10:22 
OpenGL
“OGLE (i.e. OpenGLExtractor) is a software package by Eyebeam R&D that allows for the capture and re-use of 3D geometry data from 3D graphics applications running on Microsoft Windows. It works by observing the data flowing between 3D applications and the system’s OpenGL library, and recording that data in a standard 3D file format. In other words, a ’screen grab’ or ‘view source’ operation for 3D data.”
15:30 OpenGL
Damn, look at the Unreal Tournament 2007 screenshots !!!
The Unreal Engine looks really beautiful I can’t wait to test it =)
10:39 OpenGL
From the OSG Ml :
http://aviatrix3d.j3d.org/using/basic_glsl.html
“Another issue to be very careful of is the
interaction between the basic geometry, the vertex
shader and any view frustum culling. Vertex shaders
can, and often do, shift the basic vertex of the
geometry. However, the view frustum culling has to
work with the raw data from before the vertex shader
has messed with it. For example, you start with a flat
grid of points and use the vertex shader to generate a
fractal landscape. The implicit bounding box used by
the input geometry is almost a flat plane. While that
implicit bounding box stays within the view frustum,
you’ll see everything correctly. However, the moment
that implicit bounds is entirely out of the view
frustum, the whole lot will be removed from further
processing, and the shader code will never get
executed. That is, your fractal terrain suddenly just
disappears for no apparent reason. To prevent this
from happening, make sure that you set explicit bounds
for your geometry that would represent the maximal
extents that the vertex shader is likely to perturb
the vertices to. In this way, nothing gets culled from
view while any of that volume intersects with the view
frustum.”
17:18 OpenGL
on the OSG ml, Jan Ciger writes :
“The VBOs are used by default, if the hardware supports them ( WRONG says Robert.. ) . So if you enable them by hand, it will most likely have no effect, because they were used already.
Moreover, VBO is not a magic bullet, aka “I enable VBOs and it will run 500fps faster.” It depends a lot on what kind of rendering are you doing. If you are just rendering a static mesh (not dynamically deformed), the fastest option is usually using display lists.
VBOs make sense if you are modifying the data (e.g. deforming the mesh). It is similar to using vertex arrays, but without having to upload the whole array each time. Thus, do not expect big gains on static data - such as your big sphere. VBOs could be even slower than display lists on such data because of the overhead.
You would get much larger performance difference if you were rendering e.g. human bodies with skinning where the mesh is deformed during each frame..
Regards,
Jan”
15:02 OpenGL
Interesting presentations at nvidia.com :
- An introduction to shaders and how to integrate them into your applications.
- Shaders in Your Toolchain : - COLLADA - FX Composer 2 - Softimage.
11:34 OpenGL
From 3D Labs Presentations :
GLSL Shading with OSG — zipped PDF (1.20 Mb) — 31 Jul 2005
Mike Weiblen described using the OpenGL Shading Language with OpenSceneGraph as part of the seminar entitled Advanced Rendering Techniques using OpenSceneGraph.
10:11 OpenGL
See this OpenGL Discussion :
Microsoft’s current plan for OpenGL on Windows Vista is to layer OpenGL over Direct3D in order to use OpenGL with a composited desktop to obtain the Aeroglass experience. If an OpenGL ICD is run - the desktop compositor will switch off - significantly degrading the user experience.
In practice this means for OpenGL under Aeroglass:
It would be technically straightforward to provide an OpenGL ICD within the full Aeroglass experience without compromising the stability or the security of the operating system. Layering OpenGL over Direct3D is a policy more than a technical decision.
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