iPhone и iPod Touche - спецификации и ограничения в 3D

[BEEF34T3R]

Нашёл в документаци Stonetrip ShiVa: http://stdn.stonetrip.com

Designing for iPhone

System Specifications

iPhone 3G

Screen 480×320 px, 3.5 in (89 mm), color LCD, 3:2 aspect ratio, capable of up to 262,144 colors.
Camera 2.0 megapixel
Operating system iPhone OS 2.2 (Build 5G77)
Input Multi-touch touchscreen
CPU 620 MHz ARM 1176, underclocked to 412 MHz
GPU PowerVR MBX Lite 3D
Memory 128 MB DRAM
Storage Flash memory 4, 8, or 16 GB
Networks Quad band GSM 850 900 1800 1900 GPRS/EDGE; 3G also includes: Tri band UMTS/HSDPA 850, 1900, 2100, A-GPS
Wi-Fi 802.11b/g
Bluetooth 2.0+EDR

iPod Touch 2G

Media Flash Memory 8, 16, or 32 GB
Operating system iPhone OS; 1st generation: 2.2; 2nd generation: 2.2
Input Multi-touch touchscreen
CPU 620 MHz ARM, underclocked: 1st gen - 412 MHz (with software update 1.1.2) ARM11 2nd gen - 532 MHz
GPU PowerVR MBX Lite 3D
Memory 128 MB DRAM
Display 480 x 320 3.5" color LCD 3:2 aspect ratio, 163 pixels per inch (ppi)
Connectivity USB 2.0
Wi-Fi 802.11b/g


Device Limitations

Textures

aspect ratio 1:1, textures have to be square and a power of two (e.g. 8x8, 16x16, 64x64; 64x128 f.i. is bad)
min size 8x8
max size 1024x1024
amount 1 texture plus shadow map or 2 textures, blended by "modulate" and "saturate" only
alpha channel alpha is allowed, but not recommended due to performance reasons, better use masks
normal mapping no
specular mapping no
environment/sphere mapping no
texture clips yes
texture scrolling/scaling modifier accepted
texture filtering mode GPU "default mode" is used (bilinear mipmaped)
material settings ambient-diffuse-emissive-specular-shinyness, and emissive will only act as a constant color not depending on the scene and lights

Shaders

normal mapping no
specular mapping no
environment/sphere mapping no
shadow mapping yes
texture blending "modulate" and "saturate" only, but only if no shadow map is used (2 texture slot limitation)
reflection no, but can be simulated by inverting/mirroring the geometry
refraction no

Dynamic Shadows

no dynamic shadows allowed. fake dynamic shadows with a flat black (transparent) sprite that lies flat on the ground, if needed.

Dynamic Lights

The hardware supports up to 8 dynamic lights, 1-2 per oject is the recommended amount. "receive per vertex" is the only accepted setting.

Environment

fog yes, no restrictions
camera view distance unlimited, but relies on a 16bit z-buffer, so be careful: keep the range as small as possible to avoid Z-fighting

Particle systems

max particle count per scene depends on the screen size of the particles (alpha blending limitations)
max particle count per emitter no more than 256 if you want good performances, but again it depends on the screen size of the particles

Sounds and Music

music length is unlimited, but slow, as it's going to be streamed, better use short sounds (<10s)
sounds per sound bank unlimited
format 16bits, mono, 44100 Hz or less (lesser will be faster)

In Game Video

the current firmware dows not allow to play custom videos inside a game application.
> NEW: S3DAuthoringTool for iPhone version 1.9 allow you to add a startup fullscreen movie (still in a "beta" state).

Number of Polygons and Animation

max polys visible at the same time 7.000 for a gool frame rate, but tested with lot more, and it "works" (don't crash)
max polys per scene limited to 24Mb Texture + Vertex Buffers memory
max poly per object depends on the number of visible objects, but again, "lesser is better"
animation limit per anim bank none
bones count limit "lesser is better" but no limitations (from 0 to 16 is a good value)
bones per vertex limit really try to use 1 or 2, but limited to 4.

Keys and Input

available controls accelerometer, mouse and touch handlers
system reserved home button, side/volume buttons

Misc

Application Size Limit none, applications can be fairly big, >100MiB
Framerate monitor is limited to 60Hz, any fps value >15 is good.

[gnoblin]

Важно не количество поликов, а количество вертексов (на оф форуме все говорят про 7.000).
Еще говорят, что геометрия играет вторичную роль - более важно количество draw calls.

[Neodrop]

Хм... Кажется, всё-таки 7000 полигонов. Трианглов.

[gnoblin]

Ни фига!).

[Neodrop]

Какая разница? Для плоскости, колличество вертексов и трианглов разница на две вершины. Включи математику.

[Neodrop]

Важно не количество поликов, а количество вертексов (на оф форуме все говорят про 7.000).
Еще говорят, что геометрия играет вторичную роль - более важно количество draw calls.

Итак, вот цитата из письма от Unity Support :

Be aware that certain Unity features are not supported for iPhone development, as they are too processor intensive. This includes the terrain engine, movie textures, plug-in support, render to texture, built-in multiplayer, dynamic lighting and the locomotion system. The physics system works very well if you avoid mesh colliders. We also recommend you target your design with 7,000 - 10,000 viewable polys on-screen at any time for the best frame rate.

[andru]

В оф примере от юнитеха iPhone Multiplayer Tutorial больше 10k, мне кажется это не предел. Может быть кто-нибудь глянет как статистика в Penelope. Понятно что многое зависит не от количества а от качества и от самого проекта, просто интересен приблизительный предел!

[andru]

Быстрый взгляд на Penelope 15 - 20k триугольников и 5 - 10 мб текстур.

[BEEF34T3R]

На 3Gs я гонял оттекстуренные модельки и на 100000 треугольников - подлагивало, но не критично, до 70000 - вообще отличный FPS
Хотя моя модель универа ( viewtopic.php?p=10622#p10622 ) на 25000 заметно подлагивает, но здесь уже всё упирется в филлрейт текстурирования, т.к. запускал её без мипмэппинга, а там более 100 текстур до 512х512.

[Neodrop]

Ну, это как всегда - проблема ДравКоллов

[megafanat]

alpha channel alpha is allowed, but not recommended due to performance reasons, better use masks

А подскажите пожалуйста, что значит использовать маски для прозрачности, в терминах Unity3d?
Если имеется в виду прозрачность по заданному цвету, то я в списке прозрачных(Transparent) материалов не нашел материал, в котором можно задать прозрачность по цвету.