XM Magdalena 3D print, GGeorgy (3D)
LC #42 Pipers Alley

View Full Version : Cleanly cutting curved holes into curved surfaces?

04-01-2011, 02:32 AM
This is more a general question on the techniques and work-flow people use to do this. It gets me every time. Im using poly modelling.

Ill try to give an example:

I have an aircraft with a smooth flowing fuselage. I want to cut an open door into the side of it. The top of the door opening is curved, its profile also has a slight curve, making it flush with the fuselage.

I cant seem to do this without totally distorting the geometry on the fuselage around the opening of the doorway. Its like I can either optimise the edge-flow to the door or the fuselage but not to both. How would you guys approach this?

The final application is for a game engine.

04-01-2011, 03:23 AM
probably get a better response in the modeling forum.

04-01-2011, 03:39 AM
Nurbs :D

But that opens a whole other can of worms.

04-01-2011, 04:58 AM
You could have a copy of the uncut fuselage and then reproject the cut fuselage back to the original one thus preserving the shape.

04-01-2011, 09:01 AM
Booleans are your best bet. You will need to clean up afterwards, maybe some more cuts.
Other way would be planning the topology with the door in mind right from the beginning.

I don't know how much you should worry about that, with textures and lighting you can hide the distortion. Depends how shiny it is.

04-01-2011, 04:07 PM
Maya 2012 will have the ability to project curves onto poly surfaces which makes this easy. In the meantime try the polyNurbsIntersect.mel at creative crash (it's awesome).


04-01-2011, 04:19 PM
Thanks guys some really good suggestions. Pete i will look into that seems like a really good tool, cheers.

04-01-2011, 04:32 PM
Depending on your needs of your model (if it deforms or not) and what renderer you are using you can do clean holes with Constructive Solid Geometry (CSG) features with some renderers (rman etc) which will perform perfect booleans at render time.

04-01-2011, 05:21 PM
There are indeed hundreds of ways to solve this. Your best bet is to post an image of what you are doing and what you want and post it in the modeling area where I will move this.

04-03-2011, 03:35 AM
I hope this is of some help:

http://img716.imageshack.us/img716/6867/curvedsurfacedoortutori.jpg (http://img716.imageshack.us/i/curvedsurfacedoortutori.jpg/)

04-03-2011, 04:01 PM
Damnit, I was reading down this thread and was surprised nobody had put forward a certain method... I was looking forward to helping! But, Arrimus' way is the way I do it, the only difference is I tend to draw my initial shape with a spline.

04-03-2011, 04:23 PM

Now do a surface analysis of that :)
That will tell if the surface cut is well done or not.

1-Put a long thin cylinder in front of it.
2-make the ball and the ball door with same material with big reflection property.

If the reflection of the tube in ball and in ball door is continuous and with same flowing the surface was well cut.

Or you can do the professional way with a zebra analysis.

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