marching cubes and shared points between cubes

marching cubes and shared points between cubes

Post by Gorm David La » Wed, 02 Dec 1998 04:00:00



 I have just implemented the marching cubes algorithm, but it generates
 an excessive amount of points.
 Finding shared points and edges locally within each cube is trivial
 because of the edge table used.
 What I cannot figure out, is how to calculate shared points and edges
 between adjacent cubes. All points calculated lie on the edges of the
 cube, which means that, a point can be shared by up to four cubes (this
 would almost never happen in reality).
 If anyone got a realtime solution that solves this problem, I would be
 grateful if they would share it with me.

--
-Gorm Lai aka. Pharao^Cromatics--
    2nd year CS & Math Student
http://www.daimi.aau.dk/~pharao/

 
 
 

marching cubes and shared points between cubes

Post by Andrea Bottin » Thu, 03 Dec 1998 04:00:00




>  I have just implemented the marching cubes algorithm, but it generates
>  an excessive amount of points.
>  Finding shared points and edges locally within each cube is trivial
>  because of the edge table used.
>  What I cannot figure out, is how to calculate shared points and edges
>  between adjacent cubes. All points calculated lie on the edges of the
>  cube, which means that, a point can be shared by up to four cubes (this
>  would almost never happen in reality).

I use a point table, an edge table and a cube table. An edge belonging to
multple cubes is not replicated several times but has a single entry into
the edge table (cubes have references to the edges and vertices, edges have
references to the extreme points). So when you evaluate one subdivision for
an edge just switch a flag on and first time you use a cube sharing the same
edge (since you have a reference) you just have to check the flag and get
the subdivision point found (that is an entry into the points table).

Hope this help.

--
Andrea Bottino
Politecnico di Torino, DAUIN
Corso Duca degli Abruzzi, 24
10129 Torino ITALY
Tel +39 011 5647084 / Fax +39 011 5647099
http://www.polito.it/~bottino

 
 
 

1. Seed cubes for marching cube

Hello everyone,

I am writing a code to build Isosurfaces using marching cube method. My
question is if there is an algorithm of finding "seed cubes" with
constant or linear time.  Specificly, I have a "ni" by "nj" by "nk" grid
and a surface intersecting it. How to find the first cube intersected by
the surface with constant or linear time?

Any of your suggestion is appreciated.

Xinlong Wang

2. letterbox effect

3. looking for source to the cube (Rubik's cube) demo

4. Rotate Shape ?? How ??

5. A source code of Rubik's Cube (aka The Hungarian Cube)

6. Other Colors are used after Mybitmap.Palette := CreatePalette()

7. Question: Edge-Cube-, Triangle-Cube-Intersection

8. Graphics courses

9. PROG: kurbik's cube (variable size rubik's cube)

10. d3d: i got a cube (cube.x) but how do i translate/move it

11. Marching Cubes Implementation ??

12. marching cubes

13. Need 3D Medical data sets to check my implementation of the Marching cubes