atached vertex shader not compiled

romulo

Hello!

I´m trying to implement a directional light per vertex to simulate the OpenGL light and this error appears to me:

Attached vertex shader is not compiled.

But the strange is that when i compile, but changing this line: color = diffuse + specular + ambient; into this: color = vec4(1.0,0.0,0.0,1.0); actually works! But the problem is that the shader log is not point me what is wrong, and i couldn´t figure why!

This is the full vertex shader:

varying vec4 color;

//Light variables
uniform vec3 positionLight,ambientLight,diffuseLight,specularLight;

//Light Model
uniform vec3 lightModel;

//Material variables
uniform vec3 frontMaterialDiffuse,frontMaterialAmbient,
frontMaterialSpecular;
uniform float frontMaterialShininess;

vec3 getHalfVector(vec3 lightDir)
{
    vec3 v,l;
    v = vec3(gl_ModelViewMatrix * gl_Vertex);
    vec3 view = normalize(-v);
    l = normalize(lightDir - v);
    return normalize( l + view );
}
vec3 getDiffuse(vec3 N, float NdotL)
{
    vec3 diff = (diffuseLight * frontMaterialDiffuse);
    diff *= NdotL;
    return diff;
}
vec3 getAmbient(vec3 N, float NdotL)
{
    vec3 ambient = frontMaterialAmbient * ambientLight;
    vec3 globalAmbient = lightModel * ambientLight;
    return ambient + globalAmbient;
}
vec3 getSpecular(vec3 N, vec3 H,float NdotHV)
{
    vec3 spec = specularLight * frontMaterialSpecular;
    spec *=  pow(NdotHV,frontMaterialShininess);
    return spec;
}
void main()
{
    vec4 diffuse, ambient, specular = vec4(0.0);
    vec3 normal, lightDir, halfVector;
    float NdotL,NdotHV;

    normal = normalize(gl_NormalMatrix * gl_Normal);
    lightDir = normalize(vec3(positionLight));
    halfVector = getHalfVector(lightDir);

    NdotL = max(dot(normal, lightDir), 0.0);
    NdotHV = max(dot(normal,normalize(halfVector)),0.0);

    if (NdotL > 0.0)
    {
        diffuse = getDiffuse(normal,NdotL);
        specular =  getSpecular(normal,halfVector,NdotHV);
    }
    ambient = getAmbient(normal,NdotL);
   // color =  vec4(1.0,0.0,0.0,1.0);
    color =  diffuse + specular + ambient;

    gl_Position = ftransform();

}

this is the fragment shader:

        varying vec4 color;
        void main()
        {
            gl_FragColor = color;
        }

Any help will be appreciated, thanks!

amnon

Try adding: diffuse = vec4(0.0);

Also try using the variables that are used in Processing, see: https://processing.org/tutorials/pshader/

romulo

Thanks for the answer! In this line i already initialize all vec4 variables

vec4 diffuse, ambient, specular = vec4(0.0);

About the Processing, i can only use glsl also, i can not use built-in variables like gl_lightSource[] or gl_materials!

codeanticode

Processing shaders don't use any built-in lighting or matrix math variables from the older GL fixed-pipeline. Processing defines its own uniforms to store lighting parameters. Take a look at the Light Shaders section in the PShader tutorial

romulo

Thanks. As i said i cannot use Processing, only glsl.