CODEWITHSUNDEEP
winformsopenglvisual-studio-2008antialiasing
Ander Biguri
Ander Biguri

Reputation: 35525

OpenGL aliasing?

I am working on win7 microsoft visual studio 08 with Forms. I just changed my graphic card and some kind of aliasing appears in my application.

img

It can be apreciated that the grey lines are kind of aliased, and also the reference system, that is almost invisible.

Any idea of how to solve this?

I'll post some part of the code just in case: 1: Paint function

private: void Paint(){



        int w = glControl1->Width;
        int h = glControl1->Height;


        float aspect_ratio = w / (float)h;
        Matrix4 perpective = Matrix4::CreatePerspectiveFieldOfView(MathHelper::PiOver4, aspect_ratio, 0.1f, 100000.0f);
        GL::MatrixMode(MatrixMode::Projection);
        GL::LoadMatrix(perpective);

        GL::MatrixMode(MatrixMode::Modelview);
        GL::LoadIdentity();
        GL::Viewport(0, 0, w, h);

        //Situacion de la camara en el espacio
        Matrix4 lookat = Matrix4::LookAt(100, 100, 100, 0, 0, 0, 0, 0, 1);
        GL::LoadMatrix(lookat);

        GL::Scale(this->zoom, this->zoom, this->zoom);


        GL::Rotate(xrot, 1.0f, 0.0f, 0.0f);
        GL::Rotate(yrot, 0.0f, 1.0f, 0.0f);
        GL::Clear(ClearBufferMask::ColorBufferBit | ClearBufferMask::DepthBufferBit);
           GL::ClearColor(Color::LightGray);



        Draw3Daxis();
        if (allowDraw){
            DrawSurface();
            }
        }

2: function that draws everything shown in the picture (it is just a bunch of GL::Vertex3)

System::Void Draw3Daxis(){
         OpcionesPlot* opciones;
         opciones=OpcionesPlot::Instance();
         int extra=2;
         int sqrnumber=10;

        //Planos en los ejes
        GL::Color3(Color::White);
        GL::Begin(BeginMode::Quads);
        if(opciones->draw3DXYaxis){
            GL::Vertex3(0,0,0);
            GL::Vertex3(LENGTH,0,0);
            GL::Vertex3(LENGTH,LENGTH,0);
            GL::Vertex3(0,LENGTH,0);
         }
         if(opciones->draw3DXZaxis){
             GL::Vertex3(0,0,0);
             GL::Vertex3(LENGTH,0,0);
             GL::Vertex3(LENGTH,0,LENGTH);
             GL::Vertex3(0,0,LENGTH);
         }
         if(opciones->draw3DYZaxis){
             GL::Vertex3(0,0,0);
             GL::Vertex3(0,LENGTH,0);
             GL::Vertex3(0,LENGTH,LENGTH);
             GL::Vertex3(0,0,LENGTH);
        }
         GL::End();


         // ejes XYZ
         GL::Color3(Color::Black);
         GL::Begin(BeginMode::Lines);
         if(opciones->draw3DXYaxis){
            GL::Vertex3(0,0,0);
            GL::Vertex3(LENGTH+extra,0,0);
            GL::Vertex3(0,0,0);
            GL::Vertex3(0,LENGTH+extra,0);
         }
         if(opciones->draw3DXZaxis){
             GL::Vertex3(0,0,0);
             GL::Vertex3(LENGTH+extra,0,0);
             GL::Vertex3(0,0,0);
             GL::Vertex3(0,0,LENGTH+extra);
         }
         if(opciones->draw3DYZaxis){
             GL::Vertex3(0,0,0);
             GL::Vertex3(0,LENGTH+extra,0);
             GL::Vertex3(0,0,0);
             GL::Vertex3(0,0,LENGTH+extra);
        }

         //--> lineas de los planos
         GL::Color3(Color::DarkGray);
         for(int i=1;i<=sqrnumber;i++){
             if(i==sqrnumber)
                 GL::Color3(Color::Black);
             if(opciones->draw3DXYaxis){
                 GL::Vertex3(LENGTH/sqrnumber*i,0,0);
                 GL::Vertex3(LENGTH/sqrnumber*i,LENGTH,0);
                 GL::Vertex3(0,LENGTH/sqrnumber*i,0);
                 GL::Vertex3(LENGTH,LENGTH/sqrnumber*i,0);
             }
             if(opciones->draw3DXZaxis){
                 GL::Vertex3(LENGTH/sqrnumber*i,0,0);
                 GL::Vertex3(LENGTH/sqrnumber*i,0,LENGTH);
                 GL::Vertex3(0,0,LENGTH/sqrnumber*i);
                 GL::Vertex3(LENGTH,0,LENGTH/sqrnumber*i);

             }
             if(opciones->draw3DYZaxis){
                 GL::Vertex3(0,0,LENGTH/sqrnumber*i);
                 GL::Vertex3(0,LENGTH,LENGTH/sqrnumber*i);
                 GL::Vertex3(0,LENGTH/sqrnumber*i,0);
                 GL::Vertex3(0,LENGTH/sqrnumber*i,LENGTH);
             }

         }
        GL::End();
        // triangulos para los ejes
        //----->cuadrado
        GL::Color3(Color::Black);
        GL::Begin(BeginMode::Quads);
        float quadside=0.7;
        if(opciones->draw3DXYaxis){
            GL::Vertex3((float)LENGTH+extra,quadside,quadside);
            GL::Vertex3((float)LENGTH+extra,-quadside,quadside);
            GL::Vertex3((float)LENGTH+extra,-quadside,-quadside);
            GL::Vertex3((float)LENGTH+extra,quadside,-quadside);

            GL::Vertex3(quadside,(float)LENGTH+extra,quadside);
            GL::Vertex3(-quadside,(float)LENGTH+extra,quadside);
            GL::Vertex3(-quadside,(float)LENGTH+extra,-quadside);
            GL::Vertex3(quadside,(float)LENGTH+extra,-quadside);


         }
         if(opciones->draw3DXZaxis){
            GL::Vertex3((float)LENGTH+extra,quadside,quadside);
            GL::Vertex3((float)LENGTH+extra,-quadside,quadside);
            GL::Vertex3((float)LENGTH+extra,-quadside,-quadside);
            GL::Vertex3((float)LENGTH+extra,quadside,-quadside);

            GL::Vertex3(quadside,quadside,(float)LENGTH+extra);
            GL::Vertex3(-quadside,quadside,(float)LENGTH+extra);
            GL::Vertex3(-quadside,-quadside,(float)LENGTH+extra);
            GL::Vertex3(quadside,-quadside,(float)LENGTH+extra);
         }
         if(opciones->draw3DYZaxis){
            GL::Vertex3(quadside,(float)LENGTH+extra,quadside);
            GL::Vertex3(-quadside,(float)LENGTH+extra,quadside);
            GL::Vertex3(-quadside,(float)LENGTH+extra,-quadside);
            GL::Vertex3(quadside,(float)LENGTH+extra,-quadside);

            GL::Vertex3(quadside,quadside,(float)LENGTH+extra);
            GL::Vertex3(-quadside,quadside,(float)LENGTH+extra);
            GL::Vertex3(-quadside,-quadside,(float)LENGTH+extra);
            GL::Vertex3(quadside,-quadside,(float)LENGTH+extra);

        }
        GL::End();


        // --> triangulos para hacer la punta
        GL::Begin(BeginMode::Triangles);
        if(opciones->draw3DXYaxis){
            GL::Vertex3((float)LENGTH+extra,quadside,quadside);
            GL::Vertex3((float)LENGTH+extra,-quadside,quadside);
            GL::Vertex3(LENGTH+extra+5,0,0);
            GL::Vertex3((float)LENGTH+extra,-quadside,quadside);
            GL::Vertex3((float)LENGTH+extra,-quadside,-quadside);
            GL::Vertex3(LENGTH+extra+5,0,0);
            GL::Vertex3((float)LENGTH+extra,-quadside,-quadside);
            GL::Vertex3((float)LENGTH+extra,quadside,-quadside);
            GL::Vertex3(LENGTH+extra+5,0,0);
            GL::Vertex3((float)LENGTH+extra,quadside,-quadside);
            GL::Vertex3((float)LENGTH+extra,quadside,quadside);
            GL::Vertex3(LENGTH+extra+5,0,0);

            GL::Vertex3(quadside,(float)LENGTH+extra,quadside);
            GL::Vertex3(-quadside,(float)LENGTH+extra,quadside);
            GL::Vertex3(0,LENGTH+extra+5,0);
            GL::Vertex3(-quadside,(float)LENGTH+extra,quadside);
            GL::Vertex3(-quadside,(float)LENGTH+extra,-quadside);
            GL::Vertex3(0,LENGTH+extra+5,0);
            GL::Vertex3(-quadside,(float)LENGTH+extra,-quadside);
            GL::Vertex3(quadside,(float)LENGTH+extra,-quadside);
            GL::Vertex3(0,LENGTH+extra+5,0);
            GL::Vertex3(quadside,(float)LENGTH+extra,-quadside);
            GL::Vertex3(quadside,(float)LENGTH+extra,quadside);
            GL::Vertex3(0,LENGTH+extra+5,0);

        }
        if(opciones->draw3DXZaxis){
            GL::Vertex3((float)LENGTH+extra,quadside,quadside);
            GL::Vertex3((float)LENGTH+extra,-quadside,quadside);
            GL::Vertex3(LENGTH+extra+5,0,0);
            GL::Vertex3((float)LENGTH+extra,-quadside,quadside);
            GL::Vertex3((float)LENGTH+extra,-quadside,-quadside);
            GL::Vertex3(LENGTH+extra+5,0,0);
            GL::Vertex3((float)LENGTH+extra,-quadside,-quadside);
            GL::Vertex3((float)LENGTH+extra,quadside,-quadside);
            GL::Vertex3(LENGTH+extra+5,0,0);
            GL::Vertex3((float)LENGTH+extra,quadside,-quadside);
            GL::Vertex3((float)LENGTH+extra,quadside,quadside);
            GL::Vertex3(LENGTH+extra+5,0,0);

            GL::Vertex3(quadside,quadside,(float)LENGTH+extra);
            GL::Vertex3(-quadside,quadside,(float)LENGTH+extra);
            GL::Vertex3(0,0,LENGTH+extra+5);
            GL::Vertex3(-quadside,quadside,(float)LENGTH+extra);
            GL::Vertex3(-quadside,-quadside,(float)LENGTH+extra);
            GL::Vertex3(0,0,LENGTH+extra+5);
            GL::Vertex3(-quadside,-quadside,(float)LENGTH+extra);
            GL::Vertex3(quadside,-quadside,(float)LENGTH+extra);
            GL::Vertex3(0,0,LENGTH+extra+5);
            GL::Vertex3(quadside,-quadside,(float)LENGTH+extra);
            GL::Vertex3(quadside,quadside,(float)LENGTH+extra);
            GL::Vertex3(0,0,LENGTH+extra+5);
         }
         if(opciones->draw3DYZaxis){
            GL::Vertex3(quadside,(float)LENGTH+extra,quadside);
            GL::Vertex3(-quadside,(float)LENGTH+extra,quadside);
            GL::Vertex3(0,LENGTH+extra+5,0);
            GL::Vertex3(-quadside,(float)LENGTH+extra,quadside);
            GL::Vertex3(-quadside,(float)LENGTH+extra,-quadside);
            GL::Vertex3(0,LENGTH+extra+5,0);
            GL::Vertex3(-quadside,(float)LENGTH+extra,-quadside);
            GL::Vertex3(quadside,(float)LENGTH+extra,-quadside);
            GL::Vertex3(0,LENGTH+extra+5,0);
            GL::Vertex3(quadside,(float)LENGTH+extra,-quadside);
            GL::Vertex3(quadside,(float)LENGTH+extra,quadside);
            GL::Vertex3(0,LENGTH+extra+5,0);

            GL::Vertex3(quadside,quadside,(float)LENGTH+extra);
            GL::Vertex3(-quadside,quadside,(float)LENGTH+extra);
            GL::Vertex3(0,0,LENGTH+extra+5);
            GL::Vertex3(-quadside,quadside,(float)LENGTH+extra);
            GL::Vertex3(-quadside,-quadside,(float)LENGTH+extra);
            GL::Vertex3(0,0,LENGTH+extra+5);
            GL::Vertex3(-quadside,-quadside,(float)LENGTH+extra);
            GL::Vertex3(quadside,-quadside,(float)LENGTH+extra);
            GL::Vertex3(0,0,LENGTH+extra+5);
            GL::Vertex3(quadside,-quadside,(float)LENGTH+extra);
            GL::Vertex3(quadside,quadside,(float)LENGTH+extra);
            GL::Vertex3(0,0,LENGTH+extra+5);

        }
        GL::End();
        Write3D(LENGTH,3,3,GLUT_BITMAP_9_BY_15,"X");
        Write3D(3,LENGTH,3,GLUT_BITMAP_9_BY_15,"Y");
        Write3D(3,3,LENGTH,GLUT_BITMAP_9_BY_15,"Z");
     }

Upvotes: 0

Views: 186

Answers (1)

Ani
Ani

Reputation: 10906

Try disabling depth testing before drawing each set of objects (reference planes first, axes second and then the reference grid).

It looks like your axes are Z-fighting the reference planes.

You have multiple options -

  1. Disable depth test when drawing the lines (not the planes). This will make sure that no z-fighting occurs.
  2. Keep depth testing on, but use glPolygonOffset when drawing the planes to offset them so that z-fighting does not happen at all.
  3. Use GL_LEQUAL (or whatever else) as the DepthFunc when drawing the planes, but use GL_EQUAL when drawing the lines. This should make things ok.

Upvotes: 2

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