im using Alias 12 to create digital models, what sthe best ways of creating the best surfaces, currently nurbs modelling, and stitching, surfaces however doesnt creat excellent surface continuity. Any tips grateful.
Hi dan, just out of curiosity - why are you stitching geometry together?
Best things to keep in mind for clean surfaces are:
Simple Curves - not too many points in each one... a nice trick is to use edit point curves when possible, and keep them single span (e.g. click start point and end point only, not further points after that).
Surfaces - try and make surfaces from 4 boundary curves where possible. 3 / 2 and so on can be used in many cases, but it depends on how familiar you are with the tools. Use the square tool where poss, as it's pretty powerful. Try not to get too many isoprams on the surafaces (the green lines inside the surfaces). The more there are, ther more complicated and ultimately messy the surfaces can become + it can easily become harder to build further clean surfaces off messy ones.
Use things like 'align' tool to snap curves together... open up it's options box and select the desired continuity (tangent / curvature etc)... that way when you snap one curve to another it will flow off it at the desired level.
Just remember, if your curves dont flow through each other correctly, any surfaces you build most likely wont.
Don't know if that helps ya, I've kept the descriptions pretty simple cus I'm not sure of your level - post your folio and I'll get back to ya with more useful feedback.
Don't know if that helps ya, I've kept the descriptions pretty simple cus I'm not sure of your level - post your folio and I'll get back to ya with more useful feedback.
Nanna
Hello Nanna
Can u explain some methods to do a model that almost reaches the quality of an A class surface? Some tricks... I work with alias, and i do my tasks using the methods that u said and others... But i dont know how Alias can do an A class model.
Did somebody of all you heard for solid – parametric modelling? Only suggestion to think about. I am aware of Studio Tools and its possibilities (I use them – now V 13), but I think there is something better. Something like ProE or Catia – even Ideas (master series) if still available on the market.
To make class A the advice of Nanna Moon regarding surfaces is good and try to keep the isoprams to a maximum of 9x9 (normal for class A). Normally you don't built two surface based on the two same curves but try to have the desired intersection curve when the two surfaces intersect. However to make good intersections is the complicated stuff. The curves of the surfaces must have the same amount of points and the distribution must be the same (more or less); the more they will have so the better the surfaces (without dents...) Class A is a defintion of how surfaces connect (curvature, tangent, etc.) and that is different for all car manufacturers; Audi has the highest requirements (what I have seen untill now), then Mercedes, Porsche and Ford/Opel. My advice is keep the surfaces simple...class A surfaces can be made with Alias but it is more tricky then ICEM and untill now the only who do it is GM (Saab, Opel)
Here i have a square surface (the green one), and it has Curvature connection with another one, and position connection with another, and the others sides are connected to curves. My doubt is: I can build this surface using 4x3 degrees. Is it better to use 5x5 degrees for all surfaces (ie) or the minimum necessary for a perfect matching??
Another doubt: Is it better to have a curvature or tangency connection using colinear option? Colinear
One more question, are the tolerances right?
Thanks!
This message has been edited. Last edited by: m-class,
The tolerances are too high (altough I don't know what reference they have); the closer to 0 the better (in the ideal world connections should be 0) but 0.5 is too high. Maybe somebody who works with Alias and Class-A experience can help here? Try 0.005 and see what happens. Sometimes a 4x3 can work but check the tolerances because maybe you need a 5x5. If two surface intersect then it doesn't matter if one is 4x3 and the other 5x5. If the connect to another then the same iosprams is better. Curvature is beter but that can change the surface a lot; if that is o.k. you can do it. Sometimes it won't work so then tangent is better but try to have curvature connections. Have fun!
In class-A surfacing what counts more than everything and regardless of what tools and software you want to use is experience and technical knowledge of surfacing. In particular when you work with StudioTools. You have to know what you are going to do and can foresee what could be the results. STs are feature-rich surface modelers but you have to be aware of performance issues and to avoid unnecessary nodes in your scene and if you can afford keep your Maya handy! Fortunately the scenarios for technical surfacing are not infinite and when you learn how to approach any of them and have developed your discipline it is not a big problem to work with any of those high-end surface modelers. For me Imageware is a much faster and robust tool for most of surface modeling and evaluating tasks even though I don't rely on it as the only surface modeling tool. I like the combination of NX and Imageware but I like Catia and ProENGINEER too, as well. I hope someone in Autodesk hear this: Put the ST’s features and tools into Maya and say "No, thanks" to Studio’s interface, rename it if you like and then try to learn some small tricks from Rhino, Delcam's PowerShape and Solidworks, and then sell it!
