edge-controlled surfaces

[Guest ghraben]

i am doing some non-architectural product modeling and have run into a situation where i want to have 2 surfaces bound together along an edge (like the edge of a box) and would like to control the common edge with a single control, like a bezier spline. is this possible?

 

would it be mesh, patch, or a nurbs solution?

 

if max can't, where should i look?

[Wolf]

All 3 would do the trick,

however without seeing an image or sketch of what you are doing, it would be hard to recommend 1 or the other :/

 

sub d modeling would give you control of the surface and edge.

patches would also,

and nurbs is also a good choice, as its non destructive modeling.

post a sketch, would be easier to help then

 

regards

Wolf

 

[ May 07, 2002, 09:17 PM: Message edited by: Wolf ]

[Guest ghraben]

here's a quickie 3-view of my project:

 

 

could you briefly explain "sub d"? or post some good linkage?

 

i have been using meshes, but i can't control the entire edge at once, just edges of the individual polys. i tried nurbs a bit, but i guess i'm still too new at it; i can't find out how to bind/join 2 surfaces' edges together.

 

i have 3 srufaces (front, back/side, and bottom), and 3 common edges. i'd like to control the surfaces with only 3 curves. right now, i'm regenerating the surfaces when i need to change the internal volume. each surface has to be lined up by hand with the others. uggh...

[Wolf]

Looking at your sketch, Nurbs is the way to go.

 

i am presuming by your last post that nurbs isnt your strong point

so sit tight, while i run you through a crash course

 

first we create the front left curve,

so go to curve...cv curve... and draw a cv curve using approx 3-5 cv's (CV stands for Control Vertices)

no need to be too pedantic, as the nature of nurbs let you readjust things later on.

 

rather than create that same curve again for the other side, in your nurbs control panel (pop up panel with green icons)

there is a button called "create mirror curve"

use that to create an instance for the other side

now both will update as the other gets changed.

 

Left viewport...draw the back curve the same way.

 

draw the bottom curve in left view and adjust it in top.

Create another mirror curve for the other side

 

and all thats left, is the front bottom curve, that you can draw in top view.

 

now attach all your working nurbs curves from the modifier panel

 

theres your outlines drawn

 

now for the fun part....

 

find a button on your nurbs control panel called..."create multi sided blend surface"

and now click on your front 3 curves and right click to finish....it should have now made a surface.

if you dont see it, it may have the normals flipped...so on your command panel there is a "flip normals" button

another method to avoid flipping normals, is to pick the lines in a different order (like counterclockwise)

nurbs normals are sensitive to creation order.

 

do that to all 4 faces

and your done

 

to change anything...you only need to adjust 1 curve, as the other side will be instanced, and the surface will update automatically

 

if you need more control on the curvature of the panels...you could add extra lines following the contour you want, and use "uv loft" instead

 

incase you got lost... here is a link to a simple file.

 

artistnation.com/members/paris/thewolfslair/nurbs_curves.zip

 

kind regards

Wolf

[Guest ghraben]

wow. thanks!! i tried this last night and it's exactly what i was looking for. thanks for the NURBS intro!

 

(you made the front page, too! )