I'm also learning how to do this. Of all the different ways of generating
terrain, the heightmap seems to be the easiest.
David Yazel had some interesting posts on this subject about 6 months ago.
If you check the archives, you can read about some of his findings. Perhaps
we could encourage him to write a tutorial in his non-existant spare time.
*grin*
Drawing a heightmap with a few TriangleStripArray objects seems to be pretty
straightforward. And yes, I do think you need to do one strip per row. I
saw an interesting article on how to do this with only one triangle strip at
http://www.psky.com/prog/mesh_1.htm but I don't trust it. It seems to me
you'd get some very undesirable effects on your boundaries. And given that
you still have to go back down the row, I don't see a substantial vertex
savings. And drawing a texture to go over that kind of terrain would be
difficult.
Drawing a 256x256 heightmap generates an unmanageable amount of triangles
(something near 65,000). So I want to do some sort of LOD management. I'm
currently experimenting with breaking the heighmap up into square cells.
Each cell would have a LOD. For example, a 9x9 grid of cells, with the
camera in the center, may look like this:
111111111
111111111
112222211
112333211
112343211
112333211
112222211
111111111
111111111
Each number represents a polygon count for that cell. 1 might represent 2
triangles, 4 might hold 64 triangles. As the camera moves from one cell to
another, the LOD changes for all the cells surrounding the camera. The
biggest problem I see is stitching the cells together.
I'm not sure whether it would be better to generate the LOD values from the
256x256 heightmap, or store each cell's LOD on disk. Generating seems
easiest, but more prone to error. Storing each cell would allow me to tweak
any values by hand, but seems like it could quicky become a nightmare to
maintain.
I'd really like to hear how others have done this. I'm not sure I'm on the
right track.
----- Original Message -----
From: "Quoc Huynh" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, June 01, 2001 1:49 AM
Subject: [JAVA3D] Elevation Grid
> Hi All,
>
> I just wanted to know what is the best approach at drawing an
elevation grid?
>
> I have a 250x213 matrix contain heights... an (x,y) matrix. with
the
> height as the z component. I have no further information.
>
> I'm looking at using the trianglestrip geometry array, however,
does this
> mean i need to create a trianglestrip array for each row of my grid??...
> this would also mean i will be reproducing some shared points between
> triangle strips???
>
> does anyone know a better approach to this?????
>
>
>
> cheers,
>
>
> Quoc.
>
>
===========================================================================
> To unsubscribe, send email to [EMAIL PROTECTED] and include in the
body
> of the message "signoff JAVA3D-INTEREST". For general help, send email to
> [EMAIL PROTECTED] and include in the body of the message "help".
_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff JAVA3D-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
