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murderv

OpenGL cgfx same shader, different objects

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hi, im trying to render a simple scene made of 2 meshes (3d grids) that the only difference between them is the texture and the color. for some reason the rendering is a mess. it seems to swap the textures and the lighting is different on one of the grids (the top one) i am using Java and opengl and using the CgGL to load my effect files, but that would be irrelevant imo on this matter. hope anyone can enlight me about this kinda problems. here's the code (functions are wrappers i made over the CgGL's, but you should be able to understand it)

  //
  // Draw bacvkground with light attenuation
  //
  CGpass pass;

  //
  // Draw diffuse+specular solid mesh
  //
  // CgGL.cgGetFirstPass( technique )
  pass = diffuseSpecularCG.getTechniqueFirstPass( "Technique_DiffuseAttenuation" );
  while( pass != null )
  {
    CgGL.cgSetPassState( pass );

    // if( param != null ) CgGL.cgGLSetTextureParameter( param, val );
    diffuseSpecularCG.setTextureParameter( "ColorSampler", bgTex.getId() );
    diffuseSpecularCG.setParameter4f( "lightPos", light.x, light.y, light.z, 1.0 );

    diffuseSpecularCG.setParameter3f( "lightDir", lightDir.x, lightDir.y, lightDir.z );
    diffuseSpecularCG.setParameter3f( "cameraPos", eye );
    diffuseSpecularCG.setParameter1f( "kC", kC );
    diffuseSpecularCG.setParameter1f( "kL", kL );
    diffuseSpecularCG.setParameter1f( "kQ", kQ );   

    gl.fill( 1 );
    //bgTex.enable();
    gl.rectTexCoord( 4, 4 );
    gl.texCoordOffset( (time*0.5)*.42, cos(time*0.4)*.3 );
    gl.pushMatrix();
    gl.translate( 0, 0, -50 );
    
    diffuseSpecularCG.setParameter4x4f( "WorldViewProjection", CgGL.CG_GL_MODELVIEW_PROJECTION_MATRIX, CgGL.CG_GL_MATRIX_IDENTITY );
    diffuseSpecularCG.setParameter4x4f( "World", CgGL.CG_GL_MODELVIEW_MATRIX, CgGL.CG_GL_MATRIX_INVERSE_TRANSPOSE );
    
    drawGrid();
    gl.popMatrix();

    CgGL.cgResetPassState( pass );
    pass = CgGL.cgGetNextPass( pass );
  }


  //
  // Draw diffuse+specular solid mesh
  //
  // CgGL.cgGetFirstPass( technique )
  pass = diffuseSpecularCG.getTechniqueFirstPass( "Technique_DiffuseAttenuation" );
  while( pass != null )
  {
    CgGL.cgSetPassState( pass );

    // if( param != null ) CgGL.cgGLSetTextureParameter( param, val );
    diffuseSpecularCG.setTextureParameter( "ColorSampler", bodyTex.getId() );

    diffuseSpecularCG.setParameter4f( "lightPos", light.x, light.y, light.z, 1.0 );

    diffuseSpecularCG.setParameter3f( "lightDir", lightDir.x, lightDir.y, lightDir.z );
    diffuseSpecularCG.setParameter3f( "cameraPos", eye );
    diffuseSpecularCG.setParameter1f( "kC", kC );
    diffuseSpecularCG.setParameter1f( "kL", kL );
    diffuseSpecularCG.setParameter1f( "kQ", kQ );   

    gl.fill( 1, 1, 0, .25 );
    //bgTex.enable();
    gl.rectTexCoord( 9, 4 ); // wrap texture coords
    gl.texCoordOffset( (time*0.5)*.42, sin(time*0.4)*.3 ); // move texture
    gl.pushMatrix();
    gl.translate( 0, 0, -35 );

    diffuseSpecularCG.setParameter4x4f( "WorldViewProjection", CgGL.CG_GL_MODELVIEW_PROJECTION_MATRIX, CgGL.CG_GL_MATRIX_IDENTITY );
    diffuseSpecularCG.setParameter4x4f( "World", CgGL.CG_GL_MODELVIEW_MATRIX, CgGL.CG_GL_MATRIX_INVERSE_TRANSPOSE );

    drawGrid();
    gl.popMatrix();

    CgGL.cgResetPassState( pass );
    pass = CgGL.cgGetNextPass( pass );
  }

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Hi murdev,
I've had the same problem using CgFx. The solution is that you must call

CgGL.cgSetPassState( pass );

AFTER you have set all the parameters, and right before the draw call.

So the code must be:


diffuseSpecularCG.setParameter4x4f( "World", CgGL.CG_GL_MODELVIEW_MATRIX, CgGL.CG_GL_MATRIX_INVERSE_TRANSPOSE );

CgGL.cgSetPassState( pass );

drawGrid();

gl.popMatrix();

My problem was that the matrixes and the textures were all messed up...

Hope it helps!

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One other thing, if I may.
For performance reasons, many switch to simple CgPrograms and custom RenderState, this because CgFx set ALL the states even to default value EVERYTIME you call CgSetPassState, so keep an eye on it and see if this solution can be better.
In this other way, you have to switch to programs (vertex and pixel) with handles, so the new render cycle become:


CgSetPassState

For (i = 0; i < meshwiththesameshader; i++)

diffuseSpecularCG.setTextureParameter( "ColorSampler", bgTex.getId() );

diffuseSpecularCG.setParameter4f( "lightPos", light.x, light.y, light.z, 1.0 );

...

cgUpdateProgramParameters(vertexProgramHandle)
cgUpdateProgramParameters(pixelProgramHandle)

DRAW


CgResetPassState


If you want and of you can, try those different solution and understand which one is best for you!

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Joren,

well i was trying to avoid using programs. i like the concept of FX files.
i just dont see the reason why is this so complicated.

first of all i've checked CgGL in java and there is no cgUpdateProgramParameters function which cancels out that option you just told me to try.

even if cgFX resets all states to default, what would that mean ?
by states (render/texture) i think of blending modes texture envmodes, matrices resets, etc

so if im using a simple phong lighting + attenuation shader and i want to call it twice or more times what is really the default changes that are happening that in the second call the light attenuation is not working at all.. actually the lighting is not working at all. the second call to render my quads (particles) just seems to render the particles in the correct place, the correct texture but they all are lit to the max, it seems it takes no lighting calculations. its just like glColor4f( 1, 1, 1, 1 );


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ok, here's something new i found out.

if i use glTranslate to render my shape the lighting does not work. it i render the shape at its position without glTranslate it works :|

1. it works, but i keep all my data as objectspace and use glTranslate for translations. and i also need to use glRotate.
i do alot of pushMatrix/popMatrix and gltranslate and glrotate.
what could be wrong here ???


2. weird thing is, the first shape i draw (background) uses a glTranslate to position it and the lighting works just fine. its just on the next calls that it screws lighting, still the rendering works fine. the shapes show up in place, they just aint lit'ed.


-----------------------------------
here's the none working code (AFTER background render that uses same shader):


gl.pushMatrix();
vgl.translate( fieldsLoc[0].x, fieldsLoc[0].y, fieldsLoc[0].z );
diffuseAttenuationCG.setTextureParameter( "ColorSampler", fieldTex.getId() );
diffuseAttenuationCG.setParameter4f( "lightPos", light.x, light.y, light.z, 1.0 );
diffuseAttenuationCG.setParameter1f( "kC", kC );
diffuseAttenuationCG.setParameter1f( "kL", kL );
diffuseAttenuationCG.setParameter1f( "kQ", kQ );
diffuseAttenuationCG.setParameter4x4f( "WorldViewProjection", CgGL.CG_GL_MODELVIEW_PROJECTION_MATRIX, CgGL.CG_GL_MATRIX_IDENTITY );
diffuseAttenuationCG.setParameter4x4f( "World", CgGL.CG_GL_MODELVIEW_MATRIX, CgGL.CG_GL_MATRIX_INVERSE_TRANSPOSE );
pass = diffuseAttenuationCG.getTechniqueFirstPass( "Technique_DiffuseAttenuation" );
CgGL.cgSetPassState( pass );

gl.quad( fieldsRadius[0] );

CgGL.cgResetPassState( pass );
gl.popMatrix();



--------------------------------------------
and here's the working code (AFTER background render that uses same shader):


diffuseAttenuationCG.setTextureParameter( "ColorSampler", fieldTex.getId() );
diffuseAttenuationCG.setParameter4f( "lightPos", light.x, light.y, light.z, 1.0 );
diffuseAttenuationCG.setParameter1f( "kC", kC );
diffuseAttenuationCG.setParameter1f( "kL", kL );
diffuseAttenuationCG.setParameter1f( "kQ", kQ );
diffuseAttenuationCG.setParameter4x4f( "WorldViewProjection", CgGL.CG_GL_MODELVIEW_PROJECTION_MATRIX, CgGL.CG_GL_MATRIX_IDENTITY );
diffuseAttenuationCG.setParameter4x4f( "World", CgGL.CG_GL_MODELVIEW_MATRIX, CgGL.CG_GL_MATRIX_INVERSE_TRANSPOSE );
pass = diffuseAttenuationCG.getTechniqueFirstPass( "Technique_DiffuseAttenuation" );
CgGL.cgSetPassState( pass );

// HERE IS THE DIFFERENCE. i pass the world space QUAD vertices instead of using glTranslate and passing object-space vertices.
gl.quad( fieldsLoc[0].x, fieldsLoc[0].y, fieldsLoc[0].z, fieldsRadius[0] );

CgGL.cgResetPassState( pass );

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after some trial and error i still havent got this thing to work.
i found out some things that seem weird for the code below:

vgl.setDepthWrite( true );
vgl.setAlphaBlend();

// Draw using opengl matrix states
for( int ti=0; ti<6; ti++ )
{
// Set parameters for used shader
diffuseAttenuationCG.setParameter3f( "cameraPos", eye.x, eye.y, eye.z );
diffuseAttenuationCG.setParameter4f( "lightPos", light.x, light.y, light.z, 1.0 );
diffuseAttenuationCG.setParameter1f( "kC", kC );
diffuseAttenuationCG.setParameter1f( "kL", kL );
diffuseAttenuationCG.setParameter1f( "kQ", kQ );
diffuseAttenuationCG.setTextureParameter( "ColorSampler", arirClock[ti].getId() );

vgl.pushMatrix();
vgl.translate( px, py, pz );
vgl.rotateZ( time*1*12*((3-ti)+1) );
diffuseAttenuationCG.setParameter4x4f( "worldViewProj", CgGL.CG_GL_MODELVIEW_PROJECTION_MATRIX, CgGL.CG_GL_MATRIX_IDENTITY );
diffuseAttenuationCG.setParameter4x4f( "matWorld", CgGL.CG_GL_MODELVIEW_MATRIX, CgGL.CG_GL_MATRIX_INVERSE_TRANSPOSE );

pass = diffuseAttenuationCG.getTechniqueFirstPass( "Technique_DiffuseAttenuation" );
CgGL.cgSetPassState( pass );
vgl.fill( 1 );
vgl.quad( fieldsRadius );

CgGL.cgResetPassState( pass );
vgl.popMatrix();
}



When i move the light to the position (0, 0, 0) all quads are lit equally even if the shader has an attenuation value.
the quads are moving side to side and the light direction looks ok, but it works exactly the same for all quads which is very weird as you can see in the picture.

jblitproblemon1.jpg


one thing i've also tested was not passing the light, which worked the same.. VERY WEIRD INDEED!

now what WORKS is not using opengl matrix translate/rotate and pass the position directly to the quad render.

for some reason it doesnt seem to take into account the matrix transformations, but the quads show on screen as you can see and they look ok.. just the lighting doesnt work as it was supposed to

anyone had this problem or have any idea what it can be ??

thanks

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