1

ok ca marche smile
[edit]Edité par yAro le 20-01-2002 à 11:04:46[/edit]
avatarWebmaster et développeur du site. Pour tout probleme ou question envoyez un mini message ou mail.

Suivez l'actualité de tous vos site préférés sur yAronews : http://ns.yaronet.com =)

2

Puisqu'on est ici pour tester
Je pense que tu devrais limiter les posts à 5 ko, yAro
geological volume, for example.

References:
"Marching Cubes: A High Resolution 3D Surface Construction Algorithm",
William E. Lorensen and Harvey E. Cline,
Computer Graphics (Proceedings of SIGGRAPH '87), Vol. 21, No. 4, pp. 163-169.

[Watt:Animation] pp. 302-305 and 313-321
[Schroeder]
James Sharman's description: <A href="http://www.exaflop.org/docs/marchcubes">http://www.exaflop.org/docs/marchcubes</A>



----------------------------------------------------------------------
Subject 5.11: What is the status of the patent on the "marching cubes" algorithm?

United States Patent Number: 4,710,876
Date of Patent: Dec. 1, 1987
Inventors: Harvey E. Cline, William E. Lorensen
Assignee: General Electric Company
Title: "System and Method for the Display of Surface Structures Contained
Within the Interior Region of a Solid Body"
Filed: Jun. 5, 1985
<A href="http://www.patents.ibm.com/details?patent_number=4710876">http://www.patents.ibm.com/details?patent_number=4710876</A>

United States Patent Number: 4,885,688
Date of Patent: Dec. 5, 1989
Inventor: Carl R. Crawford
Assignee: General Electric Company
Title: "Minimization of Directed Points Generated in Three-Dimensional
Dividing Cubes Method"
Filed: Nov. 25, 1987
<A href="http://www.patents.ibm.com/details?patent_number=4885688">http://www.patents.ibm.com/details?patent_number=4885688</A>


----------------------------------------------------------------------
Subject 5.12: How do I do a hidden surface test (backface culling) with 3d points?

Just define all points of all polygons in clockwise order.

c = (x3*((z1*y2)-(y1*z2))+
(y3*((x1*z2)-(z1*x2))+
(z3*((y1*x2)-(x1*y2))+

x1,y1,z1, x2,y2,z2, x3,y3,z3 = the first three points of the
polygon.

If c is positive the polygon is visible. If c is negative the
polygon is invisible (or the other way).


----------------------------------------------------------------------
Subject 5.13: Where can I find algorithms for 3D collision detection?

Check out "proxima", from Purdue, which is a C++ library for 3D
collision detection for arbitrary polyhedra. It's a nice system;
the algorithms are sophisticated, but the code is of modest size.

<A href="ftp://ftp.cs.purdue.edu/pub/pse/PROX/prox9.1.tar.Z">ftp://ftp.cs.purdue.edu/pub/pse/PROX/prox9.1.tar.Z</A>

For information about the I_COLLIDE 3D collision detection system
<A href="http://www.cs.unc.edu/~geom/I_COLLIDE.html">http://www.cs.unc.edu/~geom/I_COLLIDE.html</A>

"Fast Collision Detection of Moving Convex Polyhedra", Rich Rabbitz,
Graphics Gems IV, pages 83-109, includes source in C.

SOLID: "a library for collision detection of three-dimensional
objects undergoing rigid motion and deformation. SOLID is designed to
be used in interactive 3D graphics applications, and is especially
suited for collision detection of objects and worlds described in VRML.
Written in standard C++, compiles under GNU g++ version 2.8.1 and
Visual C++ 5.0." See:
<A href="http://www.win.tue.nl/cs/tt/gino/solid/">http://www.win.tue.nl/cs/tt/gino/solid/</A>

SWIFT: a C++ library for collision detection, exact and approximate
distance computation, and contact determination of three-dimensional
polyhedral objects undergoing rigid motion.
Some preliminary results indicate that it is faster than I-COLLIDE and
V-CLIP, and more robust than I-COLLIDE.
<A

3





Some older references:

An expensive answer:
@InProceedings{mitchell-1992-illumination,
author = "Don P. Mitchell and Pat Hanrahan",
title = "Illumination From Curved Reflectors",
year = "1992",
month = "July",
volume = "26",
booktitle = "Computer Graphics (SIGGRAPH '92 Proceedings)",
pages = "283--291",
keywords = "caustics, interval arithmetic, ray tracing",
editor = "Edwin E. Catmull",
}

A cheat:
@Article{inakage-1986-caustics,
author = "Masa Inakage",
title = "Caustics and Specular Reflection Models for
Spherical Objects and Lenses ",
pages = "379--383",
journal = "The Visual Computer",
volume = "2",
number = "6",
year = "1986",
keywords = "ray tracing effects",
}

Very specialized:
@Article{yuan-1988-gemstone,
author = "Ying Yuan and Tosiyasu L. Kunii and Naota
Inamato and Lining Sun ",
title = "Gemstone Fire: Adaptive Dispersive Ray Tracing
of Polyhedrons",
year = "1988",
month = "November",
journal = "The Visual Computer",
volume = "4",
number = "5",
pages = "259--70",
keywords = "caustics",
}


----------------------------------------------------------------------
Subject 5.10: What is the marching cubes algorithm?

The marching cubes algorithm is used in volume rendering to
construct an isosurface from a 3D field of values.

The 2D analog would be to take an image, and for each pixel, set
it to black if the value is below some threshold, and set it to
white if it's above the threshold. Then smooth the jagged black
outlines by skinning them with lines.

The marching cubes algorithm tests the corner of each cube (or
voxel) in the scalar field as being either above or below a given
threshold. This yields a collection of boxes with classified
corners. Since there are eight corners with one of two states,
there are 256 different possible combinations for each cube.
Then, for each cube, you replace the cube with a surface that
meets the classification of the cube. For example, the following
are some 2D examples showing the cubes and their associated
surface.

- ----- + - ----- - - ----- + - ----- +
|:::' | |::::::neutral |:::: | | '::neutral
|:' | |::::::neutral |:::: | |. 'neutral
| | | | |:::: | |::. |
+ ----- + + ----- + - ----- + + ----- -

The result of the marching cubes algorithm is a smooth surface
that approximates the isosurface that is constant along a given
threshold. This is useful for displaying a volume of oil in a




Some older references:

An expensive answer:
@InProceedings{mitchell-1992-illumination,
author = "Don P. Mitchell and Pat Hanrahan",
title = "Illumination From Curved Reflectors",
year = "1992",
month = "July",
volume = "26",
booktitle = "Computer Graphics (SIGGRAPH '92 Proceedings)",
pages = "283--291",
keywords = "caustics, interval arithmetic, ray tracing",
editor = "Edwin E. Catmull",
}

A cheat:
@Article{inakage-1986-caustics,
author = "Masa Inakage",
title = "Caustics and Specular Reflection Models for
Spherical Objects and Lenses ",
pages = "379--383",
journal = "The Visual Computer",
volume = "2",
number = "6",
year = "1986",
keywords = "ray tracing effects",
}

Very specialized:
@Article{yuan-1988-gemstone,
author = "Ying Yuan and Tosiyasu L. Kunii and Naota
Inamato and Lining Sun ",
title = "Gemstone Fire: Adaptive Dispersive Ray Tracing
of Polyhedrons",
year = "1988",
month = "November",
journal = "The Visual Computer",
volume = "4",
number = "5",
pages = "259--70",
keywords = "caustics",
}


----------------------------------------------------------------------
Subject 5.10: What is the marching cubes algorithm?

The marching cubes algorithm is used in volume rendering to
construct an isosurface from a 3D field of values.

The 2D analog would be to take an image, and for each pixel, set
it to black if the value is below some threshold, and set it to
white if it's above the threshold. Then smooth the jagged black
outlines by skinning them with lines.

The marching cubes algorithm tests the corner of each cube (or
voxel) in the scalar field as being either above or below a given
threshold. This yields a collection of boxes with classified
corners. Since there are eight corners with one of two states,
there are 256 different possible combinations for each cube.
Then, for each cube, you replace the cube with a surface that
meets the classification of the cube. For example, the following
are some 2D examples showing the cubes and their associated
surface.

- ----- + - ----- - - ----- + - ----- +
|:::' | |::::::neutral |:::: | | '::neutral
|:' | |::::::neutral |:::: | |. 'neutral
| | | | |:::: | |::. |
+ ----- + + ----- + - ----- + + ----- -

The result of the marching cubes algorithm is a smooth surface
that approximates the isosurface that is constant along a given
threshold. This is useful for displaying a volume of oil in a

4

voila un post de 5k... c pas un peu court quand même??

5

euh c thibaut qui a proposé ca alors ralez pas tongue
avatarWebmaster et développeur du site. Pour tout probleme ou question envoyez un mini message ou mail.

Suivez l'actualité de tous vos site préférés sur yAronews : http://ns.yaronet.com =)

6

c trop court 5Ko ! Enfin de tte façon y'a tjrs moyen de flooder...

Regarde ton message sBibi : on en met 3 comme ça bout à bout et déjà c'est énorme !
avatarAll right. Keep doing whatever it is you think you're doing.
------------------------------------------
Besoin d'aide sur le site ? Essayez par ici :)

7

lol c'est pas à moi de décider au nom de tout le monde yAro.
avatarUn site complet sur lequel vous trouverez des programmes et des jeux pour votre calculatrice TI 89 / Titanium / 92+ / Voyage 200 : www.ti-fr.com.
Quelques idées personnelles ici.

8

bah de toute façon si on veut flooder, c pas obligé ke ce soit du texte roll

ba la preuv:

fuckkkk.gif

vous en mettez une dixaine bout à bout, et ça fait un truc impotable... :/

9

putain 5 Ko c'est minable !!!!!! ok y'a le serveur qui doit pas exploser mais bon ...

on peut même pas enchainer un ouuuuuuuuuuuuuuuuuuuuééééééééé. sad

10

par contre on peut enchaîner un....

fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif
fuckkkk.gif

11

et encor ça fé pas 5k grin