Some more iPhone benchmarks and tests with everybody’s favorite difficult to pronounce 3d rendering framework!

Thumb mode and floating point:  Just don’t

Ok, first, I was an idiot before and somehow was still compiling in thumb mode. I know not to do that!

Somehow the setting was removed but I guess the default is ON even with it missing or something.  After adding it by hand it the math-heavy md2 anim rendering test went from 31 fps to 60+ fps.

I think the mistake came from editing the build configuration by clicking on the project settings instead of the “build target” settings, so I’m going to check both from now on to be safe.

Irrlicht and Quake 3 style .bsp demo

Irrlicht's .bsp map demo on iPhone using pvrtc4 textures with mipmaps and player collision enabled

I was expecting Irrlicht to do some kind of wicked optimizations when rendering a .bsp map.  Nope, it does nothing special.  You CAN load it into an octree but if OCTTREE_USE_HARDWARE is defined it renders the whole mesh anyway. (?!!?)   If that flag isn’t defined, it does render less primitives but without using VBO’s so it’s way slower anyway.

This forum thread may be of interest about that.

Collision detection would be a better candidate for a software octree but after playing with createOctTreeTriangleSelector with different settings I never saw even one fps of difference.  Strange, I would have expected it to noticeably help.

(this section was updated Dec 2nd after Tonic pointed out that you can use VBO’s with Octrees…)

Adding iPhone controls

As you can see in the screenshot above I’ve added a basic wolf3d control scheme to get around.

I use my own engine to handle the GUI overlay/handling (it draws after Irrlicht is done)  and just have it controlling Irrlicht’s FPSControlComponent.

I use camera->setTarget() to look up and down, and I fake UP/DOWN/LEFT/RIGHT key movement by sending pDevice->postEventFromUser() messages.  This works ok but bites because it’s not proportional or 360 degree so I’ll need to modify FPSControlComponent or just do my own movement stuff if I want to do it right.

Do using compressed textures help the FPS on the iPhone?

Short answer, a little.

I added CImageLoaderRTTEX to Irrlicht so it could load my own texture format.  It’s sort of a container that houses multiple formats including pvrct4, pvrct2, 4444 rgba, 565 rgb, etc.  It does extra stuff that normal .pvr’s don’t, like remember the original image size before padding or stretching.

I also modified the b3d and .bsp loader to look for textures with my .rttex file extension first.

Some rough numbers with the quake style .bsp map collision disabled:

• Map test with raw 32 bit textures with mipmap chain: 26 fps
• Map test with pvrtc4 format textures with mipmap chain: 28 fps

So yeah, tiny difference.

However, keep in mind there are also other good reasons to use pvrtc:

• Fast loading even when zlib’ed.  Especially compared to decompressing a .jpg
• Use a hell of a lot less texture memory

On the down side, the visual artifacts can look pretty bad so you still need some raw formats in your toolbox for specific images like GUI.

Do using mipmaps help speed on the iPhone?

I didn’t notice a difference.  Using mipmaps look better though, although I need to adjust the lod bias a bit so it doesn’t pop up so bad…

Tip: The iPhone requires a full mipmap chain to work, so don’t try to get tricky and only include a few of them.

For your enjoyment here is what  happens when your texture processing utility has a bug in its mipmap generation.  (The festive blue, pink, and green colors shouldn’t be there…)

Putting it all together, our own level

I’ve got to say, the king of the 3dsmax exporters for Irrlicht is B3D Pipeline.

I know, you’re thinking “Uh… b3d, that Blitz3d format?  Why not use collada or .x or something?” All I can say is this is the exporter that actually worked right for me when trying to get the lightmaps working.

So here is a low poly house in 3dsmax.  I’ve applied a light source and got it looking how I want.  Then I use max’s render to texture feature to make a single alpha lightmap.

The (old) iPhone has two texture units and this will be the second one, controlling where shadows appear, the same way the .bsp map example works.

After exporting it pops into the game engine fully lightmapped and ready to go with a single line of code.

After adding a skybox and a simplified collision mesh it still gets nearly 60 fps, not bad.  Too bad a game needs more than one house.  Hmm, my fov looks a bit extreme.

So being between projects means I get to play around with random technology!

For some upcoming secret projects I’ve setup Flite TTS and Irrlicht as plugins in my iPhone engine to test out.

Flite

It’s a text to speech thingie that lets you make the iPhone talk.   It’s uh… well, I actually don’t really have a problem with it except I’m having a hard time controlling pitch and inflection.  Does anybody know of a better library?  Here’s a sample I made of Flite using the Kal 16kz voice. (Flite 1.3)

First, I’m sorry about the content of the audio.   Second, there is a problem where raising the pitch for the (loosely) female voice causes clipping.  Maybe I shouldn’t be using “Kal” for that.

Irrlicht

This is a solid 3D engine that has been around forever but truly became appetizing after it went with the zlib license.

My tests on the iPhone have been a bit underwhelming, check these screenshots to see the FPS.

Sydney.md2 from irrlicht media. Disabling frame interpolation gave 45 fps.

Skinned dwarf from the irrlicht media. Bout the same speed as the md2!

Slightly tweaked version of the Irrlicht geomipmapping terrain demo with coldet. REALLY slow to load.

Two skinned squirrels exported with the Panda (.x format) from 3dsmax. (Akiko made these for Teenage Lawnmower back in the day) Slow! One gets about 30 fps.

Conclusion

So.. yeah, slow.

Is anybody getting better speed than this?  Am I doing something wrong?

If I export say, a squirrel as a solid mesh (no animation) I get 60 fps, so I guess the real bottleneck is in the animation math, not the triangles/texturing.

I have to say though, I really like how Irrlicht is laid out – it’s a great way to steal <ahem, borrow> a ton of easy to plug-in functionality.  It can load nearly everything! (Except animated Collada..)

Random thoughts

I can think of some ways to speed this up, for instance, one way would be to write an irrlicht program that converts skinned mesh anims to a morph/frame based one, then optimize the renderer for the iPhone,  should be way faster than even the .md2 renderer.  (So, mem/filespace exchanged for rendering speed.. could even avoid frame interpolation if you output the anim with enough frames maybe)

On the 3GS you could probably do a skinned mesh shader and just fly, not sure.  But I don’t even have a 3GS yet!  Meh!

Could probably drop the geomipmapping for the terrain and just dynamically create the render list based on terrain sectors in the players view and do a fog thing to hide the edges and see a big performance improvement for iPhone.