Animated file format

I want to develop my own animated file format for opengl,using glDrawElements() functions. I have some questions : - I want to start from meshes in .3ds format. I convert them into opengl file to obtain the vertex-index-color-texcoord arrays. I espected to obtain different vertex arrays, as many as the number of the key-frames, but one only index - color and texcoord array, being the same object. On the contrary even the index arrays.. etc change from frame to frame. Am I wrong or is there anything wrong with the file converter I use? - Is it better to use the interpolation method or to increase the number of key frames to have a smooth animation. A part from the size of the file, which one is faster ? (pentium 3 1000, GeForce 2) - Does the glDrawElements() function automatically store the trasformed vertex ? Thanks in advance and regards to everybody Alberto