Databases
StackOverflow2013
Postsdbo
POOpenGL lines not colored
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POOpenGL lines not colored
    primarykey
    data
    text
    <p>I'm working in OpenGL, with VBOs, and I have a set of three lines (along the X, Y and Z axes - think Czech hedgehog). The lines are grey by default, but I want them bright red so I can see them better. Unfortunately, though I added color information as vertex data, the lines still appear grey. I'm probably missing something basic, but I can't see it. Here is how I create the VBO:</p> <pre><code>//Position data sf::Vector3&lt;float&gt; Top = sf::Vector3&lt;float&gt;(0.0, 1.0, 0.0); sf::Vector3&lt;float&gt; Front = sf::Vector3&lt;float&gt;(0.0, 0.0, -1.0); sf::Vector3&lt;float&gt; Right = sf::Vector3&lt;float&gt;(1.0, 0.0, 0.0); sf::Vector3&lt;float&gt; Back = sf::Vector3&lt;float&gt;(0.0, 0.0, 1.0); sf::Vector3&lt;float&gt; Left = sf::Vector3&lt;float&gt;(-1.0, 0.0, 0.0); sf::Vector3&lt;float&gt; Bottom = sf::Vector3&lt;float&gt;(0.0, -1.0, 0.0); //Color data //Just to be clear, I also tried with 255.0, although I'm rather certain OpenGL //does its colors on a 0-1 scale. sf::Vector3&lt;float&gt; Color = sf::Vector3&lt;float&gt;(1.0, 0.0, 0.0); //Create vector std::vector&lt;float&gt; LineArray; //Top LineArray.push_back(Top.x); LineArray.push_back(Top.y); LineArray.push_back(Top.z); LineArray.push_back(Color.x); LineArray.push_back(Color.y); LineArray.push_back(Color.z); //Bottom LineArray.push_back(Bottom.x); LineArray.push_back(Bottom.y); LineArray.push_back(Bottom.z); LineArray.push_back(Color.x); LineArray.push_back(Color.y); LineArray.push_back(Color.z); //Front LineArray.push_back(Front.x); LineArray.push_back(Front.y); LineArray.push_back(Front.z); LineArray.push_back(Color.x); LineArray.push_back(Color.y); LineArray.push_back(Color.z); //Back LineArray.push_back(Back.x); LineArray.push_back(Back.y); LineArray.push_back(Back.z); LineArray.push_back(Color.x); LineArray.push_back(Color.y); LineArray.push_back(Color.z); //Right LineArray.push_back(Right.x); LineArray.push_back(Right.y); LineArray.push_back(Right.z); LineArray.push_back(Color.x); LineArray.push_back(Color.y); LineArray.push_back(Color.z); //Left LineArray.push_back(Left.x); LineArray.push_back(Left.y); LineArray.push_back(Left.z); LineArray.push_back(Color.x); LineArray.push_back(Color.y); LineArray.push_back(Color.z); //Create buffer glGenBuffers(1, &amp;m_Buffer); glBindBuffer(GL_ARRAY_BUFFER, m_Buffer); int SizeInBytes = LineArray.size() * 6 * sizeof(float); glBufferData(GL_ARRAY_BUFFER, SizeInBytes, NULL, GL_STATIC_DRAW); //Upload buffer data glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(float) * LineArray.size(), &amp;LineArray[0]); </code></pre> <p>And this is how I display it every tick:</p> <pre><code>glPushMatrix(); //Translate glTranslatef(m_Position.x, m_Position.y, m_Position.z); //Rotate glMultMatrixf(m_RotationMatrix); //Bind buffers for vertex and color arrays glBindBuffer(GL_ARRAY_BUFFER, m_Buffer); glEnableClientState(GL_VERTEX_ARRAY); glVertexPointer(3, GL_FLOAT, 6 * sizeof(float), 0); glEnableClientState(GL_COLOR_ARRAY); glColorPointer(3, GL_FLOAT, 6 * sizeof(float), (void*)12); //Draw glDrawArrays(GL_LINES, 0, 36); glDisableClientState(GL_VERTEX_ARRAY); glDisableClientState(GL_COLOR_ARRAY); //Unbind the buffers glBindBuffer(GL_ARRAY_BUFFER, 0); glPopMatrix(); </code></pre> <p>I've never used GL_COLOR_ARRAY before, but I based the code off of successful use of GL_NORMAL_ARRAY. Can someone point out what's wrong?</p> <p>EDIT: On the offchance that I'm setting up my basic OpenGL parameters wrong (lighting in particular), here are those:</p> <pre><code>m_AmbientLight = {0.5f, 0.5f, 0.5f, 1.0f}; m_DiffuseLight = {1.0f, 1.0f, 1.0f, 1.0f}; m_LightPos = {8.0f, -16.0f, 8.0f, 0.0f}; //Smooth Shading glShadeModel(GL_SMOOTH); // Set color and depth clear value glClearDepth(1.f); //Color here is in RGB, converted to a 0-1 scale. glClearColor(0.3f, 0.3f, 0.3f, 1.f); // Enable Z-buffer read and write glEnable(GL_DEPTH_TEST); glDepthMask(GL_TRUE); /// ///LIGHTING /// //Set up lighting. //This activates the ambient light. glLightfv(GL_LIGHT0, GL_AMBIENT, m_AmbientLight); //This activates the diffuse light. glLightfv(GL_LIGHT1, GL_DIFFUSE, m_DiffuseLight); //This sets the position of the diffuse light. glLightfv(GL_LIGHT1, GL_POSITION, m_LightPos); //This enables the light. glEnable(GL_LIGHT0); glEnable(GL_LIGHT1); //Enables all lighting...? glEnable(GL_LIGHTING); glEnable(GL_COLOR_MATERIAL); //glEnable(GL_NORMALIZE); // Setup a perspective projection glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(60.f, 1.33f, 0.1f, 512.f); </code></pre> <p>EDIT 2: Having established that glColor3f() also doesn't have any effect, I wonder if my shaders are the problem:</p> <p>Vert shader:</p> <pre><code>void main() { vec3 normal, lightDir; vec4 diffuse; float NdotL; normal = normalize(gl_NormalMatrix * gl_Normal); lightDir = normalize(vec3(gl_LightSource[0].position)); NdotL = max(dot(normal, lightDir), 0.0); diffuse = gl_FrontMaterial.diffuse * gl_LightSource[0].diffuse; gl_FrontColor = NdotL * diffuse; gl_Position = ftransform(); } </code></pre> <p>Frag shader:</p> <pre><code>void main() { gl_FragColor = gl_Color; } </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USGarrickW
    1. USGarrickW
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POOpenGL lines not colored
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POOpenGL lines not colored
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POOpenGL lines not colored
      1. This table or related slice is empty.
      1. VTUpMod
    1. COFor what it's worth, that looks right to me. Maybe the error is elsewhere. You don't have texturing enabled by any chance do you?
      singulars
      1. POOpenGL lines not colored
      1. USTim
    2. CONo texture, but lighting. Maybe that's the problem?
      singulars
      1. POOpenGL lines not colored
      1. USGarrickW
    3. COIf you want to use the same color for all your lines, you could just use `glColor3f` instead.
      singulars
      1. POOpenGL lines not colored
      1. USfintelia
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload