Hi Kenzo.
I think you are misinterpreting the last argument to the textureLod,
which is an offset IIRC.
I use the following to sample the last level (which is 1 px and gives
you exactly the average):
exp(texture2DLod(LuminanceSampler, vec2(0.5,0.5), 1000.0));
cheers
Sebastian
Hi,
I've managed to generate my mipmap via the hardware. But I'm guessing I don't
have the good mipmap as the result of my tone mapping is unstable. The screen
is brighter in a jerky manner for some position of the camera.
As below, how to create my mipmap:
Code:
osg::ref_ptr<osg::Texture2D> tex2D =
dynamic_cast<osg::Texture2D*>(logAveragedLumTexture.get());
tex2D->setNumMipmapLevels(9);
tex2D->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
tex2D->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR_MIPMAP_LINEAR);
Then I'm retrieving the values of the smallest mipmap (2x2), by accessing to
the LOD level 9 as my texture is 512 by 512 as the beginning:
Code:
// get last mipmap level as 2x2 texture
vec4 lastMipmapLevel;
lastMipmapLevel.x = textureLod(logAveragedLumTexture, vec2(0.25, 0.25), 9.0).r;
lastMipmapLevel.y = textureLod(logAveragedLumTexture, vec2(0.75, 0.25), 9.0).r;
lastMipmapLevel.z = textureLod(logAveragedLumTexture, vec2(0.25, 0.75), 9.0).r;
lastMipmapLevel.w = textureLod(logAveragedLumTexture, vec2(0.75, 0.75), 9.0).r;
I'm not sure about the way to access to my mipmap. I've tried other texture
coordinates but the results is still unstable.
------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=50295#50295
_______________________________________________
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
_______________________________________________
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
