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Modding, Mission Design, and Coding => FS2 Open Coding - The Source Code Project (SCP) => Topic started by: Omniscaper on February 10, 2004, 09:33:26 pm

Title: Real time tesselation feasable?
Post by: Omniscaper on February 10, 2004, 09:33:26 pm
I was just curious. I've been researching how many PC/console games handle poly detail lateley and I came across Freespace2's LOD style, tesselation, and an upcoming nurbs process. I fired up Rogue Squadron for the game cube and scrutinized the models as I got closer. It uses on the fly tesselation (polygons subdivide smoothly) and it looks fantastic. It is a seamless transition. ::sigh::  :::goes back to playing Freespace2::

Would the integration of such a process require a complete overhaul of the game engine, or just some fancy Directx scripting? I recall a past thread about ATI's Truform. How did that go?


PS: I have read to my surprise that PSP (Playstation Portable) was announced to have a polygon AND seperate nurbs processor to cut down on data bandwidth. I don't know if this is PR bull, or a Sony achievement, but I think this will be a great stepping stone for realtime CG graphics. If they could do this in realtime vs 3dsmax's CPU killing nurbs, then I will be impressed.
Title: Real time tesselation feasable?
Post by: Bobboau on February 10, 2004, 09:47:44 pm
our N-patch test went very very well, the only problem is that ATI have droped suport for it so the drivers are going to make it less and less reliable, but it does generaly work, only problem is you will experience somewhat rare random crashes, but the performence is great and the look of the models is gorgus, wait for post 3.6 for this to be an implemented effect, the day 3.6 is pushed out I'll have it working in five minutes. but only for ATI cards, RT was working on a software version of it, but it wouldn't be dynamic and it wouldn't be as fast. the only major issue we had remaining was fixing cracks, but I had a good idea for fixing it just didn't spend the (htl debugging) time to implement it.
Title: Real time tesselation feasable?
Post by: Omniscaper on February 10, 2004, 10:50:20 pm
Do know if ATI's trueform took into account, smoothing groups? I fear that such a process, if not well optimized, would smoothe out the wrong things like right angle edges.

Has there been any builds in the past that had this implemented? Or were the threads I read just you programmers chewing the fat? Do you know which games utilize Trueform? I remember that function being an important selling point with ATI to battle against Nvidia. Now I really wanna see it in action.

Its a shame that they dropped it. This is news to me. It really doesn't make sense, unless they decided to concentrate on the cards brute strength instead of these types of shortcuts. I figured, if its a shortcut that WORKS then they must have come up with a better way of handling polygon detail transitions.
Title: Real time tesselation feasable?
Post by: Starks on February 10, 2004, 11:38:18 pm
Can someone please explain tesselation in laymans terms?
Title: Real time tesselation feasable?
Post by: Bobboau on February 10, 2004, 11:53:43 pm
the way I settled on implementing it kept the shape of the geometry, but subdivided it and interpalated the normals of the geometry in such a way that it looked like it was nurbed (exept on the edges of the geometry)
it did take into acount smoothing groupes, but it caused cracks, which is the issue I was trying to solve
Title: Real time tesselation feasable?
Post by: Carl on February 11, 2004, 12:51:11 am
http://www.hard-light.net/forums/index.php/topic,19133.0.html
Title: Real time tesselation feasable?
Post by: Omniscaper on February 11, 2004, 02:56:10 am
Bummer, I guess ATI's latest drivers don't utilize Trueform or that last ATI build was written for a different set of drivers. Oh well. Its not like my Trek ships need it anyways, but those sceenies sure made Freespace ships look sweet.
Title: Real time tesselation feasable?
Post by: Kazan on February 11, 2004, 07:16:42 am
not enough people used truform
Title: Real time tesselation feasable?
Post by: Bobboau on February 11, 2004, 07:24:27 am
which is lame, people said there too dificult to use, that's bull, it takes all of five minutes to implement it on a HT&L system
Title: Real time tesselation feasable?
Post by: Kazan on February 11, 2004, 07:27:56 am
that's because you have a decent ability to code
Title: Real time tesselation feasable?
Post by: Bobboau on February 11, 2004, 07:30:29 am
barely, anyone who has half an understanding of how to do anything in direct x could do it, the hardest part is figureing out wich render states to set, it's literealy a two line change to implement it (more lines make a better implementation, but all that's needed is the two lines)