GLSL Texture Animation Blinking

Robert Osfield

2008-09-19 08:05:09 UTC

Hi Umit,

I wouldn't recommend using lots of separate textures. Personally I'd
pack the data into either a texture atlas or a Texture3D.

Robert.

Post by Ãmit Uzun
Hi All,
I am trying to create GLSL texture animation on terrain surface. To
simplify, I am using only 4 image and one of them white image to mix using
alpha value. The others are caustics textures. When I create animation some
frame blinking with dark screen as you see from VIDEO. I am using OSG-2.7 on
XP. What should I do to take smooth frames?
Another question, how should I send the images to the GLSL fragment shader?
I have to use 30 caustics texture in every LOD and I will create 4 LOD. So
how should I organize these 120 texture for making caustics animation? I
think using Uniforms for every texture isn't help me because of texture
units can't enough for all of them.
Best Regards.
Umit Uzun
-------------------------------Vertex-Shader-----------------------------------
void main()
{
gl_TexCoord[0] = gl_MultiTexCoord0;
gl_Position = ftransform();
}
-------------------------------Vertex-Shader-----------------------------------
-------------------------------Fragment-Shader-----------------------------------
uniform sampler2D Texture0;
uniform sampler2D Texture1;
uniform sampler2D Texture2;
uniform sampler2D Texture3;
uniform float timer;
//-------------------
void main()
{
vec4 texel0, texel1,texel2,texel3, resultColor;
//-------------------
texel0 = texture2D(Texture0, gl_TexCoord[0].st);
texel1 = texture2D(Texture1, gl_TexCoord[0].st);
texel2 = texture2D(Texture2, gl_TexCoord[0].st);
texel3 = texture2D(Texture3, gl_TexCoord[0].st);
//-------------------
if( timer < 1.0f )
{
resultColor = mix(texel0,texel1,0.5f);
}
else if( timer <= 2.0f)
{
resultColor = mix(texel0,texel1,0.5f);
}
else if(timer <= 3.0f)
{
resultColor = mix(texel0,texel2,0.5f);
}
else if(timer <= 4.0f)
{
resultColor = mix(texel0,texel3,0.5f);
}
gl_FragColor = resultColor;
}
-------------------------------Fragment-Shader-----------------------------------
---------------------------------OSG-Code-------------------------------------
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>
#include <osgDB/ReadFile>
#include <osg/Texture2D>
#include <osgGA/StateSetManipulator>
#include <osg/Program>
#include <osg/PolygonMode>
#include <math.h>
static float frameTime = 0.0f;
osg::Uniform* timer;
class UpdateStateCallback : public osg::NodeCallback
{
UpdateStateCallback() {}
virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
{
if(frameTime >= 4.0f) frameTime = 0.0f;
frameTime += 0.1f;
timer->set(frameTime);
traverse(node,nv);
}
};
int main()
{
osgViewer::Viewer viewer;
osg::ref_ptr<osg::Group> root (new osg::Group);
osg::ref_ptr<osg::Node> terrain = osgDB::readNodeFile("Terrain2.3ds");
osg::ref_ptr<osg::StateSet> stateset = (terrain->getOrCreateStateSet());
//Its shader objects
osg::ref_ptr<osg::Program> terrainProg (new osg::Program);
osg::ref_ptr<osg::Shader>
terrainvertexShader(osg::Shader::readShaderFile (osg::Shader::VERTEX,
"vertex.vert"));
osg::ref_ptr<osg::Shader> terrainfragShader(osg::Shader::readShaderFile
(osg::Shader::FRAGMENT, "fragment.frag"));
//Binding the box shaders to its program
terrainProg->addShader(terrainvertexShader.get());
terrainProg->addShader(terrainfragShader.get());
//Attaching the shader program to the node
stateset->setAttribute(terrainProg.get());
osg::ref_ptr<osg::Image> image0 (osgDB::readImageFile("white.bmp"));
osg::ref_ptr<osg::Texture2D> tex0 (new osg::Texture2D(image0.get()));
stateset->setTextureAttributeAndModes(0,tex0.get(),osg::StateAttribute::ON);
stateset->addUniform(new osg::Uniform("Texture0",0));
osg::ref_ptr<osg::Image> image1
(osgDB::readImageFile("caustics_deep_002.tga"));
osg::ref_ptr<osg::Texture2D> tex1 (new osg::Texture2D(image1.get()));
stateset->setTextureAttributeAndModes(1,tex1.get(),osg::StateAttribute::ON
);
stateset->addUniform(new osg::Uniform("Texture1",1));
osg::ref_ptr<osg::Image> image2
(osgDB::readImageFile("caustics_deep_003.tga"));
osg::ref_ptr<osg::Texture2D> tex2 (new osg::Texture2D(image2.get()));
stateset->setTextureAttributeAndModes(2,tex2.get(),osg::StateAttribute::ON
);
stateset->addUniform(new osg::Uniform("Texture2",2));
osg::ref_ptr<osg::Image> image3
(osgDB::readImageFile("caustics_deep_004.tga"));
osg::ref_ptr<osg::Texture2D> tex3 (new osg::Texture2D(image3.get()));
stateset->setTextureAttributeAndModes(3,tex3.get(),osg::StateAttribute::ON
);
stateset->addUniform(new osg::Uniform("Texture3",3));
stateset->addUniform(new osg::Uniform("timer",frameTime));
timer = stateset->getUniform("timer");
//Adding all the shape to the root node for rendering
root->addChild(terrain.get());
root->setUpdateCallback(new UpdateStateCallback());
// add the state manipulator to the viewer
viewer.addEventHandler( new
osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()) );
//Stats Event Handler s key
viewer.addEventHandler(new osgViewer::StatsHandler);
viewer.setSceneData( root.get() );
return (viewer.run());
}
---------------------------------OSG-Code-------------------------------------
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