Geometry Shaders for Irrlicht(development closed till later)

[sudi]

doesn't compile on my gpu...you have a video?

[vectorcorpse]

AMD Athlon 64 x2 4800+ skt939
2Gb ddr1 dual channel
saphire ATI radeon HD4850
on ubuntu 9.10

• Welcome to the irrlicht example number 24
  "Geometry Shaders" which will show you
  the capabilities of irrlicht's shaders in
  addition to relief mapping
  Irrlicht Engine version 1.7.1
  Linux 2.6.31-20-generic #57-Ubuntu SMP Mon Feb 8 09:02:26 UTC 2010 x86_64
  Creating X window...
  Visual chosen: : 41
  Using renderer: OpenGL 3.2.9551
  ATI Radeon HD 4800 Series: ATI Technologies Inc.
  OpenGL driver version is 1.2 or better.
  GLSL version: 1.5
  Reading material file: room_tesselation.mtl
  Could not open material file: room_tesselation.mtl
  Loaded material start: _--_default_--
  Loaded smoothing group start: 1
  Loaded smoothing group start: off
  Loaded smoothing group start: 1
  Loaded smoothing group start: off
  Loaded smoothing group start: 1
  Loaded mesh: ../../media/room_tesselation.obj
  Loaded texture: /home/ricardo/dev/irrlicht-1.7.1/media/rockwall_height.bmp
  Loaded texture: /home/ricardo/dev/irrlicht-1.7.1/media/rockwall.jpg
  GLSL shader failed to compile
  Geometry shader failed to compile with the following errors:
  ERROR: 0:78: error(#132) Syntax error: '}' parse error
  ERROR: error(#273) 1 compilation errors. No code generated

this is a really strange error since on line 78 the '}' looks fine to me
btw: u didn't include the material file for the room model in the zip file

[vectorcorpse]

for those who want something more visual u can see tessellation working on unigine with and without
http://www.youtube.com/watch?v=bkKtY2G3FbU
and here the full demo
http://www.youtube.com/watch?v=9F6zSgtRnkE
this is good for a big range of machine in a game support
u can have a low polly model for older cards and for the newer cards u can add geometry detail using mapping in a similar way that we do with parallax but instead of moving lights u add triangles

[stefbuet]

Wooo this is nice!
For people who can't compile it, I'm going to upload a video.
Just wait 1h40 more and it will be ready...

By the way, nice work

[Virion]

http://www.youtube.com/watch?v=fEC0WAF2NIg

I can see that tessellation is useful for example for the flag and water but I don't see any real advantage on the crowd though... doesn't look any better.

anyway unigine's demo is really cool i like that.

[hybrid]

stefbuet, you got this example to compile? Neither my Mac nor my PC with ATI HD card could compile it. I'll try next week on a nv 8800, but don't know if it supports geometry shaders...

[Nadro]

stefbuet, you got this example to compile? Neither my Mac nor my PC with ATI HD card could compile it. I'll try next week on a nv 8800, but don't know if it supports geometry shaders...

Each graphic card compatible with DX 10 (so GF8800 also) support GS also in OGL, only problem will be performance...

[stefbuet]

Here is the video:
http://www.youtube.com/watch?v=zMMXvjlZ_s8

You can see the room with a lot lot of tesselletion at 1:48
And it's rendered on a GeForce GTX 260

[hybrid]

Well, neither the Intel card (which exposed the geometry shader4 extension) nor the ATI card did compile the shader. So I'll put my hopes on the nvidia compiler...

[stefbuet]

As the mesh used in the demo wasn't so great, I used another one which is really cool with the heightmap. It's like in the previous post about Heaven engine with the paved roads demo.

Here is a little screen shot:


Wireframe:

[hybrid]

Did you use the same geom shader? Could you provide the mesh, we'd like to add a new example for geometry shaders. And this example looks exactly like what we want

[stefbuet]

I used the same shaders.
I just changed some few things:
-added return(false) to the event receiver
-commented the GUI window creation, because when deleted, the screen was darker than what it should be... Idk why.
-changed default parameters to make the whole thing cool as soon as you execute the demo (wireframe desabled, ...)

The mesh is a plane create in 3dsmax (.max in archive) with 6*6 subdivisions, and tex coords.
The texture and heightmap are from http://www.filterforge.com/filters/
(I also photoshoped a little the heightmap to make it woking better)

Here is the archive with sources, assets and binary (without irr 1.7.1 dll):
http://dl.free.fr/aCJCEmUXG

[sudi]

when i try to run the example 24 i get this in the console

Code: Select all

Welcome to the irrlicht example number 24
"Geometry Shaders" which will show you
the capabilities of irrlicht's shaders in
addition to relief mapping
Irrlicht Engine version 1.7.1
Linux 2.6.31-19-generic #56-Ubuntu SMP Thu Jan 28 02:39:34 UTC 2010 x86_64
Creating X window...
Visual chosen: : 39
Using renderer: OpenGL 3.0.0
GeForce 8600M GT/PCI/SSE2: NVIDIA Corporation
OpenGL driver version is 1.2 or better.
GLSL version: 1.3
Could not load mesh, because file could not be opened: : ../../media/room_tesselation.obj
GLSL shader failed to compile
0(180) : error C7532: global function min requires "#version 130" or later

Segmentation fault

PS: i tried the nvidia demo about openGl tessalation and it worked so i guess its not my videocard?!

[Virion]

stefbuet your demo looks cool.[/quote]

[devsh]

nice job at presenting my idea

If I manage to get some more free time, I will work on a version which doesn't have these ugly holes between LoD levels (I didn't have adjacency info).

Also add Parallax Occlusion mapping to the demo on top of the tesselation

also there can be one more example of this feature, phong tesselation, subdivides mesh only on edges to the screen to achieve e.g. a pixel perfect round ball. Again I could write it, with some time.



this is not so much of a FPS killer as normal tesselation, meaning it actually has a use on dx10 hardware.