Discussion AutoCAD, anyone?

[Usonian]

All of my addons meshes are created with AutoCAD, which is NOT an ideal tool for doing this work, but it's what I know. (I'm an architect and have used AutoCAD for 15 years). I export the .dwg model to .3ds, then convert to .msh using both 3ds2msh and MeshMaker which is where the real hair-pulling "fun" begins...

MeshMaker produces smooth, unfaceted surfaces with a low polygon count, but the faces are one-sided and AutoCAD doesn't not provide complete control the "normal" direction for mesh faces, so the finished Orbiter model is sometimes "inside out." I know that meshmaker is supposed to have a "2-sided" feature but I don't find it realiable -- MeshMaker has many little hiccups that must be worked around.

3ds2msh is more reliable and predictable (I have worked up batch files to deal with its DOS interface -- boy, am I old). The "normal" direction is not an issue becuase 3ds2msh ALWAYS produces 2-sided mesh faces, but at the cost of an inflated polygon count. The biggest drawback is that 3ds2msh does no smoothing -- curved surfaces are faceted by 3ds2msh and unacceptable looking.

Am I the only one creating Orbiter addon models this way? If there is anyone else out there struggling along in similar fashion, I would like to discuss and trade information. I have tried Anim8tor, but the leap from AutoCAD is too big -- I'm not interested in learning how to draw all over again. Can anyone out there suggest a 3D program (freeware preferred) that is more similar to AutoCAD? Are there better choices for converting 3ds to msh? Perhaps import my AuotCAD generated 3ds file, flip normals as needed, then export again to 3ds.

I want to do a version 3 of Skylab, with full interiors, but I think I need better production methods.

 

[BrianJ]

Hey there,
I use Anim8or(nice simple interface) to generate a .3ds model. From there, I import it into Gmax for texturing, smoothing, tweaking, etc. And export as .msh using Mindblast's "Max2msh" script. The nice thing about Max2msh is
a) smoothing and scale is preserved
b) no nasty "seams" along texture edges.
c) easy to import .msh for further tweaking, etc.

Of course, you'd need to get Gmax(free) or 3DSMax($'s) installed, which is maybe more hassle than you want.

All the best,
Brian

 

[francisdrake]

I did my first model also in AutoCad, but was frustrated that it did not support mesh smoothing and many other features required for a good model (including full control of vertices and faces).

After trying several free modeling programs I ended up with Gmax. I am still happy with it, although its development is discontinued now. It has all the features from primitives to really complex mesh manipulation, can do all texturing and has a good mesh exporting-script (max2msh).

 

[Donamy]

AC3D is only $90 US and is the easiest to to learn IMHO. Also has a very good plugin for input and output to Orbiter.

 

[Usonian]

Thanks for the replies! There were some threads from a couple of years back (and maybe further, on the old forum) that hit the same points and programs -- nothing new, it seems.

Being a stubborn luddite, I will probably continue with AutoCAD. It's true that I spent many cumulative hours teaching myself various tricks and work-arounds, and if I had devoted that time teaching myself Anim8tor or Gmax I would probably be ahead of the game. But that's only clear in hindsight. The Orbiter addon addiction creeps up on one slowly -- you start out with something simple, using what you know, then the complexity builds and after some months you are so far down your path it's hard to imagine starting over.

I think my biggest problem with Anim8tor is that it seems to be more "artistic" than "technical" -- in AutoCAD you type in exact dimensions, that's just how it's done. I never figured out how to do that in Anim8tor. I abhor "eyeballing" a model and it's wonderfully satisfiying to have it fit perfectly into the Shuttle cargo bay, or on top of a Delta, Titan or Saturn, without scaling or manipulating.

I will give Gmax a look, since it's free. Being "cheap" is an important feature of being a luddite.

 

[Loru]

Having a lot of experience in one particular modelling software makes transitions very difficult. For modelling I'm still using old dos 3D Studio while 3DS Max serves me only as texturing and rendering tool
.

 

[jedidia]

so the finished Orbiter model is sometimes "inside out."

If that's the only problem, MeshWizard has an option for inverting and correcting normals, which in my expierience works quite good. There are sometimes even problems with normals when exporting from 3ds Max, and MeshWizard always fixed them pretty much itself.

 

[Usonian]

If that's the only problem, MeshWizard has an option for inverting and correcting normals, which in my expierience works quite good. There are sometimes even problems with normals when exporting from 3ds Max, and MeshWizard always fixed them pretty much itself.

I haven't played with MeshWizard. Does it invert the whole mesh, or can you select individual polygons?

 

[markl316]

I'm a student and use Autodesk Inventor. Is there a way to export .ipt or .iam files as .3ds? Then I could actually make some meshes :thumbup:

 

[simcosmos]

( . . . )

I think my biggest problem with Anim8tor is that it seems to be more "artistic" than "technical" -- in AutoCAD you type in exact dimensions, that's just how it's done. I never figured out how to do that in Anim8tor. I abhor "eyeballing" a model and it's wonderfully satisfiying to have it fit perfectly into the Shuttle cargo bay, or on top of a Delta, Titan or Saturn, without scaling or manipulating.

I will give Gmax a look, since it's free. Being "cheap" is an important feature of being a luddite.

Hi Usonian


Although, when comparing with other 3D editors (such as gmax, blender, etc), Anim8or might not allow the control or simplification of some procedures or even offer some advanced features, I'm not sure if understand your specific comment about dimensions.


Imagine you wish to create a rocket stage or a station module, etc with a given diameter: it is only a matter of clicking on the cylinder primitive (or use the Build menu), drag the mouse (left click) to create a very generic cylinder with the indented orientation and, when done, then double-click on such cylinder to further edit stuff such as number of latitude/longitudinal divisions, top / bottom diameters, length, location... Rotations, Scales, etc can also be edited later.



Same is valid for other forms (cubes, spheres, etc). The Build - Primitives top menu also offers a few additional configuration options (beyond what is available on the left visual menu).


Anim8or also allows for using / sizing reference images on the background (Menu Build – Reference Image). The background grid can also be tweaked (Menu Options – Grid: I prefer to used 'fixed grid' and, depending of project, adjust the minimal size of the square = 'Objects'). By the way, you can think that 1 unit in Anim8or = 1m.


Then there are a few extra tricks regarding texture work, shaping 3D parts...



I like Anim8or because despite the lack of some advanced features it is still very flexible and quite amazing for a file size of just a few MB (the version I'm using is less than 2MB) which does not require installation to run!



Then, to export, is just a matter of converting to 3ds and, if the 3D model was properly aligned in Anim8or, it is a matter of running Vinka's 3ds2msh with a given set of parameters (I prefer to run it from the command line or else make/edit a .bat file in order to have better control of some extra options, please see Vinka's readme). EDIT: I also edit the .msh later only to modify the path of the textures to a custom directory structure and to add a few extra 'visual effects' on materials properties; for texture bmp-to-dds I use the DXTBmp software)




This all to say, that in the very end, it does not matter much which tool is used for which step: what matters is how comfortable each user is with each tool and also how knowledgeable the user is about the tool's eventual limitations and about how to workaround them (for example, in the past I provided an interesting tip to GregBurch that allowed him to significantly improve the quality of the conversion procedure of his cool spaceplanes / work). In the same way, there are a few other tips and tricks Beyond that, with time and enough practice on a given tool, the quality of the models tends to naturally increase.


Only for reference and although I do not consider myself a '3D guru', all the 3D stuff that is displayed on my flickr space to date and/or on my LivePics, etc has been made with Anim8or...


Happy development,
António

---------- Post added at 02:33 PM ---------- Previous post was at 12:35 PM ----------

Hey there,
I use Anim8or(nice simple interface) to generate a .3ds model. From there, I import it into Gmax for texturing, smoothing, tweaking, etc. And export as .msh using Mindblast's "Max2msh" script. The nice thing about Max2msh is
a) smoothing and scale is preserved
b) no nasty "seams" along texture edges.
c) easy to import .msh for further tweaking, etc.

Of course, you'd need to get Gmax(free) or 3DSMax($'s) installed, which is maybe more hassle than you want.

All the best,
Brian

Hi Brian

Not sure if understanding your post but, as far as I'm aware, scale can be preserved when exporting from Anim8or to 3ds and from 3ds - via 3ds2msh - to msh.

In what concerns the smoothing and "nasty "seams" along texture edges" it is possible to either:

a) build / texture the 3D models in Anim8or in a way that avoids such issue when exporting the .an8 model

b) and/or to fix the issue on the .3ds model itself by using another program to quickly 'resave' the .3ds (such as older versions of 3D Exploration; ProgMesh might also be useful as a complement to Anim8or)...

But again, depending of the objectives and a few additional considerations, it is perfectly possible to make a 3D model in Anim8or which, when exported, is clean (without smoothing issues or "nasty seams").

António

 

[jedidia]

I haven't played with MeshWizard. Does it invert the whole mesh, or can you select individual polygons?

I'm not sure, only the whole mesh I think. There's also the correct normals option, which I used to fix the inverse lighting problems that show up some times, which worked in about 90% of all cases. Maybe it also flips normals it thinks are looking the wrong way too, but I wouldn't bet on it.

 

[simcosmos]

Usonian, please allow me an extra comment about this part (by the way, if I'm writing nonsense please someone feel free to correct / complete as needed!):

3ds2msh is more reliable and predictable (I have worked up batch files to deal with its DOS interface -- boy, am I old). The "normal" direction is not an issue becuase 3ds2msh ALWAYS produces 2-sided mesh faces, but at the cost of an inflated polygon count.

As far as I'm aware, 3ds2msh does *not* produce 2-sided mesh faces (unless we are using the same expression to mean different things), EDIT: I mean, it does not work on normals / faces if they are not there in the first place.


Example: imagine that a simple cube is made in Anim8or and then one face is deleted.

When exporting to .3ds the five remaining faces of the cube will be transformed into 10 triangles (each squared face will be divided in two triangles, this can be seen by importing back the 'cube.3ds' into Anim8or; EDIT: people making models might have better results if thinking in triangles as the basic 'face unit'... this might help some modeling steps, in particular in slightly more complex shapes / parts and avoid a few surprises before exporting to 3ds...) but the interior of that cube will not gain any internal faces / internal normals neither when exporting to .3ds from Anim8or neither when using 3ds2msh to convert to msh...

… This means that, when looking at such 'cube.msh' inside Orbiter simulator, all (5) faces (except for the deleted sixth face) will be visible from the exterior (normals pointing outwards), and also means that, if rotating the view to try to look at the interior of the cube (via the missing face 'hole'), no internal rendering will be made (no faces / normals pointing to the inside of the cube were added by default by 3ds2msh).

Note: if wishing to have internal render of the cube, one simple solution could be to create a copy of the model in Anim8or and then reverse the faces in the 3D editor (this way the internal walls of the cube would be created, with normals pointing to the interior).


The .msh files that exit from 3ds2msh may result in bigger file sizes than the original .3ds file but that seems to be caused by some other specific reasons which are also related with normals calculations for the existing faces, etc (would need to see development notes) but again, *not* related with the addition of completely new internal faces / internal normals by 3ds2msh (EDIT: other than stuff related with the internal faces / internal normals already existing in the original 3D model, by option of the 3D author, argh, not sure if I'm making myself clear)

EDIT: it wouldn't make much sense for 3ds2msh to add 100% new internal faces / normals or, in more generic terms, add a 'second side' to every face (in fact, only as example, the author of a 3D model might not want internal rendering of some components, which are hidden and have no purpose in being rendered... interior of crewed spacecraft or any other specific case are other completely different things and, in such cases, it is the 3D author job to make sure that such internal faces / normals are created in the first place, within the 3D editor itself and not as part of the conversion procedure... EDIT: such internal rendering might or not have full or partial external rendering, depending of strategy for the building of the internal layout and its integration with eventual other components).

I'm writing this from the top of my head: if someone wishes extra considerations about the topic (in particular related with using 3ds2msh) I would have to do a better look at some of my past development notes (for example, related with some 3ds2msh parameters vs final file size variations, from an older post that wrote back on M6 forums, need to check) and also would need to have a look at Vinka's 3ds2msh readme (which does not seem to be included on the 050630 version currently online - EDIT: not sure if such readme was included on older versions or if more detailed info was given by Vinka on older M6 posts, would have to check on a later occasion - in any case, instructions are provided in the 3ds2msh executable if running it, from the command line, without parameters)...

If that happens (wish for extra development talk related with 3ds2msh) it might be better for someone to please open a new thread (with a new specific tittle) on this Development Section of Orbiter Forum.

António

PS: Urwumpe also seems to have developed an integrated exporter plugin for Anim8or (although can't talk about the constraints / details of such tool because never used it)

 

[BrianJ]

Hi Brian

Not sure if understanding your post but, as far as I'm aware, scale can be preserved when exporting from Anim8or to 3ds and from 3ds - via 3ds2msh - to msh.

In what concerns the smoothing and "nasty "seams" along texture edges" it is possible to either:

a) build / texture the 3D models in Anim8or in a way that avoids such issue when exporting the .an8 model

b) and/or to fix the issue on the .3ds model itself by using another program to quickly 'resave' the .3ds (such as older versions of 3D Exploration; ProgMesh might also be useful as a complement to Anim8or)...

But again, depending of the objectives and a few additional considerations, it is perfectly possible to make a 3D model in Anim8or which, when exported, is clean (without smoothing issues or "nasty seams").

António

Hi Antonio,
don't get me wrong - I think Anim8or is excellent software, and as you say, it is quite easy to create models "by the numbers" (Usonian's preferred method). However, Gmax does have more sophisticated texturing facilities (and some other useful functions) and I find the work flow of
Anim8or -> .3ds -> Gmax -> .msh
very simple to use.

But it's just personal preference - your models always look great, so stick with whatever works for you

Best regards,
Brian

 

[Usonian]

Simcosmos,
I may be missing some feature of 3ds2msh, but when I use it it always creates "two-sided" faces, by which I mean 3ds2msh "doubles" each triangle and points the normal of each pair in opposite directions.

So, create a cube in AutoCAD, with one side removed, and export it to Cube.3ds. Open up this .3ds with a viewer (such as 3D Exploration) and we see what you have described: the exterior side of all five faces of the cube are visible, the interior sides are not (as we can see through the cube's open side).

Run Cube.3ds though MeshMaker to create Cube.msh. This finished Orbiter mesh looks the same as the .3ds file in the viewer -- visible exterior faces, invisible interior, and Mesh Wizard says the mesh has 10 triangles. Now run that same Cube.3ds through 3ds2msh. The faces of this second Orbiter mesh will be visible inside and out, and Mesh Wizard says there are 20 triangles. With perfect consistancy, I find that meshes created by 3ds2msh have exactly twice as many triangles as meshes created from the same 3ds file using MeshMaker.

This can be handy if you want to see both the inside and outside of the cube, or if (as in AutoCAD) your 3d drafting software doesn't permit you to override the default direction it assigns to the normals.

I assume the same things will happen if you export Cube.3ds from Anim8tor -- after all, both programs are generating .3ds files.

Does everyone see these two mesh generators acting as I've described? Is there a command line option I don't know about that forces 3ds2msh to create one-sided faces?

Thanks to jedidia for the Mesh Wizard tip -- it's going to be very helpful. It doesn't appear that it will "flip" the normals of individual triangles, but it will flip all the trinagles in a mesh group, which is generally what I need to do.

I have yet to try Gmax, but that's near the top of my to-do list.

 

[simcosmos]

[FONT=Arial, sans-serif]Anim8or, 3D Models Conversion, Mesh Smoothing[/FONT]

[FONT=Arial, sans-serif]

Hi Antonio,
don't get me wrong - I think Anim8or is excellent software, and as you say, it is quite easy to create models "by the numbers" (Usonian's preferred method). However, Gmax does have more sophisticated texturing facilities (and some other useful functions) and I find the work flow of
Anim8or -> .3ds -> Gmax -> .msh
very simple to use.

But it's just personal preference - your models always look great, so stick with whatever works for you

Best regards,
Brian

[/FONT]

[FONT=Arial, sans-serif]Hi Brian, [/FONT]
[FONT=Arial, sans-serif](thanks for the kind words, by the way, I enjoy very much your work)[/FONT]
[FONT=Arial, sans-serif]
I completely agree with what you wrote, please note that I was only trying to provide a little of extra information to let eventually interested Anim8or users know that, within and despite some constraints, it is possible to use that 3D editor to produce somehow complex models which, when converted, do not display those ugly seams. [/FONT]

[FONT=Arial, sans-serif]
Only for a little more of completeness, the 'constraints' mentioned on the above paragraph are related with things such as the way the 3D model is built in Anim8or in the first place (in particular, some curved shapes and also the way holes are opened) and then there are also a few additional tips and tricks, for example... [/FONT]

… [FONT=Arial, sans-serif]It might sometimes be worth to apply, at least, a 'dummy' small texture to some more complex (rounded) parts of the model (even if such part is not intended to really be textured): I have found out that this trick (together with other strategies) is able to solve most (not all) of the smoothing related issues that might otherwise appear - depending of the 3D model - on the .an8 to .3ds to .msh conversion procedure (it also depends of exact texturing objectives / method). [/FONT]

[FONT=Arial, sans-serif]I wrote about this (and other related topics) on the older M6 forums but, as we all know it, those kind of precious forum resources seem to be mostly offline (and the related google cache and/or waybackmachine also do not seem to return cached versions)... [/FONT]

[FONT=Arial, sans-serif]... In any case, made a quick hunt on my 'simcosmos development archives' for copies of that specific post (found the post saved in pdf format): for a better organization of the information will soon attach such pdf in another thread of these Orbiter Forums, the interested in reading the pdf might wish to please visit the following link to download the attachment (will edit the current post when the attachment is uploaded):[/FONT]

[FONT=Arial, sans-serif]http://orbiter-forum.com/showthread.php?t=807[/FONT]
[FONT=Arial, sans-serif]( Animator Mesh Smoothing )
( http://orbiter-forum.com/showpost.php?p=194423&postcount=14 )
[/FONT] EDIT: pdf now attached at the above post link


[FONT=Arial, sans-serif]3ds2msh vs Normals Creations (vs Internal / External Normals) [/FONT]

[FONT=Arial, sans-serif]Hi Unosian[/FONT]

[FONT=Arial, sans-serif]Yes, it seems that we are talking about the same thing but I do not confirm that 3ds2msh creates double-sided faces (at least not by default). I did what exactly have written on my last post, which also seems to be what you have written too (creation of a cube inside the 3D editor - Anim8or on my case - removal of one face) then converted to cube.3ds (which creates a cube where each square is composed by two triangles, 10 faces on total) then used 3ds2msh (without any extra parameter beyond what had written on one of my generic .bat files: a=-xyz, f=v) to convert such cube.3ds into cube.msh and, inside Orbiter, it shows as in 3D Exploration (all cube faces - except the deleted one - visible on the exterior and no internal rendering if trying to use the 'hole' of the open side to look at the interior). [/FONT]


[FONT=Arial, sans-serif]Not sure what is the cause of the apparently different behaviour of 3ds2msh (from what understood, it seems that you are getting creation of double-sided faces with a default use of 3ds2msh and no other extra tool?): to further study the question we would probably need to spend a little of extra time, for example, to make sure that we would be using the same software versions and/or the same .3ds source files, etc. [/FONT]


[FONT=Arial, sans-serif]I would also like to try to find / review some of my older development notes about related topics (in particular, somehow side-related, I wrote yet another old post at M6 forums about some things related with final file size variations of 3ds2msh outputs vs quality vs normals calculation related parameters, etc). [/FONT]


[FONT=Arial, sans-serif]But again, from my side I can't confirm that 3ds2msh creates double-sided faces (I mean, if those faces aren't already there in the original 3ds). [/FONT]

[FONT=Arial, sans-serif]Unosian, if wishing to further study the topic it might perhaps be better to open a separated thread, with a specific title (and / or private messaging / email could also be an option, if wishing to better share some development notes / files without cluttering too much the forums with some verification middle-steps) [/FONT].

[FONT=Arial, sans-serif]António [/FONT]

 

[Usonian]

[FONT=Arial, sans-serif]Not sure what is the cause of the apparently different behaviour of 3ds2msh ...[/FONT]

[FONT=Arial, sans-serif]António [/FONT]

Very interesting. The only apparent difference in our methods is the starting point -- Anim8tor vs. AutoCAD. I guess AutoCAD is doing something to the exported 3ds that effects 3ds2msh but not MeshMaker.

 

[simcosmos]

Very interesting. The only apparent difference in our methods is the starting point -- Anim8tor vs. AutoCAD. I guess AutoCAD is doing something to the exported 3ds that effects 3ds2msh but not MeshMaker.

If wishing to clear first some doubts about if, for example, the difference is or not in AutoCAD output interaction with 3ds2msh, please feel free to email me a 'cube_Usonian.3ds' (as produced from AutoCAD) and, when possible, I will try to have a look at it (would compare it with a 'cube_simcosmos.3ds' (as produced by Anim8or) and then convert both with the same 3ds2msh, etc)

António

 

[Usonian]

Thanks for the offer, Antonio. I have sent the files to your.

I sent the CubeUsoninan file to the email address on your web page -- I hope that account accepts attachments. If not, send me a private message with the email address to use.

In any case, I have been working around my 3d drafting problems for years. But now I am running up against a serious snag in my development of a Skylab interior that will need a new thread...