lhf
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Why are Homogeneous Coordinates used in Computer Graphics?
15 votes

They simplify and unify the mathematics used in graphics: They allow you to represent translations with matrices. They allow you to represent the division by depth in perspective projections. The ...

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Is there some kind of Bresenham algorithm or equivalent for scanline rendering a rotated ellipse?
9 votes

The classic book Computer Graphics: Principles and Practice (second edition) by Foley, van Dam, et al. describes such an algorithm in section 19.2. The explanation in the book seems to come from an ...

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Why do T-junctions in meshes result in cracks?
9 votes

When modeling parametric surfaces with a mesh in the parameter domain, T-junctions will most probably appear as discontinuities in the surface. These will show up as gaps in the rendering. See below. ...

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Ordering a set of unorganized points along a curve
6 votes

You have an instance of a problem called curve reconstruction from unorganized points. Now that you know what to search for you'll find several methods, such as the crust, NN-crust, etc. Here are a ...

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Strategy for connecting 2 points without intersecting previously drawn segments of curves
6 votes

The general problem is called graph drawing and is not an easy problem. The graphs that can be drawn on the plane without crossings are called planar, but not all graphs are planar: the typical graphs ...

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Two-dimensional bounded area defined parametrically
4 votes

One solution is bilinear mapping, which works for every convex quadrilateral. Let $A, B, C, D$ be the vertices of a quadrilateral $Q$ in the plane, in this order. Then $f(u,v)=(1-u)(1-v)A + u(1-v)B +...

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Changing image so it would look like through colorful glasses
3 votes

Choose the color RGB of your colorful glasses and choose how transparent they are by choosing an alpha value A. Then alpha composite the glasses on top of the input image: OutputR = R * A + InputR * (...

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How to crop with edge-detection using imagemagick
Accepted answer
2 votes

Try -trim instead of -shave: convert original.png -trim trimmed.png See the docs for this and other options.

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How can I concentrate points in areas of higher curvature?
2 votes

A good starting point is the classic paper Using particles to sample and control implicit surfaces, published in SIGGRAPH 1994. A simple particle simulation described in the paper Sampling implicit ...

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Is there an established method of approximating dust distribution on surfaces?
2 votes

See the paper Computer Modelling of Fallen Snow published in SIGGRAPH 2000: In this paper, we present a new model of snow accumulation and stability for computer graphics. Our contribution is ...

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Very efficient/fast marching cube implementation
0 votes

Try these papers: Octrees for faster isosurface generation by Wilhelms and Van Gelde (1992) Speeding up isosurface extraction using interval trees by Cignoni et al (1997) A survey of the marching ...

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