{"id":440,"date":"2009-12-01T23:59:46","date_gmt":"2009-12-01T14:59:46","guid":{"rendered":"http:\/\/www.codedojo.com\/?p=440"},"modified":"2011-08-06T11:56:30","modified_gmt":"2011-08-06T02:56:30","slug":"development-diary-more-irrlicht-on-the-iphone-pvrtc-mipmaps-lightmaps","status":"publish","type":"post","link":"https:\/\/www.codedojo.com\/?p=440","title":{"rendered":"Development Diary – More Irrlicht on the iPhone (pvrtc, mipmaps, lightmaps)"},"content":{"rendered":"

Some more iPhone benchmarks and tests with everybody’s favorite difficult to pronounce<\/a> 3d rendering framework!<\/p>\n

Thumb mode and floating point:\u00a0 Just don’t<\/strong><\/h2>\n

\"iphone_irrlicht_md2_again\"<\/a><\/p>\n

Ok, first, I was an idiot before and somehow was still compiling in thumb mode. I know not to do that!<\/p>\n

Somehow the setting was removed but I guess the default is ON even with it missing or something.\u00a0 After adding it by hand it the math-heavy md2 anim rendering test went from 31 fps to 60+ fps.<\/p>\n

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.<\/p>\n

Irrlicht and Quake 3 style .bsp demo<\/strong><\/h2>\n
\"Irrlicht's<\/a>

Irrlicht's .bsp map demo on iPhone using pvrtc4 textures with mipmaps and player collision enabled<\/p><\/div>\n

I was expecting Irrlicht to do some kind of wicked optimizations when rendering a .bsp map.\u00a0 Nope, it does nothing special.\u00a0 You CAN load it into an octree but if OCTTREE_USE_HARDWARE is defined it renders the whole mesh anyway. (?!!?) \u00a0 If that flag isn’t defined, it does render less primitives but without using VBOs so it’s way slower anyway.<\/p>\n

This forum thread<\/a> may be of interest about that.<\/p>\n

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.\u00a0 Strange, I would have expected it to noticeably help.<\/p>\n

(this section was updated Dec 2nd after Tonic pointed out that you can use VBO’s with Octrees…)<\/p>\n

Adding iPhone controls<\/strong><\/h2>\n

As you can see in the screenshot above I’ve added a basic wolf3d control scheme to get around.<\/p>\n

I use my own engine to handle the GUI overlay\/handling (it draws after Irrlicht is done)\u00a0 and just have it controlling Irrlicht’s FPSControlComponent.<\/p>\n

I use camera->setTarget() to look up and down, and I fake UP\/DOWN\/LEFT\/RIGHT key movement by sending pDevice->postEventFromUser() messages.\u00a0 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.<\/p>\n

Do using compressed textures help the FPS on the iPhone?<\/strong>
\n<\/strong><\/h2>\n

Short answer, a little.<\/p>\n

I added CImageLoaderRTTEX to Irrlicht so it could load my own texture format.\u00a0 It’s sort of a container that houses multiple formats including pvrct4, pvrct2, 4444 rgba, 565 rgb, etc.\u00a0 It does extra stuff that normal .pvr’s don’t, like remember the original image size before padding or stretching.<\/p>\n

I also modified the b3d and .bsp loader to look for textures with my .rttex file extension first.<\/p>\n

Some rough numbers with the quake style .bsp map collision disabled:<\/p>\n