View Full Version : Some UT3 tech info

05-30-07, 01:13 PM
This was on the Epic forums, translated from a german PC games magazine interview..

Overview of the most important rendering features:

- multi-threaded renderer (4+ threads)
- 16 Bit per componenent HDR-Pipeline
- runs on 64 Bit operating systems
- (confirmed) performance advantages through SLI (most likely Crossfire as well)
- post-processing effects (some examples): motion blur, depth-of-field blur, bloom
- deferred shading
- physics: Ageia PhysX engine
- 300 - 1.000 visible objects per scene
- huge scenes typically consist of 500.000 to 1.500.000 triangles
- normal maps and texture maps usually have a resolution of 2.048 x 2.048

Important questions, answered by Tim Sweeny, lead developer at Epic Games:

PCGH: Is there a possibility to make deferred shading and edge-smoothing work at the same time on DX9 graphics cards?
Epic: Unreal Engine 3 uses deferred shading to speed up the calculation of
dynamical lighting and shadows. Integrating this feature together with
multi-sampling requires control of the edge-smoothing at a much deeper level than the DX9 interface can provide. So, on the PC, multi-sampling will only be
supported under DX10.

PCGH: How do the general hardware requirements look like?
Epic: Since optimization work is still ongoing, these details may change every
day. Generally speaking, the game runs quite smooth with DX9 hardware released by NVidia and Ati since 2006. On high-end cards, including the DX10 models, UT3 runs incredibly smooth already. Additionally, we also support shader 2.0 graphics hardware, with only a few technical limitations.

PCGH: Will SLI and Crossfire provide significant advantages?
Epic: We're testing SLI configurations on a regular basis. Their positive
influence can be felt significantly, especially at higher resolutions. So, if one
wants to have full details at very high resolutions, a SLI-system would be the
ideal way to secure optimal performance. We had no opportunity to test crossfire systems yet, but we are expecting similar results.

PCGH: How exacly are you utilizing the functions of Direct X 10?
Epic: Unreal Tournament 3 will ship with full DX10 support, with multi-sampling
being the biggest visible benefit of the new graphics interface. Additionally,
with DX10 under Vista we have the possibility to use the video memory more
efficently, to be able to display textures with a higher grade of detail as it
would be possible with the DX9 path of Vista. Most effects of UT3 are more bound to the fillrate than to basic features like geometry processing. That's why DX10 has a great impact on performance, while we mostly forgo the integration of new features.

PCGH: Will UT3 players be able to benefit from a 64 Bit environment and is there a 64 Bit version anyway?
Epic: To assure compatibility, we tested UT3 with Vista x64 as well. Nonetheless, we're planning to wait and see first, until the OS and its applications will have ripened, before we'll be taking further steps in the 64 Bit direction. With UT2004 we were one of the first developers who ported a title for Windows XP x64. We would've liked to do this with UT3 and Vista x64 as well as shifting all the PCs we're currently developing on to the 64 Bit version of Vista. Unfortunately, full software and driver compatibility isn't there. The basic OS runs stable and it's fun to work with it isolated. But as soon as you want to print something or want to run Maya or 3DSMax together with some third-party plugins you'll get massive problems. But I am sure those can be fixed via service packs and software updates, so PCs with 4 to 8 gigs of ram can establish themselves during the next 12 months.

PCGH: What is the maximun number of threads that can be calculated separately? Will there be a performance-boost if a quad-core system will be used?
Epic: We're able to scale the thread-structure pretty well. There is a primary
thread for the gameplay and a second one for rendering. On systems with more than 2 cores we run additional threads to speed up various calculation-tasks, including physics and data-decompression. So the overall performance benefits greatly from a quad-core processor. Although we haven't looked into the matter yet, I expect an even further performance increase through CPUs with more than 4 cores in future UE-based games.

05-30-07, 01:15 PM
LOL, sorry. Just noticed this was already posted.