* Provides mid-range stable AO for dynamic rigid meshes
* Movable sky lights are now supported, and distance field AO is used for shadowing Movable sky lighting from dynamic scenes
* Static meshes are preprocessed into signed distance field volumes at mesh build time when the r.AllowMeshDistanceFieldRepresentations project setting is enabled
* Non-uniform scaling does not work with this method (mirroring is fine), animating through world position offset also causes artifacts as the two representations diverge
* Occlusion is computed along cones to reduce over-shadowing, object distance fields are operated on directly (no hierarchy) to obtain enough resolution to prevent leaking, visibility traces are done with cone stepping to allow better parallelization, and shading is done adaptively in space and time using the surface cache.
[CL 2093556 by Daniel Wright in Main branch]
Fixes TTP #336826 where DTYPE_Realtime soundwaves were silently failing in OpenAL under Linux (and perhaps HTML5, too). May also help other platforms (IOS?) where DTYPE_Realtime is not implemented.
#codereview Matthew.Griffin, Marc.Audy
[CL 2088573 by Dmitry Rekman in Main branch]
You can now access raw platform-specific texture resources for D3D11 or OpenGL by calling GetNativeResource() on a texture object.
Thanks to Coherent for submitting this change. https://github.com/EpicGames/UnrealEngine/pull/138
[CL 2079518 by Mike Fricker in Main branch]
* It was picking the wrong clear method which is fixed now (D3D11 problem)
* added check to find such a case earlier
[CL 2068632 by Martin Mittring in Main branch]
#ttp 331829 - Mobile Preview in Editor
#proj Engine
#branch UE4
#summary First pass of changes to remove GRHIFeatureLevel, allowing for multiple scenes with different feature levels to exist. First step towards dynamic mobile preview in the editor.
#change Added GMaxRHIFeature level which contains the highest supported feature level on this machine
#change Added a cvar "r.FeatureLevelPreview" which, when set to 1, enables a feature level selection in the quick settings menu. Not wired up to anything at the minute
#change Added a feature level variable to FScene, which is currently initialized to whatever GRHIFeatureLevel is. Accessed with GetFeatureLevel()
#change Added a helper accessor GetFeatureLevel() to FSceneView which gets the feature level from the relevant scene. Purely to reduce the amount of typing needed to get to a feature level
#change Many changes across the renderer to try and read the current feature level from the view or scene. Not everything is done yet, but this is almost all of the "easy" stuff. As there is still just a global feature level in the engine, nothing should change.
[CL 2066905 by Graeme Thornton in Main branch]
