c++ - Rendering performance in FlasCC + UDK when compared to Stage3d and UDK on Windows?

Adobe recently released the Flash C++ Compiler, which UDK uses to target Flash Player.

Developers can now access UDK for browser applications. Does this mean greater performance than using a Stage3D engine (Away3D 4) and how much of a noticeable difference in performance would it make in rendering speeds?

Is there any benchmark you could propose that would allow to compare them fairly? I am asking this to help myself understand the consequences in performance for deciding to use UDK in a browser based game. I would also like to know how it compares with UDK running natively in Windows?

I am not asking which technology to use or which is better. Only interested in optimizing rendering speed in a 3d browser game with flash.

Answer

Rendering speed for 3D FlasCC games/apps is likely to be similar to C++ apps for obvious reasons - the actual rendering takes place on the GPU. Flash includes a cross-platfrom shader language (AGAL) to describe GPU kernels (programs run per pixel on the GPU).

For CPU/computing speeds however, my tests have shown that the Alchemy toolkit at its best reaches 15% the speed of MS VC++ on Windows (with a simple encryption function operating on an array of bytes). Since Alchemy is now FlasCC, there may be improvements. Some benchmarks for the latest FlasCC are available here, that compare a set of C++ programs running as an EXE and in Flash Player.

This essentially comes down to:

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  Anything you can move to the GPU can possibly be done close to native speeds. This includes rendering, lighting, mip-mapping, and to some extent physics operations (depends on the library)

  
  


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  Anything still done on the CPU will be a few times slower than C++, so don't expect to have a million moving objects on screen with full physics even if you can do that with the native (C++) library.

  
  


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  Flash vector graphics does not use the GPU and is rendered fully on the CPU. So if you need HUDs (heads up displays) with high-performance 3D vector rendering like what Scaleform provides for C++ apps, don't expect that to be easily possible in Flash Player, unless you're willing to roll your own 3D vector renderer that takes advantage of the GPU to composite vector shapes.