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Dersu's picture

Open Tk - Function graphs with correct axis

Posted Monday, 12 November, 2012 - 17:59 by Dersu in

Hi All,
I'm using OpenTK with VB.NET to plot a 3D graphs of a 2 variables function. I need to draw some axis around my figures.
I've drawn a wire box around my plot (like this figures taken from Wolfram Mathematica, for example)

but I'm not able to show numbers along axis and resize/reposition them correctly (as in the figure).

Is there any suggestion, please? Thank you!

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jrwatts's picture

Re: Open Tk - Function graphs with correct axis

Posted Monday, 12 November, 2012 - 21:01 by jrwatts

You could try QuickFont (search for it on this site; I tried including a link to it, but it didn't appear to work).

Dersu's picture

Re: Open Tk - Function graphs with correct axis

Posted Friday, 16 November, 2012 - 14:52 by Dersu

Thank you!
I've another question: how can I find the position of the projection? If I've a point of coordinates (x,y,z) how can I find what position (x-proj,y-proj) it will occupy on the screen?

golkeeper's picture

Re: Open Tk - Function graphs with correct axis

Posted Monday, 19 November, 2012 - 08:22 by golkeeper

multiply your coordinates by model, view and projection matrices (you can get them directly from opengl), than perspective divide the result and what you'll get would be normalized device coordinates, with x and y components providing desired position on screen (in -1..1 range)

Dersu's picture

Re: Open Tk - Function graphs with correct axis

Posted Monday, 19 November, 2012 - 13:51 by Dersu

Thank you golkeeper!
I found a partial way but your suggestion complete the solution.