- Ephemeris - Skydome System
- Added Procedural Night Sky and Star-field - the night sky's nebula colors are now customizable
- Added Glow effects on Sun and Moon
- Fix the issue that Godrays can be drawn on unexpected area
Click on the following screenshot to see a movie:
- New Light and Shadow Playground: we rebuild the light and shadow playground by using the St. Miguel art assets and adding some new shadowing techniques:
- Exponential Shadow Map - this is based on Marco Salvi's @marcosalvi papers. This technique filters out the edge of the shadow map by approximating the shadow test using exponential function that involves three subjects: the depth value rendered by the light source, the actual depth value that is being tested against, and the constant value defined by the user to control the softness of the shadow
- Adaptive Shadow Map with Parallax Correction Cache - this is based on the article "Parallax-Corrected Cached Shadow Maps" by Pavlo Turchyn in GPU Zen 2. It adaptively chooses which light source view to be used when rendering a shadow map based on a hiearchical grid structure. The grid structure is constantly updated depending on the user's point of view and it uses caching system that only renders uncovered part of the scene. The algorithm greatly reduce shadow aliasing that is normally found in traditional shadow map due to insufficient resolution. Pavlo Turchyn's paper from GPU Pro 2 added an additional improvement by implementing multi resolution filtering, a technique that approximates larger size PCF kernel using multiple mipmaps to achieve cheap soft shadow. He also describes how he integrated a Parallax Correction Cache to Adaptive Shadow Map, an algorithm that approximates moving sun's shadow on static scene without rendering tiles of shadow map every frame. The algorithm is generally used in an open world game to approximate the simulation of day & night’s shadow cycle more realistically without too much CPU/GPU cost.
- Signed Distance Field Soft Shadow - this is based on Daniel Wright's Siggraph 2015 @EpicShaders presentation. To achieve real time SDF shadow, we store the distance to the nearest surface for every unique Meshes to a 3D volume texture atlas. The Mesh SDF is generated offline using triangle ray tracing, and half precision float 3D volume texture atlas is accurate enough to represent 3D meshes with SDF. The current implementation only supports rigid meshes and uniform transformations (non-uniform scale is not supported). An approximate cone intersection can be achieved by measuring the closest distance of a passed ray to an occluder which gives us a cheap soft shadow when using SDF.
To achieve high-performance, the playground runs on our signature rendering architecture called Triangle Visibility Buffer. The step that generates the SDF data also uses this architecture.
Click on the following screenshot to see a movie:
The following PC screenshots are taken on Windows 10 with a AMD RX550 GPU (driver 19.7.1) with a resolution of 1920x1080.
Exponential Shadow Maps:
Adaptive Shadow Map with Parallax Correction Cache
Signed Distance Field Soft Shadow:
Signed Distance Field Soft Shadows - Debug Visualization
The following shots show Signed Distance Field Soft Shadows running on iMac with a AMD RADEON Pro 580
The following shots show Signed Distance Field Soft Shadows running on XBOX One:
Readme for Signed Distance Field Soft Shadow Maps:
To generate the SDF Mesh data you should select “Signed Distance Field” as the selected shadow type in the Light and Shadow Playground. There is a button called “Generate Missing SDF” and once its clicked, it shows a progress bar that represents the remaining SDF mesh objects utilized for SDF data generation. This process is multithreaded, so the user can still move around the scene while waiting for the SDF process to be finished. This is a long process and it could consume up to 8+ hours depending on your CPU specs. To check how many SDF objects there are presently in the scene, you can mark the checkbox "Visualize SDF Geometry On The Scene".
- Android: we switched from AndroidStudio to Visual Studio, because the AndroidStudio environment didn't allow us to work effectively and integrating it into our Jenkins test system made the build time explode.
- Vulkan:
- support of GPU assisted validation
- new Vulkan SDK 1.1.114 is supported
- Art package: we updated the St. Miguel scene with colored flags for the future Aura Global Illumination example. Because it is used by several unit tests, you want to download the art package again. See the Install instructions below for how to do this.
P.S: we have a new logo :-)