glsl projective shader
Author
Im trying to use projective texturing with glsl but I have a problem.
Here is the screenshot
screenshot
As you can see there are black parts in the water they are over the edges of the water mesh.
I draw the water with vertex arrays and use triangle strips.
Here are the shaders.
//Vertex shader
varying vec4 ProjTexCoord;
void main()
{
mat4 MR;
gl_Position = ftransform();
gl_TexCoord[0] = gl_MultiTexCoord0;
MR=mat4(0.5,0.0,0.0,0.0,
0.0,0.5,0.0,0.0,
0.0,0.0,0.5,0.0,
0.5,0.5,0.5,1.0);
ProjTexCoord=(MR*gl_ModelViewProjectionMatrix)*gl_Vertex;
}
//fragment shader
uniform sampler2D tex0;
uniform sampler2D tex1;
varying vec4 ProjTexCoord;
void main()
{
vec4 color;
vec4 colProj;
color = texture2D(tex0, gl_TexCoord[0].xy);
colProj = texture2DProj(tex1, ProjTexCoord);
color = color * colProj;
gl_FragColor = color;
}
Author
When i put the reflection texture into texture unit 0 it works but if its in the 1.st unit it doesnt O_O.
I dont know why that happens.
I dont know why that happens.
Author
This is how i draw the water surface.
The RTT texture is in unit 0 and it works this way.
I active the shader before i draw the water :
drawShaders is the function above.
And these are the working shaders
But if I change the reflection from texture unit 0 to 1 and do all changes.I get the Image in screenshot.Black lines over the water surface other than that everything looks normal
[Edited by - phantom on November 6, 2005 7:34:10 PM]
The RTT texture is in unit 0 and it works this way.
glPushAttrib(GL_ENABLE_BIT); glVertexPointer(3,GL_FLOAT,0,m_pVertices); //glClientActiveTextureARB(GL_TEXTURE0_ARB); //glEnableClientState(GL_TEXTURE_COORD_ARRAY); //glTexCoordPointer(2,GL_FLOAT,0,m_pTexCoords); glClientActiveTextureARB(GL_TEXTURE1_ARB); glEnableClientState(GL_TEXTURE_COORD_ARRAY); glTexCoordPointer(2,GL_FLOAT,0,m_pTexCoords); //glDisableClientState(GL_TEXTURE_COORD_ARRAY); glDisableClientState(GL_NORMAL_ARRAY); //If we are over the water surface draw the water with projective texturing if(pCamera->getPosition().y>m_vPosition.y){ if(m_bDrawReflection){ glActiveTextureARB(GL_TEXTURE1_ARB); glEnable(GL_TEXTURE_2D); } glDisable(GL_LIGHTING); glActiveTextureARB(GL_TEXTURE1_ARB); glBindTexture(GL_TEXTURE_2D,m_iTextureName[(int)m_fCurrentTexture]); if(m_bDrawReflection){ glActiveTextureARB(GL_TEXTURE0_ARB); glEnable(GL_TEXTURE_2D); glBindTexture(GL_TEXTURE_2D,m_iRTextureName); } GLfloat remapMatrix[] = {0.5,0.0,0.0,0.0, 0.0,0.5,0.0,0.0, 0.0,0.0,0.5,0.0, 0.5,0.5,0.5,1.0}; glActiveTextureARB(GL_TEXTURE0_ARB); float Mproj[16],Mview[16]; glGetFloatv(GL_MODELVIEW_MATRIX,Mview); glGetFloatv(GL_PROJECTION_MATRIX,Mproj); glMatrixMode(GL_TEXTURE); { glLoadMatrixf(remapMatrix); glMultMatrixf(Mproj); glMultMatrixf(Mview); } glMatrixMode(GL_MODELVIEW); int count = m_iSize<<1; for(int i=0;i<m_iSize-1;i++) glDrawElements(GL_TRIANGLE_STRIP,count,GL_UNSIGNED_INT,&m_pIndices[(i*(m_iSize))<<1]); glMatrixMode(GL_TEXTURE); glLoadIdentity(); glMatrixMode(GL_MODELVIEW); glActiveTextureARB(GL_TEXTURE0_ARB);I active the shader before i draw the water :
m_PerPixel.use(ST_TRUE);//set shader texm_PerPixel.setInt(m_PerPixel.getVariable("tex0"),1);m_PerPixel.setInt(m_PerPixel.getVariable("tex1"),0);if(m_pWater)//m_pWater->draw(pCamera); m_pWater->drawShaders(pCamera);m_PerPixel.use(ST_FALSE);drawShaders is the function above.
And these are the working shaders
varying vec4 ProjTexCoord;void main(){ gl_Position = ftransform(); gl_TexCoord[1] = gl_MultiTexCoord1; ProjTexCoord = gl_TextureMatrix[0] * gl_Vertex; gl_FrontColor = vec4(1.0,1.0,1.0,1.0);}uniform sampler2D tex0;uniform sampler2D tex1;varying vec4 ProjTexCoord;const vec4 ambient = vec4(0.13), boost = vec4(1.06);void main(){ vec4 color = texture2D(tex0, gl_TexCoord[1].st); vec4 reflectionValue = texture2DProj(tex1, ProjTexCoord); gl_FragColor = boost * color * reflectionValue + ambient; }But if I change the reflection from texture unit 0 to 1 and do all changes.I get the Image in screenshot.Black lines over the water surface other than that everything looks normal
[Edited by - phantom on November 6, 2005 7:34:10 PM]
Author
Thnx for the formatting :P
Hmmm does calling texture2d() affect the other texture2dProj() in the fragment shader??I guess it shouldn't but yesterday when I commented it out the output was different.Maybe it was just my dead eyes I dunno...
Hmmm does calling texture2d() affect the other texture2dProj() in the fragment shader??I guess it shouldn't but yesterday when I commented it out the output was different.Maybe it was just my dead eyes I dunno...
Author
Ok not it works in texture unit 1 too but I had to remove my varying variable for that and use the gl_TexCoord[1] like this
Instead of gl_TexCoord[1] if I use ProjTexCoord it has those black artifacts in the screen shot O_O
varying vec4 ProjTexCoord;void main(){ gl_Position = ftransform(); gl_TexCoord[0] = gl_MultiTexCoord0; gl_TexCoord[1] = gl_TextureMatrix[1] * gl_Vertex; //ProjTexCoord = gl_TextureMatrix[1] * gl_Vertex;; gl_FrontColor = vec4(1.0,1.0,1.0,1.0);}uniform sampler2D base;uniform sampler2D reflection;varying vec4 ProjTexCoord;const vec4 ambient = vec4(0.13), boost = vec4(1.06);void main(){ vec4 color = vec4(texture2D(base, gl_TexCoord[0].st)); vec4 reflectionValue = vec4(texture2DProj(reflection, gl_TexCoord[1])); gl_FragColor = boost * reflectionValue + ambient; }Instead of gl_TexCoord[1] if I use ProjTexCoord it has those black artifacts in the screen shot O_O
Author
Hi Again :|
I want to disturb the reflections in the fragment shader by using another texture.
Here are the shaders :
And here is how it looks like :(
Screen Shot
If a remove the *20.0 then the black artifacts go away but the reflections is very calm.Im sure color is between 0.0-1.0.But if I add too much to dist.x the reflections get black artifacts.
Any help?
I want to disturb the reflections in the fragment shader by using another texture.
Here are the shaders :
varying vec4 ProjTexCoord;void main(){ gl_Position = ftransform(); gl_TexCoord[1] = gl_TextureMatrix[1] * gl_Vertex; ProjTexCoord = gl_TextureMatrix[1] * gl_Vertex; gl_TexCoord[0] = gl_MultiTexCoord0; gl_FrontColor = gl_Color;}varying vec4 ProjTexCoord;uniform sampler2D base;uniform sampler2D reflection;const vec4 ambient = vec4(0.13), boost = vec4(1.06);void main(){ vec4 color = vec4(texture2D(base, gl_TexCoord[0].st)); vec4 dist = vec4(0.0,0.0,0.0,0.0); dist.x = color.x * 20.0 + gl_TexCoord[1].s; dist.y = gl_TexCoord[1].t; dist.z = color.z * 20.0 +gl_TexCoord[1].r; dist.w = gl_TexCoord[1].q; //vec4 reflectionValue = vec4(texture2DProj(reflection, gl_TexCoord[1])); vec4 reflectionValue = vec4(texture2DProj(reflection, dist)); gl_FragColor = boost * reflectionValue + ambient; gl_FragColor.a = gl_Color.a;}And here is how it looks like :(
Screen Shot
If a remove the *20.0 then the black artifacts go away but the reflections is very calm.Im sure color is between 0.0-1.0.But if I add too much to dist.x the reflections get black artifacts.
Any help?
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