View Full Version : Detailing mechanical surfaces with curvature

02 February 2005, 10:32 PM
I am creating a helicopter. I have come to the part where I need to start modelling in details around the body. I start with this simple base mesh, and it is smoothed with either subdivisional surface or a poly smooth. Problem is, as in this example, I want to add some kind of opening to the surface. It completely messes up the curvature of the surface by having the curvature protrude out to where the detail was added. I try to adjust the cvs back or something, but no go, it still looks awful.

Advice/tips on how to go about this is much appreciated. Last time I made a smooth mechanical object it was in NURBS and much easier to work with, just project a or intersect with a cylinder, fillet, done. No mess like this. (
Click for high-res version

1. This is my base mesh
2. Add a gas tank hole
3. Tweak,
4. Smoothed, looks like crap!
5. See how curvature rises to meet where detail is higher. I know this is expected behaviour, I am trying to figure out how to compensate.
6. Pushing vertices back still doesn't help as seen by result in
7. Still no good

I work in Maya. Advice/suggestions? What works for you? I have a lot of little holes and stuff like this to add now. I know I could make those lines that stick out smaller by making the mesh a littler denser around there or something, but this is for example sake. At any level, this is a problem. On the real helicopter, it is like a hole was cut in an already nicely smooth surface. No lips, no weird lines or plateaus or difference of curvature. Smooth as a babies bottom.

02 February 2005, 11:52 PM

Try to make some extra cuts. that way you can make a "boolean" without screwing all of your mesh, but only inside the cuts..

I hope you understand.. My english is very poor.

Best regards, Jakob

02 February 2005, 12:06 AM
I understand perfectly. Thank you. :)
It was suggested to me that I am still thinking in a NURBS workflow, so what I need to do is just do some research into other mechanical polygon models to see how others have handled similar situations.

02 February 2005, 11:30 PM
Consider how groups of edges can define a plane. Then consider how their proximity to each other affects the smoothing tension. If you were to pull the new edges running across the center out a bit it might look better. Just watch out for artifacts that might occur on the n-gon areas that are likely to happen during triangulation for rendering. I hope that makes enough sense to be useful.

02 February 2005, 11:03 AM
i would advice looking through the sub-d thread, in this modelling section, it has all your answers there.

you basicly have to model the holes, not just cut them in, you will get a good smoothed mesh at the end. Maybe it would been best starting somewhere,instead of doig the whole shape in on time.

but take a look in that thread. it will help you lots

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