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Drawing to different models


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#1 sothro   Members   -  Reputation: 145

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Posted 23 March 2014 - 07:03 AM

Hi,

 

I'm currently trying to draw two different models, but when i draw 2 models where i put two different meshes in.

I only see the last mesh for the 2 models. It's using the same mesh for both of the models, so i think i'm overwriting something.

 

i'm using following code for the creation part:

    Model_3D *mo= new Model_3D();
    (*mo).CreateVertices("C:\\..\\Debug\\cube.obj");
    Model_3D *m= new Model_3D();
    (*m).CreateVertices("C:\\..\\Debug\\strange.obj");
    models->push_back(mo);
    m->TranslateX(-3);
    models->push_back(m);

    GLuint programId= glCreateProgram();

    for(GLuint var=0;var<models->size();var++)
    {
        models->at(var)->CreateObject();
        CreateObject(models->at(var),programId);
    }
GLuint BufferIdsTemp[3] = { 0 };

    model->SetShaderIdFragment(LoadShader("C:\\Users\\Sander\\Documents\\RTS idee\\idee\\engine\\GameEngine\\Debug\\SimpleShader.fragment.glsl", GL_FRAGMENT_SHADER));
    model->SetShaderIdVertex( LoadShader("C:\\Users\\Sander\\Documents\\RTS idee\\idee\\engine\\GameEngine\\Debug\\SimpleShader.vertex.glsl", GL_VERTEX_SHADER));

    model->SetShaderIdProgram(glCreateProgram());
    //ShaderIds[0] = glCreateProgram();
    ExitOnGLError("ERROR: Could not create the shader program");


    glAttachShader(model->GetShaderIdProgram(), model->GetShaderIdFragment());
    glAttachShader(model->GetShaderIdProgram(), model->GetShaderIdVertex());



    glLinkProgram(model->GetShaderIdProgram());
    ExitOnGLError("ERROR: Could not link the shader program");

    ModelMatrixUniformLocation = glGetUniformLocation(model->GetShaderIdProgram(), "ModelMatrix");
    ExitOnGLError("ERROR: Could not get the shader uniform locations for modelmatrix");
    ViewMatrixUniformLocation = glGetUniformLocation(model->GetShaderIdProgram(), "ViewMatrix");
    ExitOnGLError("ERROR: Could not get the shader uniform locations for viewmatrix");
    ProjectionMatrixUniformLocation = glGetUniformLocation(model->GetShaderIdProgram(), "ProjectionMatrix");
    ExitOnGLError("ERROR: Could not get the shader uniform locations for projectionMatrix");


    // bufferIds must be local array of gluints i think
    GLuint buffer=0;
    glGenVertexArrays(1, &BufferIdsTemp[0]);//&buffer);//
    //model->SetBufferId(BufferIdsTemp, 0);
    ExitOnGLError("ERROR: Could not generate the VAO");
    glBindVertexArray(BufferIdsTemp[0]);//model->GetBufferId(0));//
    ExitOnGLError("ERROR: Could not bind the VAO");

    //cube 1
    glEnableVertexAttribArray(0);
    glEnableVertexAttribArray(1);
    ExitOnGLError("ERROR: Could not enable vertex attributes");

    GLuint buffer2=0;

    glGenBuffers(2, &BufferIdsTemp[1]);//&buffer2 );//
    ExitOnGLError("ERROR: Could not generate the buffer objects");
    //model->SetBufferId(buffer, 1);

    int sizeVertex=sizeof(model->GetVertices().front());
    int vertexEllements=(model)->GetVertices().size();
    int sizeVertexes=sizeVertex*vertexEllements;
    glBindBuffer(GL_ARRAY_BUFFER,BufferIdsTemp[1]);// BufferIds[1]);//BufferIdsTemp
    //glBufferData(GL_ARRAY_BUFFER, sizeof(VERTICES), VERTICES, GL_STATIC_DRAW);
    glBufferData(GL_ARRAY_BUFFER, sizeVertexes, &model->GetVertices().front(), GL_STATIC_DRAW);

    ExitOnGLError("ERROR: Could not bind the VBO to the VAO");

    //glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, sizeof(VERTICES[0]), (GLvoid*)0);
    //glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, sizeof(VERTICES[0]), (GLvoid*)sizeof(VERTICES[0].Position));
    glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, sizeof(model->GetVertices().front()), (GLvoid*)0);
    glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, sizeof(model->GetVertices().front()), (GLvoid*)sizeof(model->GetVertices().front().Position));
    ExitOnGLError("ERROR: Could not set VAO attributes");


    int size=sizeof(model->GetIndices().front());
    int ellements=model->GetIndices().size();
    int sizeIndices=size*ellements;
    GLuint bufferId3=0;
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,BufferIdsTemp[2] );//bufferId3);
    //glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(INDICES), INDICES, GL_STATIC_DRAW);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeIndices,&model->GetIndices().front(), GL_STATIC_DRAW);
    //model->SetBufferId(bufferId3,2);//
    ExitOnGLError("ERROR: Could not bind the IBO to the VAO");

    model->SetBufferId(BufferIdsTemp);
    
    glBindVertexArray(0);

And the drawing part is done by this code:

void DrawObject(Model_3D* model)
{
    float CubeAngle;
    clock_t Now = clock();
    if (LastTime == 0)
        LastTime = Now;

    //CubeRotation += 45.0f * ((float)(Now - LastTime) / CLOCKS_PER_SEC);
    CubeAngle = DegreesToRadians(CubeRotation);
    LastTime = Now;
 
    glUseProgram( model->GetShaderIdProgram());
    ExitOnGLError("ERROR: Could not use the shader program");

    glUniformMatrix4fv(model->GetModelMatrixUniformLocation(), 1, GL_FALSE,model->GetMatrix().m);
    glUniformMatrix4fv(model->GetViewMatrixUniformLocation(), 1, GL_FALSE, camera->GetCamera().m );
    ExitOnGLError("ERROR: Could not set the shader uniforms");

    glBindVertexArray(model->GetBufferIds(0));//BufferIds[0]);
    ExitOnGLError("ERROR: Could not bind the VAO for drawing purposes");

    glDrawElements( GL_TRIANGLES, model->GetIndices().size(), GL_UNSIGNED_INT, (GLvoid*)0);
    ExitOnGLError("ERROR: Could not draw the cube");

    glBindVertexArray(0);
    glUseProgram(0);

}

I have one other problem and that is that i'm trying to put the code of createobject to my model class but when i try to draw the objects then i don't see anything. But this is a secondary problem the first thing i want to understand is to draw 2 different objects.

 

Can it be that i need a different shader for every object?

 

If someone can tell me how to fix that would be very helpfull.

Thank you for the help in advance.


Edited by sothro, 25 March 2014 - 11:41 AM.


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#2 sothro   Members   -  Reputation: 145

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Posted 16 April 2014 - 01:07 PM

I solved my problem, i needed to add following lines to my draw function:

    int sizeVertex=sizeof(GetVertices().front());
    int vertexEllements=GetVertices().size();
    int sizeVertexes=sizeVertex*vertexEllements;
    glBindBuffer(GL_ARRAY_BUFFER,GetBufferIds(1));// BufferIds[1]);//BufferIdsTemp

    glBufferData(GL_ARRAY_BUFFER, sizeVertexes, &GetVertices().front(), GL_STATIC_DRAW);





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