View Full Version : the proper way to aproach a patch model ?

11 November 2009, 01:56 PM
Hi, as i am new here ill just start with a short introduction.
I'm a student residing in Belgrade, Serbia.
Currently i am attending a course in modeling in Maya at the Chiron school for 3d.

at the moment we are working with sub-d's and have already finished nurbs.
but still i still have some pieces to finish and i am very keen on completing them properly.
i am stuck on the planing phase of a nurbs model. we are spoused to make a soda can
and i cant figure out how to approach the top part of the can. i started by doing a revolve of the profile curve and then adding geometry and pushing the cv's into place so i could form the details, however i keep getting a abnormal amount of geometry and an unusable can. i tried detaching the top surface and then trying to start a patch model but again i cant get a effective solution because i cant fit it into the base and attain any kind of continuity with the patches and i dont even want to talk about the amount of 5 patches this has got me stuck with (massive head ache ), i hope i will be able to get a screenshot up soon. but i also hope someone could maybe help me out with how to get around this puzzle.

if anyone has any ideas i would be vary grateful , and a thanks in advance would be in place

so thanks in advanced for the input.

oh and sorry bout the English. not the best, but getting there.

11 November 2009, 05:14 PM
I can tell you, that on nurbs, booleans are actually your friend.
If you're trying to sculpt the top using one big surface and adding CVs that will be difficult.

Try making simple separate surfaces and trimming the pieces you don't need.

I'll try giving more advice once the screenshots are up.

11 November 2009, 06:09 PM
The insets around the hole give you the headaches?
If they do, you can focus on the hole, then build out the cap from there. the thing is, it is very easy to match the cv's to a circle.

those crevisces I would do with with displacement maps, anyway.

11 November 2009, 09:22 PM
right, heres the screenshot, obviously you can tell by this that i went pretty crazy with inserting geometry and didn't really take much care to keep it simple, mainly because this was a test model. however in some places it really was necessary like at the point marked with the blue spiral. i was criticized mainly about this problem, so i was figuring to start from scratch and to try making it out of patches but i am spending a huge amount of time, trying to figure out how a patch model should be planned out because theres to many edges at one given point.
sticking to this solution would be fine if i could figure out a way to decrease the amount of spans, but if i were to go to a patch solution i cant figure out how to even start and finish it without loosing continuity throughout.

also one of the things i forgot to mention is that because this is a nurbs exercise we are not spoused to use trims or any texture tricks for now...

11 November 2009, 05:52 AM
Not allowed to use trims?
Nurbs beg te be trimmed!

Nurbs in Maya are annoying anyway though :p

11 November 2009, 01:24 PM
Well, if the exercise was limited ... "don't use this-or-that" ... do follow that directive. There must have been a reason for it. So what if you are "spending a lot of time." At this point you are learning. The clock isn't running (yet).

You might try with a fresh, new model... keeping your existing file(s) exactly as they are. (Keep every version of everything that you do...) There is such a thing as "too much geometry." And sometimes you do something just to find out how not to do it. :cool: Focusing your attention only on the top of the can, do a "study" of just that part of it. If necessary, turn all of that material in to the instructor for grading and critique.

Your English is doing just fine. Much better than my Serbian... :rolleyes:

11 November 2009, 06:28 PM
The reason being for not using trims is, that basically we will be pushing every model into animation and trims aren't that forgiving with animation. or so we'v been told :)

this file is one of the many versions that i have come up with, and probably one of the most successful by my standards. Again i will try to repeat this one again, and probably stick up a sketch of the plan i started for a patch model, just to get some input. mainly becouse i dont have enough experience with this and i cant repeat another model just to get to the middle and realize somethings gone horribly wrong and have to delete it again.

oh and one more thing, if i had spell check at colleague probably wouldev had better grades

11 November 2009, 06:41 PM
I can see how trims could become unstable once animated.
I guess that's why everything's subdivision surfaces these days.

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