Comments for Code Laboratorium http://codelab.wordpress.com Musings of a grumpy coder Mon, 09 Nov 2009 01:06:14 +0000 http://wordpress.com/ hourly 1 Comment on FreeGLUT spaceball patch by Nuclear http://codelab.wordpress.com/2009/10/16/freeglut-spaceball-patch/#comment-84 Nuclear Mon, 09 Nov 2009 01:06:14 +0000 http://codelab.wordpress.com/?p=91#comment-84 The patch has been commited to the freeglut subversion repository (rev 837 and up), and should make it into the next freeglut 2.6.0 release (which I understand should be out shortly). Btw, where freeglut is installed can be controlled by passing the --prefix=/what/ever/path argument to the configure script. However /usr/local/include should be in the default search path. At least it is on my system. The patch has been commited to the freeglut subversion repository (rev 837 and up), and should make it into the next freeglut 2.6.0 release (which I understand should be out shortly).

Btw, where freeglut is installed can be controlled by passing the –prefix=/what/ever/path argument to the configure script. However /usr/local/include should be in the default search path. At least it is on my system.

]]> Comment on FreeGLUT spaceball patch by Guillaume Riviere http://codelab.wordpress.com/2009/10/16/freeglut-spaceball-patch/#comment-82 Guillaume Riviere Tue, 03 Nov 2009 03:25:34 +0000 http://codelab.wordpress.com/?p=91#comment-82 PS: 1) On this page http://spacenav.sourceforge.net/glut/ you should precise that the patch must be copied and applied in the "freeglut" directory (obtained from svn) 2) The command "make install" installs freeglut in /usr/local/ then -I /usr/local/include must be added to gcc or g++ PS:
1) On this page http://spacenav.sourceforge.net/glut/
you should precise that the patch must be copied and applied in the “freeglut” directory (obtained from svn)

2) The command “make install” installs freeglut in /usr/local/
then -I /usr/local/include must be added to gcc or g++

]]> Comment on FreeGLUT spaceball patch by Guillaume Riviere http://codelab.wordpress.com/2009/10/16/freeglut-spaceball-patch/#comment-81 Guillaume Riviere Tue, 03 Nov 2009 03:14:21 +0000 http://codelab.wordpress.com/?p=91#comment-81 Hello, Thank you so much !!! I want to develop a GLUT application under Debian Lenny and to use the SpacePilot of 3D Connexions. Then i needed the 3 functions glutSpaceballButtonFunc(), glutSpaceballMotionFunc () and glutSpaceballRotateFunc (), which are not (yet) implemented in FreeGLUT. Current version is 833, the command to download should now be: svn co https://freeglut.svn.sourceforge.net/svnroot/freeglut/trunk/freeglut/freeglut -r 832 Thanks again for your great work ! Hope FreeGLUT will add your patch to official version. Guillaume Hello,

Thank you so much !!! I want to develop a GLUT application under Debian Lenny and to use the SpacePilot of 3D Connexions.

Then i needed the 3 functions glutSpaceballButtonFunc(), glutSpaceballMotionFunc () and glutSpaceballRotateFunc (), which are not (yet) implemented in FreeGLUT.

Current version is 833, the command to download should now be:

svn co https://freeglut.svn.sourceforge.net/svnroot/freeglut/trunk/freeglut/freeglut -r 832

Thanks again for your great work ! Hope FreeGLUT will add your patch to official version.

Guillaume

]]> Comment on S-ray goes public by giannis http://codelab.wordpress.com/2009/10/04/s-ray-goes-public/#comment-78 giannis Sun, 18 Oct 2009 19:17:30 +0000 http://codelab.wordpress.com/?p=85#comment-78 Congratulations! Can't wait to see where you are heading with this! But the sooner you have easy downloadable/installable packages the sooner you get feedback. ;) Congratulations!

Can’t wait to see where you are heading with this! But the sooner you have easy downloadable/installable packages the sooner you get feedback. ;)

]]> Comment on Spacenavd 0.4 by modal http://codelab.wordpress.com/2009/07/24/spacenavd-0-4/#comment-68 modal Sun, 26 Jul 2009 22:26:05 +0000 http://codelab.wordpress.com/?p=67#comment-68 Great stuff man!! Love the new website as well :-) The blue grid in the background reminded me of: http://www.youtube.com/watch?v=zowhg6l9RUc Great stuff man!!

Love the new website as well :-)
The blue grid in the background reminded me of:

]]> Comment on Sray raytracer under development by giannis http://codelab.wordpress.com/2009/06/12/sray-raytracer-under-development/#comment-54 giannis Sun, 21 Jun 2009 18:56:27 +0000 http://codelab.wordpress.com/?p=61#comment-54 Ok, good to know - please keep us updated with your work! :) Ok, good to know – please keep us updated with your work! :)

]]> Comment on Sray raytracer under development by Nuclear http://codelab.wordpress.com/2009/06/12/sray-raytracer-under-development/#comment-53 Nuclear Sun, 21 Jun 2009 03:27:48 +0000 http://codelab.wordpress.com/?p=61#comment-53 For the moment I'm just having fun with it, plus it's my MSc dissertation project. I will definitely release it when it's close to usable, but whether I'll carry on development and make it into something considered "production quality" in terms of features and performance, remains to be seen :) For the moment I’m just having fun with it, plus it’s my MSc dissertation project.
I will definitely release it when it’s close to usable, but whether I’ll carry on development and make it into something considered “production quality” in terms of features and performance, remains to be seen :)

]]> Comment on Sray raytracer under development by giannis http://codelab.wordpress.com/2009/06/12/sray-raytracer-under-development/#comment-52 giannis Sat, 20 Jun 2009 21:48:18 +0000 http://codelab.wordpress.com/?p=61#comment-52 It looks good John ;) Is SRay going to be an educational tool of yours, or are you heading for a production ray-tracer? It looks good John ;)

Is SRay going to be an educational tool of yours, or are you heading for a production ray-tracer?

]]> Comment on Sray raytracer under development by Nuclear http://codelab.wordpress.com/2009/06/12/sray-raytracer-under-development/#comment-51 Nuclear Sun, 14 Jun 2009 06:40:59 +0000 http://codelab.wordpress.com/?p=61#comment-51 smathegreek: I'm not sure about any tutorials, but I could suggest a book: "An Introduction to Ray Tracing" ( http://www.amazon.com/Introduction-tracing-Kaufmann-Computer-Graphics/dp/0122861604 ). Unfortunately I just noticed it's quite expensive, but no matter, actually I can explain how to write a simple ray tracer in a few sentences. The algorithm is extremely simple and elegant. For each pixel of the image, you start by generating a ray that starts from the view point, and passes through that pixel. Then you have to test that ray with all objects in the scene and find the closest intersection point (start by supporting only spheres and infinite planes which are the simplest objects to test for intersections). If there is no intersection, just assign black, or whatever you consider the "background" color to that pixel. Otherwise, at the closest intersection, calculate the color using the standard phong reflectance model and assign that to the pixel. Adding reflections is trivial. At the intersection point, recursively call the ray tracing routine with a new ray which has that point as its origin, and direction equal to the reflected vector of the original ray by the normal, and just add the color it returns to the calculated direct color, multiplied by the "reflectivity" of the object. Refraction and shadows are equally trivial if you think about it. Have fun, and let me know if you give it a try, and ask if you have any problems :) smathegreek: I’m not sure about any tutorials, but I could suggest a book: “An Introduction to Ray Tracing” ( http://www.amazon.com/Introduction-tracing-Kaufmann-Computer-Graphics/dp/0122861604 ). Unfortunately I just noticed it’s quite expensive, but no matter, actually I can explain how to write a simple ray tracer in a few sentences. The algorithm is extremely simple and elegant.

For each pixel of the image, you start by generating a ray that starts from the view point, and passes through that pixel. Then you have to test that ray with all objects in the scene and find the closest intersection point (start by supporting only spheres and infinite planes which are the simplest objects to test for intersections). If there is no intersection, just assign black, or whatever you consider the “background” color to that pixel. Otherwise, at the closest intersection, calculate the color using the standard phong reflectance model and assign that to the pixel.

Adding reflections is trivial. At the intersection point, recursively call the ray tracing routine with a new ray which has that point as its origin, and direction equal to the reflected vector of the original ray by the normal, and just add the color it returns to the calculated direct color, multiplied by the “reflectivity” of the object. Refraction and shadows are equally trivial if you think about it.

Have fun, and let me know if you give it a try, and ask if you have any problems :)

]]> Comment on Sray raytracer under development by smathegreek http://codelab.wordpress.com/2009/06/12/sray-raytracer-under-development/#comment-50 smathegreek Sun, 14 Jun 2009 01:22:55 +0000 http://codelab.wordpress.com/?p=61#comment-50 Gianni poly entypwsiako !!! Mporeis na postareis kapoio link gia tutorials pou aforoun raytraces klp ??? Gianni poly entypwsiako !!!
Mporeis na postareis kapoio link gia tutorials pou aforoun raytraces klp ???

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