Justin and others,
You mentioned that sending the triangles every frame to the hardware is not GPU friendly, because they must be clipped and culled every frame. However, for a GPU, isn't this done in hardware anyway? (According to NVIDIA's semi-official definition, a GPU has hardware T&L.)
Of course, you are still *sending* the geometry every frame anyway, which can be expensive (even if the geometry is processed on the GPU). So is there a way to implement a dynamic terrain rendering system that does not require sending the data to the GPU every frame? ("dynamic" meaning that the data varies depending on viewer location)
Even if the data is not dynamic, can other techniques be used to dump all the data to the graphics card and keep it there? Perhaps display lists, or higher-order surfaces? And since this is the Java 3D list, can any of this be done with Java 3D?
Just some questions to keep the ol' brain cells firing. :)
- Mauricio
-----Original Message-----
From: Justin Couch [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, February 05, 2002 5:58 PM
To: [EMAIL PROTECTED]
Subject: Re: [JAVA3D] ROAM (was Re: [JAVA3D] need help on view frustrum
culling !!!)
Kevin J. Duling wrote:
> I'm under the impression that ROAM is CPU intensive and not very
> GPU-friendly.
Correct, sorta. At least here on this laptop (ATI Rage M3/833Mhz CPU) it
seems to run reasonably well with the small terrains I'm testing on. Not
sure what is taking the CPU time, but j3D always runs as fast as
possible anyway with 100% usage. GPU friendly it is not as it sends new
triangles to the card every time the viewpoint moves. Those triangles
need to be clipped & culled for each frome, so at least the GPU has
something to do :) So, yes, most of it is CPU bound, not using the
hardware. However, throw some textures over the top and you'll keep the
GPU happy for as long as it likes....
> I've done some reading into both ROAM and VIPM. I haven't yet implemented
> either, but I've read a few articles recommending VIPM over ROAM.
Well, I'm taking the slut approach here - Paul sent us the ROAM code, so
that's what I'm working with. Didn't bother looking into anything else
at this stage. Once I get the ROAM done, I'll start up the terrain list
and we can go from there discussing other algorithms and optimisations
that could be done. Expect that to happen around the end of the week.
--
Justin Couch http://www.vlc.com.au/~justin/
Freelance Java Consultant http://www.yumetech.com/
Author, Java 3D FAQ Maintainer http://www.j3d.org/
-------------------------------------------------------------------
"Humanism is dead. Animals think, feel; so do machines now.
Neither man nor woman is the measure of all things. Every organism
processes data according to its domain, its environment; you, with
all your brains, would be useless in a mouse's universe..."
- Greg Bear, Slant
-------------------------------------------------------------------
===========================================================================
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".
