[osg-users] How to combine soft shadow mapping with normal mapping (and possibly other techs)?
Hi. I know OSG has built-in soft shadow mapping, but I'm not sure if it has normal mapping. I only know how to implement normal mapping in GLSL, but not how to combine built-in OSG soft shadow mapping with custom normal mapping shader. Please tell me how to do it. Thanks. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Problem with TBN matrix
Hello Peterakos,
Have you checked if the tangent space gives you correct results if
applied to lighting?
Also I don't understand what you need the tangent space for. Usually the
fragment's normal is what you already have in the normal-buffer, if
you doing some sort of deferred shading.
In this case you would write screenspace or viewspace normals to your
normal-buffer and simply use them in the SSAO pass.
Another issue that comes to mind is that there is no such thing as the
tangent space of a single fragment, so maybe explain to us, what the
tangent space is needed for in your opinion.
cheers
Sebastian
Hello.
I try to implement an ssao algorithm, but i cant figure out why the
grey artifacts appear (image 1).
Samples
---
Here i create the sample points that will be checked:
//assume hemisphere
float radius = 1.0f;
for (int i=0; i16; ++i) {
osg::Vec3f sample = osg::Vec3f(
getRandomFloat(-radius, radius),
getRandomFloat(-radius, radius),
getRandomFloat(0, radius)
);
sample.normalize();
uni-setElement(i,sample);
}
Fragment Shader
Here i create the tangent space based on fragment's normal (image 2):
vec3 normal = normalize( getFragNormal() * 2.0 - 1.0 );
vec3 temp_vec = vec3(normal.x, -normal.y, normal.z);
vec3 tangent = normalize(cross(temp_vec, normal));
vec3 bitangent = normalize(cross(normal, tangent));
mat3 tbn = mat3(tangent, bitangent, normal); //Do i have to transpose this ?
And here is the usage of tbn and sample:
vec4 sample_in_view_space = origin + vec4( tbn * sample_kernel[i] , 0);
where origin is the fragments world coordinates.
After that i project the sample back to window coordinates and i test
the depth value.
The first thing that comes to my mind is that i get grey pixels
because there are occluders for those pixels.
That shouldnt be happening, because the hemisphere is normal oriented
according to fragments normal.
Do i miss anything as fas as TBN matrix is concerned ?
Thank you for your time and sorry for the long post.
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[osg-users] qt rendering thread
Hi, Current state GraphicsWindowQt uses QTimer and function osgQt::setViewer for rendering traversal. It's clever, because Qt and osg events get correctly dispatched. But if fps drops, Qt Gui lags, mainly because some events (menu for example) will request redraw. I want to render scene in different thread, so it will not slow down my app when render slow frame. And maybe reset rendering if I for example move my scene. How to achieve that ? Thank you! Cheers, Filip -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=51046#51046 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Review of osgQt changes.
Hi, I am just learning about the changes to the OpenGL integration in Qt 5. The new way of dealing with OpenGL seems to be a lot less retarded than the QGLWidget way. You can simply create a QOpenGLContext object in the render thread and a QSurface object in the GUI thread and do context-makeCurrent(surface). No opengl calls are done implicitly by Qt. So maybe it would be wise to simply leave the nightmare that is Qt4/OpenGL integration behind us and start anew :) Cheers, Martin -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=51048#51048 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] How to combine soft shadow mapping with normal mapping (and possibly other techs)?
Hi Michael, First of all you should search the forum for questions regarding shadow mapping and custom shaders. The general answer is: Write your own vertex and fragment shaders and simply apply the shadow mapping as in the stock shaders by applying the shadow term to your lighting. Look into the source code of the shadow technique, usually there are in-code shader sources. hth Sebastian __ Hi. I know OSG has built-in soft shadow mapping, but I'm not sure if it has normal mapping. I only know how to implement normal mapping in GLSL, but not how to combine built-in OSG soft shadow mapping with custom normal mapping shader. Please tell me how to do it. Thanks. ___ 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
Re: [osg-users] Oddities when loading a FLT file
I had another thought on this, Chris. Set a breakpoint in the Multiswitch constructor and verify that the missing Multiswitch is being created under both circumstances. Assuming that test passes, set a breakpoint in the Multiswitch destructor, it should get hit when the missing Multiswitch is deleted. Then you can look at the call stack and find out why and how it is being removed. -Paul On 11/8/2012 7:55 PM, Chris Hanson wrote: I've encountered a strange behavior when loading a client-supplied FLT file and I haven't been able to drill down and find an explanation. I think I know what must be happening, but I can't find any mechanism to explain how. The customer has a TXP database which refers to a FLT model. The FLT model has a named MultiSwitch node, which controls some LightPointNodes. The symptom is that if the FLT file is loaded by itself (into osgViewer.exe for example) a NodeVisitor of ours is able to locate the MultiSwitch by name. If the FLT file is loaded via the DataBasePager from the TXP file, the FLT loads, but the visitor is unable to locate the MultiSwitch. Further investigation (adding debug code in a readfilecallback to save out a temporary .OSG file) reveals that somehow the MultiSwitch is not even in the resulting graph that gets produced from the FLT file. Converting the FLT file to OSG via osgconv, or a simple readNodeFile+writeNodeFile at the beginning of main() however produces an .OSG file that does contain the missing MultiSwitch. I've gone so far as to add this debug code at the beginning of main(), as well as in the readfilecallback that is invoked when the databasepager loads the FLT file: osgDB::ReaderWriter::ReadResult result = osgDB::Registry::instance()-readNodeImplementation(foo.flt,NULL); osgDB::writeNodeFile(*(result.getNode()), foo.osg); I use readNodeImplementation to ensure we're avoiding any callbacks. When execute from main(), this code produces a OSG file containing the MultiSwitch. When copy pasted to the readfilecallback, it produces a OSG file lacking the MultiSwitch. . I don't believe the osgUtil Optimizer is in play here, as the databasepager runs that after the load returns. I don't think any of the FLT loader options ( http://www.openscenegraph.org/projects/osg/wiki/Support/KnowledgeBase/OpenFlight )like preserveObject are affecting things, because I'm passing a NULL options pointer in both cases. What else could be different between these two cases that could lead to a different graph being produced from the same FLT file, and how do I unify this to one (correct) behavior? (I wouldn't think preserveObject or other FLT loader options would be optimizing out a MultiSwitch as redundant anyway, but perhaps it's misguided.) Please grant me some sanity. -- Chris 'Xenon' Hanson, omo sanza lettere. xe...@alphapixel.com http://www.alphapixel.com/ Training • Consulting • Contracting 3D • Scene Graphs (Open Scene Graph/OSG) • OpenGL 2 • OpenGL 3 • OpenGL 4 • GLSL • OpenGL ES 1 • OpenGL ES 2 • OpenCL Digital Imaging • GIS • GPS • Telemetry • Cryptography • Digital Audio • LIDAR • Kinect • Embedded • Mobile • iPhone/iPad/iOS • Android ___ 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
Re: [osg-users] Problem with TBN matrix
Hello. I use this method: http://www.john-chapman.net/content.php?id=8 for ssao pass. For each fragment i create a hemisphere of samples. This hemisphere is oriented based on fragment's normal, which means the samples have to be oriented based on normal too. The problem is that i cant be sure for correctness. If i use more samples, the grey artifacts tend to disappear. I also use blur for more smooth results. thnx. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Keyboard handler: SHIFT modifier doesn't work on Linux
robertosfield wrote: Could you try the osgkeyboard example Example works fine -- thanks for the tip! I've tracked the issue (in my code) to masking against osgGA::GUIEventAdapter::KEY_Shift_L instead of (like the example) osgGA::GUIEventAdapter::MODKEY_LEFT_SHIFT. Thank you very much for the quick response, Mike -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=51051#51051 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] how to use several texture one time?
i have a mesh and want to project several photo on the mesh . code is here:
osg::Switch *layer = new osg::Switch;
osg::Geode* leaf = 0;
if (!hasTexture){
leaf = createLeaf(points, numOfVert, tris,header.np);
layer-addChild(leaf);
}else{
osg::Group *group = new osg::Group;
for (unsigned int gr = 0; gr header.ngr; gr++){
/*for every group , load the different texture*/
osg::Texture2D* texture = 0L;
osg::ref_ptrosg::Image image;
if(osgDB::isAbsolutePath(groups[gr].texmap)){
image = osgDB::readImageFile(std::string(groups[gr].texmap));
}else{
std::string absoluteFile = osgDB::getFilePath(fileName)
+ std::string(/)
+ std::string(groups[gr].texmap);
image = osgDB::readImageFile(absoluteFile);
}
texture = new osg::Texture2D;
texture-setImage( image.get() );
if (texture-getImage()!=0L){
group-getOrCreateStateSet()-setTextureAttributeAndModes(gr,texture );
//set texture units
group-getOrCreateStateSet()-setTextureAttribute(gr, new
osg::TexEnv(osg::TexEnv::DECAL));
}
/*create group leaf*/
leaf = createLeaf(points, tris_t, groups[gr].poly_begin, groups[gr].poly_end,
gr);
group-addChild(leaf);
}
layer-addChild(group);
}
the problem is that just one texture unit works .
in case :
for (unsigned int gr = 0; gr header.ngr; gr++){ unit 0 works
for (unsigned int gr = 1; gr 2; gr++){ unit 1
works
then , how can i show the whole mesh with texture?
thanks in advance
Shawl___
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