Now that the Acceleration expansion pack and FSX SP2 have finally RTM'ed, I can start discussing some of the specifics relating to the changes and improvements made to both of these. I know this has already been covered in other blog posts but for this post I wanted to start with an overview of the upcoming changes. Of course, since I am one of the graphics engineers on the project, my future posts will focus mostly on the graphical improvements and also improvements and changes which are related to the DirectX 10 support introduced by SP2. Before I start, I wanted to note that we purposefuly RTM'ed on the expansion pack and SP2 at the same time so that the Acceleration Pack does also contain (and takes advantage) of all the bug fixes as well as performance and graphical improvements.

As Phil Taylor mentioned on his blog:

Acceleration Pack looks really good, and for the $30 US list price there is a lot of value with 3 aircraft (F-18 jet, P-51 racer, EH101 helo), along with 30+ missions and several new “sim” features like a functional carrier, slingloads and hoists for the helo, as well as the multiplayer racing experience. And I am probably forgetting features. There is quite a bit of value there. Acceleration will be available in late October. FSX-SP2 will be available sometime after Acceleration Pack and before Christmas. Please note both SP2 and Acceleration Pack will require FSX-SP1 to be installed. As I have previously stated, SP2 will include DX9 fixes as well as DX10 support. So with the release of SP2, Aces will have fulfilled its commitment to 2 updates for FSX RTM customers in 2007.

I want to make clear two important details about the DX10 part of Acceleration and SP2:

1) From a feature perspective, we do not match the magic screenies item-for-item because those screenies ignored an important visual element—the aircraft. We added virtual cockpit shadows to the work list because this feature further enhances the immersion. Of course, we also faced schedule and other constraints.

2) We are not promising runtime backwards compatibility in the current DX10 code path now or in the future. This is for two reasons:

a)The first is to send a message that we are going to change the backwards compatibility story moving forwards.

b)The second is practical, in that continuing to provide the backwards compatibility we do is a huge drag on forward progress. Spending time on 4 or more code paths (FSX DX10, FSX DX9, FS2004, pre-FS2004) costs us time that could be spent polishing the existing features, working on resource management to fully eliminate out of memory errors, and working on performance. We have to change that balance and in the DX10 preview you can see the first notice of that. Yes, we know we have to address some features that are not possible using the FSX SDK in future SDKs so that 3rd party developers are enabled and do not depend on these old techniques and we accept that. Because of these two issues, we are labeling the DX10 support a “preview” in the UI. We expect it will add value; but we are not expecting the DX10 path to replace the DX9 path as the primary experience in FSX and expect third parties to author to the DX9 path in the large. And yes most add-ons should continue to work in the DX9 code path in Acceleration/SP2, as long as they don’t depend on the old BGL compatibility path. An example that no longer works is the B-307 Stratoliner, it uses a decal alpha technique that we didn’t get re-enabled in either DX9 or DX10 after the re-plumbing work involved with SP2.

 I know some are going to be disappointed, and some disappointment is reasonable. I will be the first to state that Aces releasing the magic screenies was flat out a mistake; but us not matching that level of “vision” ( and that is what the magic screenies were ) is not a cause for a flame war against Aces or DX10. I should note, for instance, that the DX10 code path performs better under load than the DX9 code path, and this means the DX10 features are more useable. And DX10 does look better, both in the cockpit and in the world.

So what are the overall changes with SP2? Below is a breakdown of the enhancement and fixes which can be found for SP2 when running on either DX9 or DX10... 

FSX SP2-DX9  

Here is a list of what is in SP2 from a “global install perspective” and not just on Vista when DX10 is active:

Fixes and Features Core and Graphics

1) 8-core bug fix

2) 3G enabling FSX and Autogen memory use optimization

3) Exterior shadow quality improvements

4) Optimization of terrain IO for photo-scenery and “scenery load out of the zone” fixes to help reduce blurries

5) More batching of Autogen. This will help in areas where a lot of custom objects of the same material are authored and complements the SP1 batching work.

6) 737 and A321 night/taxi light fix with new models

7) Raindrops in the 2D cockpit

Audio, International, UI

8) Audio fix for soundcard/usb to speakers/headphones on Vista

9) Various internationalization fixes

10) Saving undocked panels

11) UI fix for flight list to be alpha-sorted when "Title" is clicked Multiplayer

12) Multiplayer compatibility with XPack for free-flight. With all the changes in Acceleration, SP1 is not free-flight compatible. SP2 addresses that. 

13) Multiplayer fixes for

a) when using DIRECT CONNECT, FSX now remembers the last IP used

b) COM1 shared cockpit sync  

FSX-SP2 DX10 

The features we do have are:

1) VC shadows

2) HDR Bloom

3) Water enhancements

4) Efficiency improvements via more Autogen batching, more efficient shaders, and a more efficient method of generating bloom.

Over my next set of posts, I will start covering some of the graphical specifics and go into more details. But for now, this should give a good idea of "things to come".