Here is a more informed email of what I'm trying to accomplish:
We have some old code that inherits from the ShadowMapTechnique to do most of
it's work which is based on the fixed-function pipeline. It uses the shadow
map's camera for projection of textures (among other things) and we are
redesigning it so that the base class is independent of the shadow map class.
I thought I had everything working when I gutted out this function in the
ViewData override function called addShadowReceivingTexGen():
_texgen->setMode(osg::TexGen::EYE_LINEAR);
// compute the matrix which takes a vertex from view coords into tex coords
_texgen->setPlanesFromMatrix(
mClampCallback->getLastProjection() *
osg::Matrix::translate(1.0, 1.0, 1.0) *
osg::Matrix::scale(0.5f, 0.5f, 0.5f));
osg::RefMatrix * refMatrix = new osg::RefMatrix
(_camera->getInverseViewMatrix() * *_cv->getModelViewMatrix());
_cv->getRenderStage()->getPositionalStateContainer()->
addPositionedTextureAttribute
(*_shadowTextureUnitPtr, refMatrix, _texgen.get());
This is evidently stored in OpenGL's built-in variables because it's used in
the vertex shader like this:
{
gl_TexCoord[1].s = dot(ecPosition, gl_EyePlaneS[1]);
gl_TexCoord[1].t = dot(ecPosition, gl_EyePlaneT[1]);
gl_TexCoord[1].p = dot(ecPosition, gl_EyePlaneR[1]);
gl_TexCoord[1].q = dot(ecPosition, gl_EyePlaneQ[1]);
}
My new solution for the addShadowReceivingTexGen() is a simple
updateTextureCoordinates() function:
mTexGenMatrix = mCamera->getViewMatrix() *mCamera->getProjectionMatrix() *
osg::Matrixd::translate(osg::Vec3d(1.0, 1.0, 1.0)) *
osg::Matrixd::scale(0.5, 0.5, 0.5);
And in the new vertex shader, I do this:
TexCoords[0] = TexGenMatrix0 * gl_Vertex;
Which goes from modelspace all the way to clip space. This works on simple
objects created at the origin in modelspace, but it does NOT work with an
entire world with large terrain.
I'd like to continue NOT using the gl_EyePlaneSTRQ and just doing a regular
transformation. However, going back to the old code for any clues is leading
me nowhere. I traced the 'addPositionedTextureAttribute' to this:
virtual void addPositionedTextureAttribute(unsigned int textureUnit,
osg::RefMatrix* matrix,const osg::StateAttribute* attr)
{
_texAttrListMap[textureUnit].push_back(AttrMatrixPair(attr,matrix));
}
.. but I'm not sure what it's doing here. The attr is the texgen object but
that's used to store a matrix. So what does the vertex shader 'see' from this
function?
I apologize for the long and drawn out email but I've been thinking on this for
a few hours now and am really new to OpenGL and not sure what some of this code
is trying to do.
Thanks,
-M
----------------------------------------
Marlin Rowley
Software Engineer, Staff
[cid:image002.jpg@01D39374.DEC5A2E0]
Missiles and Fire Control
972-603-1931 (office)
214-926-0622 (mobile)
marlin.r.row...@lmco.com<mailto:marlin.r.row...@lmco.com>
From: osg-users [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf
Of Rowley, Marlin R (US)
Sent: Wednesday, May 2, 2018 12:05 PM
To: OpenSceneGraph Users <osg-users@lists.openscenegraph.org>
Subject: EXTERNAL: [osg-users] Getting the main camera.
Is there a way to get a pointer to the main rendering camera without passing
the Viewer around through classes and functions?
Thanks,
-M
----------------------------------------
Marlin Rowley
Software Engineer, Staff
[cid:image002.jpg@01D39374.DEC5A2E0]
Missiles and Fire Control
972-603-1931 (office)
214-926-0622 (mobile)
marlin.r.row...@lmco.com<mailto:marlin.r.row...@lmco.com>
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