Core77

"Bendsketch" Software Turns a 2D Sketch into a 3D Model

All you need to add is simple contour lines

By Rain Noe - May 8, 2017

in Sketching | Process

At design school we're taught to sketch 3D objects on 2D paper, using contour lines to convey three dimensionality to the viewer. But what if those contour lines, rather than serving as visual suggestions, actually served as instructions to a modeling program? In what has to be the most minimalist form of input we've ever seen, a group of researchers has actually worked that out.

A collaboration between the University of Hong Kong, Microsoft Research Asia and the University of British Columbia has yielded "BendSketch: Modeling Freeform Surfaces Through 2D Sketching," a paper presented at this year's SIGGRAPH. Here's how it works:

Enter a caption (optional)

To model a desired surface patch with our technique, the user sketches the patch boundary as well as a small number of strokes representing the major bending directions of the shape. Our method uses this input to generate a curvature field that conforms to the user strokes and then uses this field to derive a freeform surface with the desired curvature pattern. To infer the surface from the strokes we first disambiguate the convex versus concave bending directions indicated by the strokes and estimate the surface bending magnitude along the strokes. We subsequently construct a curvature field based on these estimates, using a non-orthogonal 4-direction field coupled with a scalar magnitude field, and finally construct a surface whose curvature pattern reflects this field through an iterative sequence of simple linear optimizations.

Enter a caption (optional)

Anyone smell a bidding war between the major software companies?

o
1

Favorite This
Q
2

Comment

Comments

Eric Strebel

7 years ago

Z

2Z

Reply

Neat, Except I don't draw or sketch that way. Bizarre that you would design a product where the user has to adjust the way they perform their work flow, that is just not good design. Curious if they even consulted with a designer that knows how to sketch?

It reminds me a little bit of some of the old videos about "EverybodyLovesSketch" https://www.youtube.com/watch?v=hGmE362ldZY&t=7s

I get that this is a concept, and they needed a way to work out the contours.
Take the bird for example. I would draw the top and the bottom of the bird twith a series of strokes then add the feet. Then perhaps the detail of the wing.
Makes me think the target audience is people that don't know how to draw at all. Why would that audience need 3D CAD models??? My guess is that they are not targeting designers, or did not do their homework or did not have access to designers with decent drawing skills.
As a designer you do need to know how to express/represent your own concepts by yourself and not have someone else interpret your sketches or hand waving. Such as what we see on HGTV. Appalling to watch those interior designers, they don't ever sketch out their own ideas in 2d or 3d, they have someone else model their stuff and go "yeah thats what I meant".
This seems super dangerous for students as well, imagine if students used a tool like this and relied on it instead of learning how to draw and understanding the fundamentals of 2 and 3 point perspective.

It could be a useful tool however, It certainly would make the transition from sketch to 3D CAD a bot less painless if it could be implemented in a streamlined manner.

!Report as spam
Rudy Joseph

7 years ago

Z

Z

Reply

This is actually pretty cool. Anyone who does 3D modelling knows that creating accurate depth is one of the more tedious aspects of blocking. Learning how to draw in the way the computer recognizes doesn't look too difficult to learn.

!Report as spam