| Wednesday, October 7, 2009 |
  ASEToBin 1.0 release | 
Posted - 10/7/2009 4:48:43 AM | Finally, the long awaited ASEToBin 1.0 has been released !
ASEToBin is a tool that is part of the I-Novae engine ( Infinity's engine ). It allows contributors and artists to export their model from 3DS Max's .ASE file format and to visualize and prepare the 3D model for integration into the game.
This new release represents more or less 200 hours of work, and is filled with tons of new features, like new shaders with environmental lighting, skyboxes, a low-to-high-poly normal mapper, automatic loading/saving of parameters, etc..
ASEToBin Version 1.0 release, 06/10/2009:
http://www.fl-tw.com/Infinity/Docs/SDK/ASEToBin/ASEToBin_v1.0.zip
Changes from 0.9 to 1.0:
- rewrote "final" shader into GLSL; increase of 15% performance (on a Radeon 4890).
- fixed various problems with normal mapping: artifacts, symmetry, lack of coherency between bump and +Z normal aps, etc.. hopefully the last revision. Note that per-vertex interpolation of the tangent space can still lead to smoothing artifacts, but that should only happen in extreme cases (like the cube with 45° smoothed normals) that should be avoided by artists in the first place.
- removed anisotropic fx in the final shader and replaced it by a fresnel effect. Added a slider bar to control the strength of the fresnel reflection ("Fresnel").
- changed the names of the shaders in the rendering modes listbox to be more explicit on what they do.
- set the final shader (now "Full shading") to be the default shader selected when the program is launched.
- added a shader "Normal lighting" that shows the lighting coming from per-pixel bump/normal mapping.
- added support for detail texturing in "Full Shading" shader. The detail texture must be embedded in the alpha channel of the misc map.
- increased accuracy of specular lighting with using the real reflection vector instead of the old lower precision half vector.
- added support for relative paths.
- added support for paths to textures that are outside the model's directory. You can now "share" textures between different folders.
- added automatic saving and reloading of visual settings. ASEToBin stores those settings in an ascii XML file that is located next to the model's .bin file.
- ase2bin will not exit anymore when some textures could not be located on disk. Instead it will dump the name of the missing textures in the log file and use placeholders.
- fixed a crash bug when using the export option "merge all objects into a single one".
- ambient-occlusion generator now takes into account the interpolated vertex normals instead of the triangle face. This will make the AO map look better (non-facetted) on curved surfaces. Example:
Before 1.0: http://www.infinity-universe.com/Infinity/Docs/SDK/ASEToBin/ao_before.jpg
In 1.0: http://www.infinity-universe.com/Infinity/Docs/SDK/ASEToBin/ao_after.jpg
- added edge expansion to AO generator algorithm, this will help to hide dark edges on contours due to bilinear filtering of the AO map, and will also fix 1-pixel-sized black artifacts. It is *highly recommended* to re-generate all AO maps on models that were generated from previous version of ASEToBin, as the quality increase will be tremendous.
- automatic saving/loading of the camera position when loading/converting a model
- press and hold the 'X' key to zoom the camera (ICP style)
- press the 'R' key to reset the camera to the scene origin
- reduced the znear clipping plane distance. Should make it easier to check small objects.
- program now starts maximized
- added a wireframe checkbox, that can overlay wireframe in red on top of any existing shader mode.
- added a new shader "Vertex lighting" that only shows pure per-vertex lighting
- fixed a crash related to multi-threading when generating an AO map or a normal map while viewing a model at the same time.
- added a skybox dropdown that automatically lists sll skyboxes existing in the ASEToBin's Data/Textures sub-directories. To create your own skyboxes, create a folder in Data/textures (name doesn't matter), create a descr.txt file that will contain a short description of the skybox, then place your 6 cube map textures in this directory. They'll be automatically loaded and listed the next time ASEToBin is launched.
- the current skybox is now saved/reloaded automatically for each model
- added a default xml settings file for default ASEToBin settings when no model is loaded yet. This file is located at Data/settings.xml
- removed the annoying dialog box that pops up when an object has more than 64K vertices
- fixed a bug for the parameter LCol that only took the blue component into account for lighting
- added support for environment cube map lighting and reflections. Added a slider bar to change the strength of the environment lighting reflections ("EnvMap"). Added a slider bar to control the strength of the environment ambient color ("EnvAmb").
- added experimental support for a greeble editor. This editor allows to place greeble meshes on top of an object. The greeble is only displayed (and so only consumes cpu/video resources) when the camera gets close to it. This may allow kilometer-sized entities to look more complex than they are in reality.
- added experimental support for joypads/joysticks. They can now be used to move the camera in the scene. Note that there's no configuration file to customize joystick controls, and the default joystick is the one used. If your joystick doesn't work as expected, please report any problem on the forums.
- added a slider bar for self-illumination intensity ("Illum")
- added a slider bar for the diffuse lighting strength ("Diffuse")
- added a Capture Screenshot button
- added a new shader: checkerboard, to review UV mapping problems (distortions, resolution incoherency, etc..)
- added the number of objects in the scene in the window's title bar
- added a button that can list video memory usage for various resources (textures, buffers, shaders) in the viewer tab
- added a Show Light checkbox in the visualization tab. This will display a yellowish sphere in the 3D viewport in the direction the sun is.
- added new shaders to display individual texture maps of a model, without any effect or lighting (Diffuse Map, Specular Map, Normal Map, Ambient Map, Self-illumination Map, Misc Map, Detail Map)
- fixed numerous memory/resources leaks
- added a button in the visualization tab to unload (reset) the scene.
- added an experimental fix for people who don't have any OpenGL hardware acceleration due to a config problem.
- added a button in the visualization tab to reset the camera to the scene origin
- added a checkbox in the visualization tab to show an overlay grid. Each gray square of the grid represents an area of 100m x 100m. Each graduation on the X and Y axis are 10m. Finally, each light gray square is 1 Km.
- added a feature to generate ambient-occlusion in the alpha channel of a normal map when baking a low-poly to a high-poly mesh. Note: the settings in the "converter" tab are used, even if disabled, so be careful!
Note: Spectre's Phantom model is included as an example in the Examples/ directory !
Screenshots (click to enlarge):
| |
| Thursday, August 20, 2009 |
| Tip of the day: logarithmic zbuffer artifacts fix | |
Posted - 8/20/2009 11:37:35 AM | Logarithmic zbuffer artifacts fix
In cameni's Journal of Lethargic Programmers, I've been very interested by his idea about using a logarithmic zbuffer.
Unfortunately, his idea comes with a couple of very annoying artifacts, due to the linear interpolation of the logarithm (non-linear) based formula. It particularly shows on thin or huge triangles where one or more vertices fall off the edges of the screen. As cameni explains himself in his journal, basically for negative Z values, the triangles tend to pop in/out randomly.
It was suggested to keep a high tesselation of the scene to avoid the problem, or to use geometry shaders to automatically tesselate the geometry.
I'm proposing a solution that is much more simple and that works on pixel shaders 2.0+: simply generate the correct Z value at the pixel shader level.
In the vertex shader, just use an interpolator to pass the vertex position in clip space (GLSL) (here I'm using tex coord interpolator #6):
void main()
{
vec4 vertexPosClip = gl_ModelViewProjectionMatrix * gl_Vertex;
gl_Position = vertexPosClip;
gl_TexCoord[6] = vertexPosClip;
}
Then you override the depth value in the pixel shader:
void main()
{
gl_FragColor = ...
const float C = 1.0;
const float far = 1000000000.0;
const float offset = 1.0;
gl_FragDepth = (log(C * gl_TexCoord[6].z + offset) / log(C * far + offset));
}
Note that as cameni indicated before, the 1/log(C*far+1.0) can be optimized as a constant. You're only really paying the price for a mad and a log.
Quality-wise, I've found that solution to work perfectly: no artifacts at all. In fact, I went so far as testing a city with centimeter to meter details seen from thousands of kilometers away using a very very small field-of-view to simulate zooming. I'm amazed by the quality I got. It's almost magical. ZBuffer precision problems will become a thing of the past, even when using large scales such as needed for a planetary engine.
There's a performance hit due to the fact that fast-Z is disabled, but to be honnest in my tests I haven't seen a difference in the framerate. Plus, tesselating the scene more or using geometry shaders would very likely cost even more performance than that.
I've also found that to control the znear clipping and reduce/remove it, you simply have to adjust the "offset" constant in the code above. Cameni used a value of 1.0, but with a value of 2.0 in my setup scene, it moved the znear clipping to a few centimeters.
Results
Settings of the test:
- znear = 1.0 inch
- zfar = 39370.0 * 100000.0 inches = 100K kilometers
- camera is at 205 kilometers from the scene and uses a field-of-view of 0.01°
- zbuffer = 24 bits
Normal zbuffer:
http://www.infinity-universe.com/Infinity/Media/Misc/zbufflogoff.jpg
Logarithmic zbuffer:
http://www.infinity-universe.com/Infinity/Media/Misc/zbufflogon.jpg
Future works
Could that trick be used to increase precision of shadow maps ?
| |
| Wednesday, August 19, 2009 |
| Seamless filtering across faces of dynamic cube map | |
Posted - 8/19/2009 9:37:53 AM | Tip of the day
Anybody who tried to render to a dynamic cube map probably has encountered the problem of filtering across the cube faces. Current hardware does not support filtering across different cube faces AFAIK, as it treats each cube face as an independent 2D texture (so when filtering pixels on an edge, it doesn't take into account the texels of the adjacent faces).
There are various solutions for pre-processing static cube maps, but I've yet to find one for dynamic (renderable) cube maps.
While experimenting, I've found a trick that has come very handy and is very easy to implement. To render a dynamic cube map, one usually setups a perspective camera with a field-of-view of 90 degrees and an aspect ratio of 1.0. By wisely adjusting the field-of-view angle, rendering to the cube map will duplicate the edges and ensure that the texel colors match.
The formula assumes that texture sampling is done in the center of texels (ala OpenGL) with a 0.5 offset, so this formula may not work in DirectX.
The field-of-view angle should equal:
fov = 2.0 * atan(s / (s - 0.5))
where 's' is half the resolution of the cube (ex.: for a 512x512x6 cube, s = 256).
Note that it won't solve the mipmapping case, only bilinear filtering across edges.
Results:
Dynamic 8x8x6 cube without the trick:
http://www.infinity-universe.com/Infinity/Media/Misc/dyncube_seam1.jpg
Dynamic 8x8x6 cube with the trick:
http://www.infinity-universe.com/Infinity/Media/Misc/dyncube_seam2.jpg
| |
|
| S | M | T | W | T | F | S | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | | | | | |
OPTIONS
Track this Journal
ARCHIVES
October, 2009
August, 2009
July, 2009
May, 2009
April, 2009
March, 2009
February, 2009
January, 2009
November, 2008
October, 2008
July, 2008
June, 2008
May, 2008
April, 2008
March, 2008
January, 2008
December, 2007
November, 2007
October, 2007
September, 2007
August, 2007
July, 2007
June, 2007
May, 2007
April, 2007
March, 2007
February, 2007
January, 2007
December, 2006
November, 2006
October, 2006
September, 2006
August, 2006
July, 2006
June, 2006
May, 2006
April, 2006
March, 2006
February, 2006
January, 2006
December, 2005
November, 2005
October, 2005
September, 2005
August, 2005
July, 2005
June, 2005
May, 2005
April, 2005
March, 2005
February, 2005
January, 2005
December, 2004
October, 2004
September, 2004
August, 2004
|
