allow you to manually set the length or angle of an edge/edge pair, the other appears to have several tools but I don't see a manual and the buttons seem ambiguous to me. Perhaps they'd make sense to you, as they're probably based of their CAD equivalent. However, neither of the download pages seem to be working at the moment.....
I've also seen references to a complete CAD toolset/CAD version of Blender, but it looks as though the project died. Sorry.

 

[SolarStorm]

If you want to enter a definite global position instead of typing in a relative manipulation, press n in the 3D view to bring up a little properties window that displays/edits such things.

That's more the sort of thing I was looking for. Thanks.

Once you get used to it, Blender does pretty much whatever you want with little hassle. It's learning curve is steep at first, but flattens out fairly quick. Especially if all you're doing is modeling.

I definitely get the impression that Blender is a powerful program, but the best description I've heard to describe learning it is: "It's like drinking out of a firehose."

 

[T.Neo]

"It's like drinking out of a firehose."

Pretty much. Another way to describe the learning curve is that it's beyond 90 degrees and made of teflon...

 

[simcosmos]

EDIT: I've checked again and I still can't find anywhere where I can input exact geometric dimensions in anim8tor or blender.

SolarStorm, I do not wish to sound in a wrong way but, as in any situation where facing something new, I would recommend spending just a little of extra time reading the available documentation and, in this case, playing a bit more with each software... And yes, this might require a little of extra study effort!

Will next only write about anim8or (only because it is what I use). Do not understand your comment about 'not being able to find where to input exact dimensions': I think that have described what to do on the specific link that posted in my previous text in this thread...

... Maybe I was not clear enough, but again, I would highly recommend some extra study on the available manual / tutorials:

http://www.anim8or.com/manual/index.html
(there is also a version for download at http://www.anim8or.com/main/index.html)

For example:
http://www.anim8or.com/manu/3_object_editor.html#mesh_vs_parameteric

Re-writing what have shared on Usonian's thread (and what is written in the link just above this phrase), in anim8or there are parametric and mesh shapes : parametric can be edited by direct numerical input (to define length, width, diameter, sub-divisions, position, etc) and that is done by double-clicking the basic 3D object (cube, sphere, etc) after creating it...

To further edit such object (for example, manipulate faces, points, etc), it is needed to convert it to 'mesh' first (not Orbiter 'msh', I'm talking about anim8or's 'mesh'): by doing so, the capability of changing length, diameter, etc by direct numerical input is lost but such changes can still be done by using other anim8or features (such as scale changes - both linear and non-linear, being that if it is a linear scale change on all axis it is still possible to use precise numerical input via the 'Edit Menu > Scale' - direct geometry manipulation, etc). Positions can still be edited by numerical input.

For extra tutorials:
http://www.anim8or.com/tutorials/index.html

End like started (and never get tired of writing this): each 3D editor has its own advantages and disadvantages and such do not necessarily means that editor A is better than B or C. What really counts in the end is how comfortable someone feels with a specific editor (for a given objective / goal) and, more than anything, final results only improve with study, study, study and then... practice, practice, practice (and continuous study)

As a final side comment, there is also some generic study that can be made about 3D stuff and that can be applied / adapted to any 3D editor (as long as being aware of the features, constraints, etc of each tool): this is why I usually write that Anim8or isn't the most powerful 3D editor around but, even despite some constraints, it is probably one of the 3D editors with a 'simpler' interface (and, as in any editor, some shortcuts are very handy to memorize) and it can certainly be used to make accurate 3D models of everything... from rockets (which, if we really think about it are not much beyond cylinders and cones transformations) to spacecraft, aircraft and other vehicles, buildings, people, animals, landscapes, etc, etc

But to do exactly what we wish there is really the need to learn the interface and study a little about these topics and that is kind of valid for any 3D editor (and, in particular, if wishing to use the models in a simulator, some extra study about 3D optimization might also be handy not only for things to be smoother inside the simulation - example, allowing more 3D models in a given scenario for a given FPS - but also to reduce things such as zip file size - faster uploads / downloads - or even rendering times / loads - in Orbiter and also with other render tools - although I confess that given the flux of my own (outdated) released and lots of non-released 3D work, optimization is something that I do not try to fully implement yet).

Hope some of this helped,
António

 

[SolarStorm]

Oh great!:dry: Gmax has just decided to stop working. All I get is the splash screen then nothing.

EDIT: Never mind. Just figured it out. And by the way, studying was never my strong point. If I don't intuitively understand what I'm reading, my concentration slips quite rapidly. Modelling for gaming rather than engineering purposes is quite new to me and it feels like a kind of culture shock - the methods and tools for the same tasks are just so different. So thanks everyone for putting up with me. I've got quite a few addon ideas that I desperately want to put into practice (and eventually, the orbit hanger)

 

[Rybec]

I definitely get the impression that Blender is a powerful program, but the best description I've heard to describe learning it is: "It's like drinking out of a firehose."

Only if you go about it the wrong way. It can't be THAT hard, I learned it....
Plus, the same can be said of any professional-grade 3D animation suite. Maya takes just as much effort (only other suite I can directly speak from experience for). Lightwave/3Ds are undoubtedly just as hard.

In the end though, you really just need some good tutorials. Learning straight from the manual never ends well.


And yeah, I can understand the culture shock. I've done it on a slightly larger scale: The engineer's son went to an art school (for 3D animation). The main thing for game modeling is how it looks though, just remember that. Appearance and precision feed into each other though, so if you model accurately it should look nice, and if it looks nice it's likely reasonably accurate. Extreme accuracy can just take up excess time for no noticeable gain other than satisfying your OCD, though.

 

[cinder1992]

I would personally recommend Solidworks. I like it, it's more CAD than 3d-modeling, and blender can import some models that it can export, so I can put them into orbiter.

 

[SolarStorm]

Is there a free version of Solidworks?

 

[cinder1992]

Is there a free version of Solidworks?

whoops, no there isn't.

 

[NuttyPro67]

Is there a free version of Solidworks?

There isn't free solidworks, but there is Google Sketchup:
http://sketchup.google.com/

I had used AutoCAD for the longest time until I found this program, which is perfect for the beginner modeler. Not only that, but it DOES let you input EXACT dimensions in the program. Even better, dimensions are absolute. Another words, in AutoCAD you had "units" which could be cm, in, ft, yds, or any other number of measurements. In Google Sketchup, an inch is always an inch and a cm is always a cm.

The free version CANNOT export 3DS. However, there is a free trial version of Google Sketchup Pro which CAN export 3DS.

The Pro trial version gives you 8 hours of program runtime before it shuts down. So, you download the free AND pro trial. Do your modeling in the free version and export to 3DS with the pro version. Good Luck!