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• Hello guys,

How do I know? Why does wavefront not show for me?
I already checked I have non errors yet.

And my download (mega.nz) should it is original but I tried no success...
- Add blend source and png file here I have tried tried,.....

PS: Why is our community not active? I wait very longer. Stop to lie me!
Thanks !

• I wasn't sure if this would be the right place for a topic like this so sorry if it isn't.
I'm currently working on a project for Uni using FreeGLUT to make a simple solar system simulation. I've got to the point where I've implemented all the planets and have used a Scene Graph to link them all together. The issue I'm having with now though is basically the planets and moons orbit correctly at their own orbit speeds.
I'm not really experienced with using matrices for stuff like this so It's likely why I can't figure out how exactly to get it working. This is where I'm applying the transformation matrices, as well as pushing and popping them. This is within the Render function that every planet including the sun and moons will have and run.
if (tag != "Sun") { glRotatef(orbitAngle, orbitRotation.X, orbitRotation.Y, orbitRotation.Z); } glPushMatrix(); glTranslatef(position.X, position.Y, position.Z); glRotatef(rotationAngle, rotation.X, rotation.Y, rotation.Z); glScalef(scale.X, scale.Y, scale.Z); glDrawElements(GL_TRIANGLES, mesh->indiceCount, GL_UNSIGNED_SHORT, mesh->indices); if (tag != "Sun") { glPopMatrix(); } The "If(tag != "Sun")" parts are my attempts are getting the planets to orbit correctly though it likely isn't the way I'm meant to be doing it. So I was wondering if someone would be able to help me? As I really don't have an idea on what I would do to get it working. Using the if statement is truthfully the closest I've got to it working but there are still weird effects like the planets orbiting faster then they should depending on the number of planets actually be updated/rendered.

• Hello everyone,
I have problem with texture

• Hello everyone
For @80bserver8 nice job - I have found Google search. How did you port from Javascript WebGL to C# OpenTK.?
I have been searched Google but it shows f***ing Unity 3D. I really want know how do I understand I want start with OpenTK But I want know where is porting of Javascript and C#?

Thanks!
• By mike44
Hi
I draw in a OpenGL framebuffer. All is fine but it eats FPS (frames per second), hence I wonder if I could execute the framebuffer drawing only every 5-10th loop or so?
Many thanks

# OpenGL rendering hemi-sphere using opengl

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I'm trying to render a hemisphere in opengl, the problem that the hemisphere isn't rendered at all, only part of it. I initialize it, then at each frame I draw it using the following code. I'm trying to use a VBO for drawing it.

 void Jellyfish::Init_HemiSphere(const float radius, const int segments ) { m_iSegements = segments; m_fVerts= new float[(segments+1)*2*3]; m_fNormals= new float[(segments+1)*2*3]; m_fTexCoords = new float[(segments+1)*2*2]; for( int j = 0; j < segments / 2; j++ ) { float theta1 = j * 2 * 3.14159f / segments - ( 3.14159f ); float theta2 = (j + 1) * 2 * 3.14159f / segments - ( 3.14159f ); for( int i = 0; i <= segments; i++ ) { Vec3f e, p; float theta3 = i * 2 * 3.14159f / segments; e.x = math<float>::cos( theta1 ) * math<float>::cos( theta3 ); e.y = math<float>::sin( theta1 ); e.z = math<float>::cos( theta1 ) * math<float>::sin( theta3 ); p = e * radius; m_fNormals[i*3*2+0] = e.x; m_fNormals[i*3*2+1] = e.y; m_fNormals[i*3*2+2] = e.z; m_fTexCoords[i*2*2+0] = 0.999f - i / (float)segments; m_fTexCoords[i*2*2+1] = 0.999f - 2 * j / (float)segments; m_fVerts[i*3*2+0] = p.x; m_fVerts[i*3*2+1] = p.y; m_fVerts[i*3*2+2] = p.z; e.x = math<float>::cos( theta2 ) * math<float>::cos( theta3 ); e.y = math<float>::sin( theta2 ); e.z = math<float>::cos( theta2 ) * math<float>::sin( theta3 ); p = e * radius; m_fNormals[i*3*2+3] = e.x; m_fNormals[i*3*2+4] = e.y; m_fNormals[i*3*2+5] = e.z; m_fTexCoords[i*2*2+2] = 0.999f - i / (float)segments; m_fTexCoords[i*2*2+3] = 0.999f - 2 * ( j + 1 ) / (float)segments; m_fVerts[i*3*2+3] = p.x; m_fVerts[i*3*2+4] = p.y; m_fVerts[i*3*2+5] = p.z; } } glGenBuffers(3,&SVboId[0]); //Vertex glBindBuffer(GL_ARRAY_BUFFER,SVboId[0]); glBufferData(GL_ARRAY_BUFFER,sizeof(m_fVerts), m_fVerts,GL_DYNAMIC_DRAW); //Normal glBindBuffer(GL_ARRAY_BUFFER,SVboId[1]); glBufferData(GL_ARRAY_BUFFER,sizeof(m_fNormals), m_fNormals,GL_DYNAMIC_DRAW); //Textures glBindBuffer(GL_ARRAY_BUFFER,SVboId[2]); glBufferData(GL_ARRAY_BUFFER,sizeof(m_fTexCoords), m_fTexCoords,GL_DYNAMIC_DRAW); } void Jellyfish::drawHemiSphere( ) { glEnableClientState( GL_VERTEX_ARRAY ); glBindBuffer(GL_ARRAY_BUFFER,SVboId[0]); glVertexPointer( 3, GL_FLOAT, 0, 0 ); for( int j = 0; j < m_iSegements / 2; j++ ) { glDrawArrays( GL_TRIANGLE_STRIP, 0, (m_iSegements + 1)*2 ); } glDisableClientState( GL_VERTEX_ARRAY ); glDisableClientState( GL_TEXTURE_COORD_ARRAY ); glDisableClientState( GL_NORMAL_ARRAY ); } 

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Post a picture. I dont' get this:
for( int j = 0; j < m_iSegements / 2; j++ ) {
glDrawArrays( GL_TRIANGLE_STRIP, 0, (m_iSegements + 1)*2 );
}

You have a local variable j that is never used. Therefore you are drawing the same thing over and over again. Not to mention it always starts at 0. So if all your segments of the sphere are unconnected, then your loop would try to draw 0-100 verts, 0-200 verts, 0-300.
Probably want:
glDrawArrays(GL_TRIANGLE_STRIP, j*number_of_verts_insegment, number_of_verts_insegment); draw 0 to 100, 100 to 200, 200 to 300