John F. Hughes

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Sketching communicates ideas rapidly through approximate visual images with low overhead (pencil and paper), no need for precision or specialized knowledge, and ease of low-level correction and revision. In contrast, most 3D computer modeling systems are good at generating arbitrary views of precise 3D models and support high-level editing and revision. The(More)
We present an interactive system that lets a user move and deform a two-dimensional shape without manually establishing a skeleton or freeform deformation (FFD) domain beforehand. The shape is represented by a triangle mesh and the user moves several vertices of the mesh as constrained handles. The system then computes the positions of the remaining free(More)
Nonphotorealistic rendering (NPR) can help make comprehensible but simple pictures of complicated objects by employing an economy of line. But current nonphotorealistic rendering is primarily a batch process. This paper presents a real-time nonphotorealistic renderer that deliberately trades accuracy and detail for speed. Our renderer uses a method for(More)
Fme-form defommtion (FFD) is a powerful modeting tool, but contmtling the shape of an object under complex deformations is often ~cult. ‘fhe interface to FFD in most conventional syetems simply mpments the unddying mathematics directly, ur3ent&acdbe deformations by manipulating control points. lhe difEculty in controlling shape precisely is largely due to(More)
We introduce SmoothSketch---a system for inferring plausible 3D free-form shapes from visible-contour sketches. In our system, a user's sketch need not be a simple closed curve as in Igarashi's Teddy [1999], but may have cusps and T-junctions, i.e., endpoints of hidden parts of the contour. We follow a process suggested by Williams [1994] for inferring a(More)
We present an interactive system for creating pen-and-ink-style line drawings from greyscale images in which the strokes of the rendered illustration follow the features of the original image. The user, via new interaction techniques for editing a direction field, specifies an orientation for each region of the image; the computer draws oriented strokes,(More)