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View Full Version : Some questions about Maya NURBS Modeling(Without trim).


XaMiC
08-19-2005, 10:29 AM
Hard surface models typically represent man made objects like cars,airplanes, ships, robots, and so on. These types of objects often have very complex topology, and require trimming. However, trims add to the complexity of the model, and place many requirements on the model, which further increase its complexity. A trimmed edge will often need a "round"surface to avoid the sharp edge. Trims basically make a part of the surface that is discarded - invisible. Since the invisible part of the geometry is still there, any texture applied to the model will only be partially visible. Also,trimmed edge doesn't have the same characteristics as an edge of the bspline edge, and we will not be able to manipulate it in the same way - with attach, or to make it easily continuous with another surface.

It is possible to create hard surface models without using trims, but it can be a challenge sometimes, depending on the model. This type of model always requires more modeling time, but also saves a lot of time in other steps of production. One other advantage of non-trimmed models is that if needed they are easily converted to polygonal models.Trim edges tend to produce a high poly count.

I'm very instersted in patch modeling,it is so beautiful to me.There are no problems to do organic modeling with patches for me.But hard surface models seem to be not so easy. Some kind of surfaces even I looked into their wireframes still made me confused. How these guys build their model?

I got some jpgs posted here. The "incrediable surface"will be marked out. Hope you guys can help me.
:eek: Only 3 files to the limited....

XaMiC
08-19-2005, 10:35 AM
Ok.All the pics are posted....

JasonA
08-21-2005, 04:52 PM
Its pretty tough to get all of your nurbs curves laid out perfectly on the first modeling pass. In order to model all those 'tricky' areas you mentioned in your pics is that you usually have to create the surface twice.

The first time around, you create your surface using trim tools to get the overall shape down. Then you use the trimmed surfaces along with the offset curve tools to generate new splines so that those trimmed areas can be rebuilt as 4 sided patches instead of trims. What you're left with is a non-trimmed model. I used this very technique on a trek model I made recently. If you look closely at most of those surfaces in your pics you can see that this paridgm is used as well.

The only thing that sucks is that texturing all these nurbs patches is a pain in the ass, unless you use 3d projections which is limiting in how you can use them.

:thumbsup:

XaMiC
08-22-2005, 04:37 AM
Its pretty tough to get all of your nurbs curves laid out perfectly on the first modeling pass. In order to model all those 'tricky' areas you mentioned in your pics is that you usually have to create the surface twice.

The first time around, you create your surface using trim tools to get the overall shape down. Then you use the trimmed surfaces along with the offset curve tools to generate new splines so that those trimmed areas can be rebuilt as 4 sided patches instead of trims. What you're left with is a non-trimmed model. I used this very technique on a trek model I made recently. If you look closely at most of those surfaces in your pics you can see that this paridgm is used as well.

The only thing that sucks is that texturing all these nurbs patches is a pain in the ass, unless you use 3d projections which is limiting in how you can use them.

:thumbsup:

Thank you very much!:thumbsup:
Unfortunately there's no wiresframe of your newly made Star Trek model.....So nice a model.
The method build twice you mentioned seems a new world to me.Thanks again.
Practising!:bounce:

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