OpenGLES2 iOS: What's the best streaming vertex animation for dynamic terrain?

I am writing an application that creates a 640 * 480 dynamic landscape (changes every frame). Each terrain is stored in a raw data file that represents a string of float values. So far, I could read files sequentially in memory and dynamically create a grid based on the height values ​​of each frame (and the frame rate is actually reasonable), but I max out at about 20 frames before my application exits without error or stack footprint.

I suspect I am approaching this in the wrong way. How do I pass this data so that I can't keep every frame in memory?

Here is a section from my data class that contains a collection of landscapes:

- (void)addModelWithID:(int)modelID;
{
    NSString* resourcePath  = [[NSBundle mainBundle] resourcePath];
    NSString* fileName      = [NSString stringWithFormat:@"depth_%i.raw", modelID];
    NSString* fullPath = [resourcePath stringByAppendingPathComponent:fileName];

    NSData *myData = [NSData dataWithContentsOfFile:fullPath];
    if (!myData)
      return;

    const float *data = [myData bytes];

    int meshWidth               = 640;
    int meshHeight              = 480;

    Model *kModel = [[Model alloc] init];

    int indicesPtr  = 0;
    int depthPtr = 2;

    for (int y=0;y<meshHeight;y++)    // Loop through y pixels
        {
            for (int x=0;x<meshWidth;x++)   // Loop through x pixels
            {
                // Set up vertex positions
                int index  = y*meshWidth+x;
                float xpos = ((float)x/(float)(meshWidth-1)) - 0.5f;
                float ypos = ((float)y/(float)(meshHeight-1)) - 0.5f;
                float zpos = (float)data[index];

                kModel.vertices1[index*3+0] = xpos;
                kModel.vertices1[index*3+1] = ypos;
                kModel.vertices1[index*3+2] = zpos;

                // Create a new index based on whether the current line is even or odd (flipped horizontally if odd)
                int _index = (y%2==0) ? index : (y*meshWidth) + ((meshWidth-1)-x); 

                //Create the first index
                kModel.indices[indicesPtr++] = _index;

                // Create the second index
                if ((x<meshWidth-1) || (x==meshWidth-1 && y==meshHeight-2))
                    kModel.indices[indicesPtr++] = _index+meshWidth;
            }
        }
    }

    // Add the model to the data object
    [Models addObject:kModel];
    [kModel release];
}

      

        
        
        
      

    

And my drawing code (each frame I call a different terrain, hopefully up to 500 or so, but I maximize at ~ 20:

{
    ...
        Model *kModel = [kData.kinectModels objectAtIndex:sequenceCurrentFrame];

        glVertexAttribPointer(vertexHandle, 3, GL_FLOAT, GL_FALSE, 0, (const GLvoid*)kModel.vertices1);

        glEnableVertexAttribArray(vertexHandle);

        glUniformMatrix4fv(mvpMatrixHandle, 1, GL_FALSE, (const GLfloat*)&modelViewProjection.data[0]);
        glDrawElements(GL_TRIANGLE_STRIP, kModel.numIndices, GL_UNSIGNED_SHORT, (const GLvoid*)kModel.indices);
    ...
}

      

        
        
        
      

    

Thanks a million for your help,

Josh