WaveFront OBJ converted from LightWave taking forever to render on iPhone

Question

I'm working on a project where I need to render a 3D human body on an iOS device. The 3D object was built in Adobe LightWave and is 7.4MB. I opened it in Blender and exported it as OBJ/MTL pair which are 5.5MB and 4KB, respectively. Using Jeff LaMarche's Wavefront Loader (linked below) as a starting point to figure out OpenGL ES and get check out performance and whatnot, I stuck the object in there (in place of an OBJ/MTL pair he'd been using) and ran it in the simulator. Of course, crash on startup, so I decided to performSelectorInBackground it. A half hour later, it's still loading.

I'm just guessing that the file is way too detailed to draw with any kind of performance expectation on a device with a 600MHz processor. Is there a way to lower the quality these files somewhat easily? Or, if performance issues have arisen with this particular loader, could somebody enlighten me?

Thanks, Will

http://iphonedevelopment.blogspot.com/2009/03/wavefront-obj-loader-open-sourced-to.html

Answer 1

Will,

I don't know if I can solve your problem, but I may be able to point you in the right direction. I did a project for a client loading a 3D model exported from Blender using the SIO2 3D engine.

Anyway, at that time, I had trouble with the 3D engine taking a long time to load the model. I found that reducing the number of polygons was very important - if it is a high quality model, you most certainly will need to do so.

Blender has a function for this - polygon reduce or something like that. Blender should also report to you how many polygons and surfaces are in use, so if it's more than, say, 20,000, you're likely in for performance issues.