vertices

Hello,

I am wondering how to render a cube without the diagonal cross section?

Did this somehow change recently? I have been able to do it before but it seems now that it comes standard with the diagonal cross section. I need to get rid of this for aesthetic reasons. How can I do this like as in the 1024 camera perspective example?

http://1024d.wordpress.com/2012/01/03/_1024_cameracorrection-qcplugin/#c...

Hi to all, I'm trying to extend my iniTree plugin with a custom plugin that outputs a structure with vertices position every frame, as suggested by gToledo. To try this kind of output I tried to modify my drawTest plugin so instead of render vertices it outputs vertices position.. but I cannot make it work properly. This is my approach:

• vertices positions are stored in a float vector

float   v[VSIZE][3];

• vertices positions are copied every frame in a NSArray (output_struct) made of NSArrays (currVertex) in this way:

   for(int x=0;x<numV;x++){
      [currVertex removeAllObjects];
      [currVertex addObject:[NSNumber numberWithFloat:v[x][0]]];
      [currVertex addObject:[NSNumber numberWithFloat:v[x][1]]];
      [currVertex addObject:[NSNumber numberWithFloat:v[x][2]]];
      [currVertex addObject:[NSNumber numberWithFloat:1.0]];
      [outputVertices addObject:currVertex];
   }
 
      //create output structure
   self.output_struct = [NSArray arrayWithArray:outputVertices];

It seems to output the same kind of result of a mesh importer (you can see it in outputs img), but for some reason my plugin output doesn't work. In the zip you can find xcode project, a composition example and a dae mesh to test it.

I think I don't build the structure in the correct way. For example, in the Apple developer guide I read that we must use NSDictionary to output a structure, but I can't use it in the correct way. Anyone knows the correct way to output a structure from a custom plugin?

Hi to all, I'm developing a plugin that allows you to render a set of vertices randomly distributed in space. I’d like to draw a huge amount of vertices at the same time: to do this I tried to use OpenGL Vertex Buffer Object (VBO), because I read that it allows vertex array data to be stored in high-performance graphics memory on the server side and promotes efficient data transfer.

This is my approach:
* Generate a new buffer object with glGenBuffersARB().
* Bind the buffer object with glBindBufferARB().
* Copy vertex data to the buffer object with glBufferDataARB().

so in my startExecution plugin function I wrote:

- (BOOL) startExecution:(id<QCPlugInContext>)context
{
   CGLContextObj cgl_ctx = [context CGLContextObj];
 
   glGenBuffersARB(1, &VBUFFERNAME);
   glBindBufferARB(GL_ARRAY_BUFFER, VBUFFERNAME);
//vcArray is defined as float vcArray[numV*3]
   glBufferDataARB(GL_ARRAY_BUFFER, sizeof(vcArray), vcArray, GL_DYNAMIC_DRAW_ARB);
   glVertexPointer(3, GL_FLOAT, 0, 0);
 
   return YES;
}

and in my execute plugin function I do this:
* Update vertices in vcArray using glBufferSubDataARB()
* Draw them using glDrawArrays()

- (BOOL) execute:(id<QCPlugInContext>)context atTime:(NSTimeInterval)time withArguments:(NSDictionary*)arguments
{
   CGLContextObj cgl_ctx = [context CGLContextObj];
 
   //update vcArray vertices
   updateVertices();
 
   glEnableClientState(GL_VERTEX_ARRAY);
   glBindBufferARB(GL_ARRAY_BUFFER, VBUFFERNAME);
   {
      glDrawArrays(GL_LINE_STRIP, 0, numV*3);
      [self calcVertices];
      glBufferSubDataARB(GL_ARRAY_BUFFER, 0, sizeof(vcArray), vcArray);
   }
   glDisableClientState(GL_VERTEX_ARRAY);
   glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
 
   return YES;
}

..the problem is that I can’t get noticeably performance improvements than the immediate mode rendering: they are the same! For example, using VBO I got 60 FPS with 2.500 vetices, 40 FPS with 5000 verices, and 10 FPS with 20.000 vertices.. and that are the same performance I got in immediate mode, using simple code like these:

glBegin(GL_LINE_STRIP);
for(x = 0; x<numV; x++){
   glVertex3f(v[x][0], v[x][1], v[x][2]);
}
glEnd();

..am I missing something in the VBO approach? Why I can’t get performance improvements?

Thank you, Luke