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3D modelling tips

Posted: 2006-02-20 01:11pm
by Jawawithagun
I'm looking for some helpful comments on this.
I just started to teach myself a bit of 3D modelling, and with what else as a first project? A spaceship of course. The attached pic is my first attempt at trying to build the drive section and it just doesn't look right to me, without being able to place what makes it feel wrong.
So, does anyone have any ideas, hints?
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Posted: 2006-02-20 07:57pm
by Simmon
First of all, what type of ship are you making?
More importantly, what software are you using?

Posted: 2006-02-20 08:40pm
by lPeregrine
It would help if you could post a sketch of the ship you're trying to make, and some detail on what software you're using and have available. Right now, it looks fine for a first model. A bit low and simple in details, but that's expected... it would look decent with textures and a real lighting setup.

Posted: 2006-02-21 09:53am
by Kenny_10_Bellys
If it's meant to be a rocket engine of some sort your best bet is to do some research on real rocket engines and use what you see as the basis for your design. Always check out as much design as you can before beginning your own design so that you know what to go for and what to avoid. Right now rather than 3 or 4 large spherical tanks at the neck of the rocket engine you have dozens of small ones around the bell of the rocket and it just looks like a necklace rather than tankage.

That's maybe part of the problem, you have a highly decorated outer engine and the inner bell has no detail whatever. Go look at engines on Star Wars stuff, lots of detail inside the engine nozzles as well as outside, which makes for a more interesting view when seen from behind and also hints at a technology a little more advanced that rocketry.

Posted: 2006-02-21 12:53pm
by Jawawithagun
Thank you, Kenny. I can see your point.

I'm working in Cinema4D.

I'm trying for a retro-fitted look between the ship's bodies and installations, engines etc. and the hulls as (in-universe explanation) their human builders were using prefabricated alien bodies and slapping their own modifications onto them.
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Possible hulls I'm planning to use:
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And a fighter
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All these models were created with sPatch and as may be obvious on some of the pictures the exported meshes are a mess.

Posted: 2006-02-21 03:23pm
by Alan Bolte
Jawawithagun wrote: Fighter
It's the Vengeance!

Posted: 2006-02-21 05:23pm
by lPeregrine
How are you making the hulls? Poly modeling + meshsmooth or splinecage + surface? Right now you've got some really bad mesh errors. I'd have to look at your wireframes and modeling method to tell you how to fix it though, I'm not sure if it's because of a random misaligned vertex or two, or because of too few segments in your curves. But you shouldn't have those creases in the surface, it's a sign that something isn't working right.

If the plugin is making such a mess of things, why use it? I've never used C4D myself, but from what I see/hear it has all the tools you need. It would probably be easier to just do all you modeling there, and not worry about import issues.

Posted: 2006-02-21 05:53pm
by Kenny_10_Bellys
I just want to echo what Peregrine says, check out how your making those meshes and find a way to correct the problems and lose the creases. No point basing your funky new human hybrid designs on bodies that are flawed from day 1. Increase the detail level so that there's enough to make the curves look smooth, or find what's pulling the curves out of shape before you go slapping on detailed engines and so forth.

I'd also be wary of using some of those shapes for making ships unless they're way bigger than we think. Unless they're seriously huge they'll just look very odd when you strart trying to stick stuff on some of them and make it fit.

Posted: 2006-02-21 06:59pm
by Jawawithagun
The hulls are made by building a spline outline in sPatch and then exporting as a dxf (that and VRML are the only file formats the two programs have in common).
So I'll probably just have to find out how to redo them and better in C4D. :)

Posted: 2006-02-21 07:19pm
by lPeregrine
Hm, if all you're importing is the outlines, it might be salvageable. It's probably a case of misaligned points or too low detail. When you're building the surface, can you increase the curve segments? That might make it flow better.

Posted: 2006-02-21 07:21pm
by Darth Paul
You may want to try the vrml option if you haven't already. I have heard of others having more success than with dxf. If you can get your mesh to wavefront obj format, C4D is strong with that format... For sure you could also do those shapes in Cinema.

Are you putting that mesh in a hypernurbs in C4D? It looks like maybe you need to connect/weld the different patch components first, although it could just be hopeless due to the dxf import problems...

I would recommend http://www.c4dcafe.com as a really good C4D resource. There are some great video tutorials and a friendly user forum to get you going there.

Posted: 2006-02-21 08:52pm
by Jawawithagun
The vrml option gives, as far as I can see exactly the same results as the dxf, except when putting it in a hypernurbs (then the result is holes in the nurbs where in sPatch were the anchor points for the skeleton splines).

One problem with the meshes seems that they have lots of polygons interpenetrating, which seems to be one major fault in the original modeller.

Posted: 2006-02-21 10:51pm
by lPeregrine
Can you post wireframs and screenshots of the spline cage un-surfaced for each hull design? That might help with figuring out where your problems are coming from.

Posted: 2006-02-22 12:25am
by Jawawithagun
The images are a bit bigger this time, so no inlining. And the wireframe shot have to wait until tomorrow.
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Posted: 2006-02-22 04:22pm
by lPeregrine
Hm, you'll have to ask someone else for problems with the spline cages themselves, I don't really do that kind of modeling. When you're adding the surface, is there an option for how many segments/polygons to use? Try setting it to a really high number, at least 10-20x what you have now. If that fixes it, your splines themselves are fine, but if you still have creases and errors, try adding more splines to define the shape better.

Posted: 2006-02-22 05:27pm
by Jawawithagun
As I just can't get any good wireframe views of the meshes, I just uploaded the DXFs here on Rapidshare.

In the original modeller there's no option to do this. When exporting them on medium and high settings (32 and 89 polygons per patch respectively) the results are nearly identical.

Posted: 2006-02-22 06:18pm
by lPeregrine
Two problems:

1) Could you post the original spline forms, un-surfaced? I'll try it in 3dsmax and see if I can find the problem.

2) Don't use .dxf for your import. It's doing some nasty things to them (half the faces deleted in one), and it can't handle NURBS models. It has to reduce everything to polys, and does a bad job of it.

Posted: 2006-02-22 08:49pm
by Jawawithagun
lPeregrine wrote:Two problems:

1) Could you post the original spline forms, un-surfaced? I'll try it in 3dsmax and see if I can find the problem.

2) Don't use .dxf for your import. It's doing some nasty things to them (half the faces deleted in one), and it can't handle NURBS models. It has to reduce everything to polys, and does a bad job of it.
Here you go

I'm currently trying to rebuild the models natively in Cinema.

Posted: 2006-02-22 09:09pm
by lPeregrine
File format doesn't work. What I mean is give me the files in .dxf format, but export it before you put the surface on. I just want the splines in .dxf format so I can surface it myself.

Posted: 2006-02-22 10:16pm
by Jawawithagun
it's the sPatch native format. The program is avalable freely, linked a few posts up.

There's a misunderstanding here. I do not not put a surface on anything. All I have to do in the program is build a skeleton of connected loops that the program automatically translates into spline patches. There is no extra process for skinning involved.

On the gripping hand, I've redone one of the hulls in C4D. The result.

Posted: 2006-02-22 11:02pm
by lPeregrine
The C4D version looks a lot better, so I suspect the problem was in your old software, not your construction methods. I'm not sure how easy it's going to be to add details to it, but at least it doesn't seem to have mesh errors anymore.
There's a misunderstanding here. I do not not put a surface on anything. All I have to do in the program is build a skeleton of connected loops that the program automatically translates into spline patches. There is no extra process for skinning involved.
Actually you do, whether the program calls it a formal step or not. And that might be part of the problem, if it's just skipping over any chance to adjust the skinning.

Posted: 2006-02-22 11:17pm
by Jawawithagun
I'm very happy with the new result. Especially as it was the first time I used this Cube-inside-HyperNURBS method for modelling.

Posted: 2006-02-25 09:37am
by salm
What the hell is the Cube-Inside-HyperNURBS method?

I know that HyperNURBS are the C4D uquivalent to MeshSmooth, but what what´s the rest?

Posted: 2006-02-25 10:21am
by Jawawithagun
salm wrote:What the hell is the Cube-Inside-HyperNURBS method?

I know that HyperNURBS are the C4D uquivalent to MeshSmooth, but what what´s the rest?
Take a cube, make it editable (i.e. turn it into polygons) and resize it to roughly the size you need the result to be, then put it into a HyperNURBS.
Then you use the knife tool to cut the polygons where you need to reshape and work out details.