3D free rotation of object

I have a 3D CAD file of a set of products. I want to create a viewe开发者_C百科r so that the user can freely rotate the object in 3D.

How would I best go about this?

1) I had thought about exporting a series of 360 degree images every 30 degrees around the image, but that would be around 360 images per product. Then right the code to handle the matrix that would be required to handle rotation of the object. Seems very excessive, but doable.

2) OpenGL - I have never done any 3d animation using this, though.

We are using LightWave 3D, if that helps.

I'd recommend going with the 3-D rendering route, even though it might require more upfront work than the multiple sliced images approach. It will provide much greater flexibility over the long run, and I think you'll be able to generate a more pleasing experience in the end (small application binary size, smoother rotation, etc.). Also, once you have the display code done, you'll be able to pull in arbitrary models to add on to the ones you started with, and make tweaks to those models more easily.

This question points out a number of ways that you might be able to import LightWave models into formats usable by an OpenGL ES application. It looks like you'll probably need to pass through Blender or another intermediary to accomplish this.

Once you have the model in a form that you can work with, you can build off of several open source 3-D rendering applications for the iPhone / iPad, such as my Molecules application. My application is built for displaying 3-D molecular structures, but people have modified it to support rendering other models for their own needs, so I know that's possible. I go into detail on how this application works in the video for the OpenGL ES session of my class on iTunes U.

OpenGL ES may seem intimidating at first, but it only took me three weeks of nights-and-weekends development to build the initial version of Molecules, and I had no real OpenGL experience before starting that project. There are many great resources out there now, so it's easier than ever to get started.