# Talk:Graphical projection

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## Oblique Projection

Note that a page needs creating on Oblique Projection and added as a link after "oblique Projection" on this page. Pat 23:17, 20 Feb 2004 (UTC)

Isn't Axonometric projection a sub-category under Orthographic projection? If so, it should be properly nested.67.170.168.214 06:43, 17 October 2006 (UTC)

## Planometric Projection

$\begin{bmatrix} x' \\ y' \\ z' \\ 1 \end{bmatrix} = \begin{bmatrix} \cos \frac {\pi}{4} & - \cos \frac {\pi}{4} & 0 & 0 \\ \sin \frac {\pi}{4} & - \sin \frac {\pi}{4} & 1 & 0 \\ 0 & 0 & 0 & 0 \\ 0 & 0 & 0 & 1 \end{bmatrix} \begin{bmatrix} x \\ y \\ z \\ 1 \end{bmatrix}$

Me121121 04:35, 4 September 2007 (UTC)

Got a reference for that? It looks like a kind of Oblique projection to me, in fact it's this one I think: --Allefant 09:19, 4 September 2007 (UTC)
Yes. That's it. But it's not the same as oblique. But I don't have any references, and I don't know how widely used it is. Yet I still learn it at school so I thought it should be included. Can't you use wherever you got that image as a reference? Me121121 09:42, 6 September 2007 (UTC)
So the fact that each 3d dimention is distorted equally (45 degree) means that accurate scale drawings can be made, because a 3d line of length x will always be projected as a 2d line of length cx, irrespective of the line's orientation. This feature makes Planometric images look ugly as sin, but also makes the projection notable. —Preceding unsigned comment added by Stestagg (talkcontribs) 14:26, 14 May 2008 (UTC)

The very first sentence of this article links to protocol. That is (of course!) a disambiguation page. I'd disambiguate if I were sure of which article to link to. Michael Hardy (talk) 20:16, 20 November 2008 (UTC)

## "General" Projection?

I don't see any reference to "general" projection. All I mean by the term is the act of projecting a point in n dimensions onto a space of m dimensions, where m < n. Standard 3D graphics pipelines (as described in this article, also in games, ray-tracing, etc) are the case where n = 3 and m = 2. Most likely, I'm not finding it because I just don't know the proper term to search for. -LesPaul75talk 00:33, 16 May 2009 (UTC)

Found it: Projection (linear algebra). Is it worth mentioning in the introduction (to "graphical projection") that that graphical projection is subset of this more general field? -LesPaul75talk 00:45, 16 May 2009 (UTC)
This seems like a personal point of view, that graphical projection is subset of this more general field? As far as I know graphical projection is a collection of methods, which principles have been developed in the projective geometry. -- Marcel Douwe Dekker (talk) 13:34, 16 May 2009 (UTC)
I don't think it's a matter of opinion, but I could be wrong. This page talks about different ways to take a 3-dimensional object and "project" it to form a 2-dimensional image. Projection (linear algebra) is about how to do exactly the same thing, but in N dimensions. Quote from Projection (linear algebra): "For example, the function which maps the point (x, y, z) in three-dimensional space R3 to the point (x, y, 0) is a projection onto the x-y plane." That's the mathematical description of all the projections discussed here. -LesPaul75talk 18:52, 18 May 2009 (UTC)