Shader doesn't write anything for picking by id

Question

I am trying to implement picking by an int id, but it looks like my shader doesn't write anything, althought I can read the clear color properly.

vs, I skipped completely any matrix for debugging:

#version 330

#include semantic.glsl

layout (location = POSITION) in vec3 position;

uniform Transform0
{
    mat4 view;
    mat4 proj;
    mat4 viewProj;
};

uniform Transform1
{
    mat4[TRANSFORM1_SIZE] models;
};

uniform Parameters
{
    // x = mesh baseVertex
    // y = selected
    // z = active
    // w = id
    ivec4[INDICES_SIZE] params;
};

out Block
{
    flat int id;
} outBlock;

int getIndex()
{
    int iBegin = 0;
    int iEnd = params.length() - 1;

    int l = iBegin;
    int r = iEnd;

    int i = 0; 

    if(params.length > 1)
    {
        do 
        {
            i = int(((l + r) / 2.0f));

            if (l == (r - 1)) 
                if (l == 0 && gl_VertexID <= params[l].x || gl_VertexID <= params[l].x && gl_VertexID > params[l - 1].x)
                    return l;
                else if(gl_VertexID > params[l].x && gl_VertexID <= params[r].x)
                    return r;
                else 
                    return 0;
            else if (gl_VertexID == params[i].x) 
                return i;
            else if (gl_VertexID < params[i].x) 
                r = i;
            else if (gl_VertexID > params[i].x)
                l = i;
        } while (l < r);
    }    
    return 0;    
}

void main() 
{
    int index = getIndex();

    mat4 model = models[index];

    //gl_Position = proj * (view * (model * vec4(position, 1)));

    gl_Position = vec4(4.0 * float(gl_VertexID % 2) - 1.0, 4.0 * float(gl_VertexID / 2) - 1.0, 0.0, 1.0);

    outBlock.id = params[index].w;
}

fs, hardcoded value for the moment, output is 0 (FRAG_COLOR), tried also 1 but nothing:

#version 330

#include semantic.glsl

// Outgoing final color.
layout (location = FRAG_COLOR) out int outputColor;

in Block
{
    flat int id;
} inBlock;

void main() 
{    
    //outputColor = inBlock.id;
    outputColor = 9;
}

Init phase, I have one fbo, called RESOLVE, with 3 attachements, one depth, one float color on 0 and one integer for picking on 1. Fbo is complete:

gl3.glBindTexture(GL_TEXTURE_2D, textureName.get(Texture.RESOLVE_ID));
gl3.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
gl3.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
gl3.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
gl3.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
gl3.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
gl3.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
gl3.glTexImage2D(GL_TEXTURE_2D, 0, GL_R32I, EC.viewer.size.x, EC.viewer.size.y, 0, GL_RED_INTEGER, GL_INT, null);

gl3.glGenFramebuffers(Framebuffer.MAX - (samples == 1 ? 1 : 0), framebufferName);

gl3.glBindFramebuffer(GL_FRAMEBUFFER, framebufferName.get(Framebuffer.RESOLVE));
gl3.glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, textureName.get(Texture.RESOLVE_DEPTH), 0);
gl3.glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, textureName.get(Texture.RESOLVE_COLOR), 0);
gl3.glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, textureName.get(Texture.RESOLVE_ID), 0);

if (gl3.glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
    System.err.println("incomplete");
    return false;
}

and render & reading, added also glFlush, glFinish and glPixelStorei but nothing:

gl3.glBindFramebuffer(GL_FRAMEBUFFER, framebufferName.get(Framebuffer.RESOLVE));
gl3.glDrawBuffer(GL_COLOR_ATTACHMENT1);
gl3.glClearBufferiv(GL_COLOR, 0, clearId.put(0, 0)); // we care clearing only red

gl3.glBindVertexArray(EC.meshManager.vertexArrayName.get(0));

gl3.glEnable(GL_DEPTH_TEST);

gl3.glUseProgram(program.name);

gl3.glDrawElements(GL_TRIANGLES, EC_Gl3MeshManager.ELEMENT_OPAQUE_COUNT, GL_UNSIGNED_INT, 0);

gl3.glDisable(GL_DEPTH_TEST);

gl3.glReadBuffer(GL_COLOR_ATTACHMENT1);

glm.vec._2.i.Vec2i window = new glm.vec._2.i.Vec2i(
            EC.inputListener.mousePressed.getX(),
            EC.viewer.size.y - EC.inputListener.mousePressed.getY() - 1);
System.out.println("window (" + window.x + ", " + window.y + ")");

gl3.glFlush();
gl3.glFinish();
gl3.glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

//  Get the red coordinate reading the pixel click from the color 1 buffer, we can use the clearId buffer        
gl3.glReadPixels(window.x, window.y, 1, 1, GL_RED_INTEGER, GL_INT, clearId);
gl3.glReadBuffer(GL_COLOR_ATTACHMENT0);

As I said, if I clear with 10, I read 10, so that is working, the only problematic thing is my shader..

Can you spot the error, guys?

Edit: trying to debug, I am checking the attachment type on color 1

gl3.glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1,
        GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE, clearId);
System.out.println("GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE: " + clearId.get(0));
gl3.glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1,
        GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME, clearId);
System.out.println("GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME: " + clearId.get(0)+", tex: "+textureName.get(Texture.RESOLVE_ID));

I get:

GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE: 5890
GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME: 14, tex: 14

5890 is GL_TEXTURE, name looks correct

tried to use glFramebufferTexture2D, but I still get GL_TEXTURE type instead GL_TEXTURE_2D

Edit 2: trying to read the depth component, is always 0

I've had unhappy experiences writing pick IDs to multiple colour attachments on MacOS X, and on Linux with Intel integrated graphics. (Worked fine on nvidia.) Does the pick ID get written if the pick attachment is COLOR0? — Hugh Fisher, Aug 04 '16 at 10:08
Unfortunately it didn't get written neither in COLOR0, the depth test enabled was the problem — elect, Aug 04 '16 at 13:04

elect · Accepted Answer · 2016-08-04T14:39:09.717

1

Shame on me, the problem was the depth test, since I forgot to clean the buffer it was never passing

edited Aug 04 '16 at 14:39

answered Aug 04 '16 at 13:02

elect

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Shader doesn't write anything for picking by id

1 Answers1