From: Yair Kurzion (yair++at++polygon.engr.sgi.com)
Date: 02/02/2001 14:53:22
Hi Jan !
I believe adding a new case to the switch in setASDData:
case 3:
CLIP_TEXTURE = 1;
do_paging = 1;
break;
should work. This case is missing because we forgot. I think someone had to
add this in the past and it worked for them. If it doesn't work for you,
I can lookup that person.
Just a note: If your pageable ASD uses a round world model, you can not easily
map texture (or clip maps) on it. ASD pages the geometry of the terrain but
does not page texture coordinates per vertex. To add texture on a pageable ASD,
you have to use texgen. Lines 2-5 in the configuration file specify a matrix
for the texgen operation. Texgen defines a linear combination of vertex
coordinates that generate texture coordinates.
-yair
> I have written an utility to convert landscape elevation data into a
> pageable ASD (using ASDGen) and from what I could tell, the landscape
> although untextured seemed to be alright when viewed using ASDFly.
> Furthermore, I have written an utility to mipmap huge image and split it
> up a into tiles for use with the cliptexturing system of Performer. I
> have checked these files using ClipFly by writing the necessary .ic and
> .ct files and was quite astounded how well the cliptexture mapping
> system works.
> Now the big problem is how to combine the landscape model and the
> cliptextures that are to be laid on top of it. As far as I could tell,
> this is not possible using ASDFly, since you can only specify a pageable
> ASD along with a single .rgb texture, but not with cliptextures.
> Looking into the terrain.c source file of ASDFly, I saw that there are
> two flags that are set, depending on the mode specified in the
> configuration file (it is the first entry in the config file). The first
> flag specifies usage of a pageable ASD, the second specifies usage of
> cliptextures. My first attempt was to see, what happened if I enabled
> both of these at the same time, but that of course didn't work -- else
> it would probably already have been there.
> I hope that I don't have to rewrite the utilities, because working with
> such huge amounts of landscape data (600mb elevation data, 6gb
> photographs) it is very convenient to treat them separately.
> Any suggestions? Should I use other viewers than ASDFly?
>
> Thanks in advance,
> Jan Marguc
--
\_________ \_____ \__ \__ \_____ Yair Kurzion
\_________ \_____ \__ \__ \_____ yair++at++sgi.com
\__ \__ \____\__ \__ http://reality.sgi.com/yair
\__ \__ \__ Work: (650) 933-6502
\__ \__ \__ Home: (408) 226-9771
\__ \__ \__
This archive was generated by hypermail 2b29 : Fri Feb 02 2001 - 14:53:45 PST