Star Engine

开发星际公民使用的游戏引擎


Star Engine 是开发星际公民曾使用过的游戏引擎,现已改为使用Amazon Lumberyard引擎[1]。 它是Crytek所开发的CryEngine 3引擎的大幅修改版,从最初在Crowdfunding campaign公布的引擎内实机演示开始使用。最后一次使用本引擎的相关更新是在3.8补丁[2]

在2016年12月23号,随着Star Citizen Alpha 2.6.0的公布,CIG同时宣布游戏的开发迁移至了Amazon Lumberyard游戏引擎。该引擎同样是基于CryEngine 3.8的修改版[3],但加入了对Amazon Web Service(AWS)的支持,以及云端计算的特性,以用于“支持开发发次世代级别的在线游戏”[4][5] . 目前并不确定CIG将Star Engine的功能整合进了哪个版本的Lumberyard引擎,也不确定CIG在未来将如何迭代这套开发工具。(截止到2016年11月,当前Lumberyard引擎的版本为 Beta 1.6)。

CIG工作室目前正负责引擎的开发,同时有一部分Crytek的前员工也参与来监管此项目[缺乏引证]

特色功能

虽然CIG时常公开他们的开发过程,但很少有引擎相关的开发信息会向大众公开。以下提到的引擎特性均来源于采访、每月的开发报告以及开发者评论。以下介绍的功能名字可能与CIG内部的命名有所不同,或并不准确。同时,有一部分功能已经被整合进了CryEngine 3.8/Lumberyard引擎,详细可参见Wikipedia-logo-v2.svg CryEngine

以下为自CryEngine3.8后,CIG开发的引擎功能。

主要特性

渲染

  • Object space shader damage (allows 4 different types of damage to be permanently inflicted on ships, including cutting holes, and blended seamlessly into the base shading)
  • Real time environment-probe capture and compression (avoids needing to bake probes in space and on planets)
  • Image based lens flares (use entire source image to simulate 4 different physically based lens distortions per colour channel on up to 20 individual elements)
  • Physically based bloom (wide exponential kernel based purely on light intensity)
  • Human eye exposure simulation (capture histogram of light intensity from both screen and surroundings, isolate range of light we intend to focus on, simulate both pupil and photo-pigment reactions for quick and slow reactions)
  • Major improvements to planar lights (far more physical basis now which results in major quality improvements)
  • Intelligent mesh-merging system (repeatedly searches for best bang-for-buck mesh merge opportunity in a scene until we hit a memory limit)
  • Upgraded volumetric fog (e.g. support for planar lights, light-boxes, env-probe priority sorting)
  • Major upgrade to shadow pool system (all lights share one giant pool for better dynamic resolution scaling, shadows can be cached between frames for better performance)
  • Render target pooling (shares memory between internal textures used in the renderer to vastly reduce VRAM usage)
  • Render to texture pipeline (ability to render secondary viewports with full or limited feature set to then be used as textures in the primary scene, e.g. video comms or holograms)
  • Tiled lighting upgrades (use rasterization light culling for greater efficiency, particle support)
  • Density based LOD algorithm (LODs change based on polygon density to ensure consistent appearance, less artist intervention, and promote more optimal art assets with fewer sub-pixel polygons)
  • GGX normal map filtering (gloss adjusted in mip-chain to best fit of our GGX lighting model to give the same results as super sampled normals)
  • Camera relative rendering (allows 64bit world without incurring any rendering performance hit by maintaining 32bit precision for rendering)
  • GPU Particle System (built from the ground up for efficiency, distinct from Lumberyards and CryEngine's GPU particle systems)
  • Various improvements to transparency sorting (generalized system, allow depth of field and motion blur to not effect nearby in-focus objects, order independent transparency for specific shaders such as hair)
  • Artist friendly profiler (captures statistics per art-team, and per area of the level allowing accurate breakdowns and quick diagnosing of performance issues)
  • Physically based atmospheric scattering
  • Hierarchical object management (efficient searches and culling, local coordinate frames for things like ships inside ships on planets which are rotating etc)[13]

Star Citizen Alpha 3.0.0中使用到的特性 [14]

  • P4K System - improved data handling system
  • Planetary Rotation
  • Temporal Supersampling (TSAA) - previously rendered frames are used to improve the anti-aliasing results on the new frame
  • Improved Screen Space Directional Occlusion (SSDO)
  • New Filmic Tone Mapping Curve (ACES)
  • PBR Glass - Glass (e.g. cockpits) can be rendered with phyiscs-based distortions, cracks, reflections and chromatic effects

更新计划 (截止至2017年10月)[14]

短期计划

  • Terrain Occlusion & Shadowing
  • Gameplay Driven Material Shaders
  • "Space Fog" (Gas Clouds in e.g. asteroid fields)
  • Improved Hair
  • New Shield Effect
  • Depth of Field Improvements
  • Colour Processing Improvements
  • New Motion Blur Implementation
  • Support for Complex Shading Models

中/长期计划

  • Object Container Streaming support on the low level/system side
  • Improved Planet Effects (shadows, clouds, etc.)
  • Improved Space Effects (stars, sun, rings, etc.)
  • Dynamic Global Illumination
  • Batching of physics-thread
  • Batching of render-thread
  • Vulcan backend support


工具及第三方软件

  • Kythera - AI middleware [15]
  • Vulkan API - 3D graphics and compute API [16]
  • Wwise - Sound Engine [17]
  • FMOD - (deprecated) Sound Engine [6]
  • DataForge [缺乏引证] - Data management, Ship & Weapons balancing [6]
  • StoryForge - Dialogue and Conversations system, built upon DataForge [8]
  • VERS 3D (formerly known as PlanetEd) - Editor for creating planets [18]
  • System Layout Tool - Star system layout and design [7]
  • Room Management System - (deprecated) System for players to manage their hangars; now changed and integrated in Item Port System [6]

相关视频

另行参见

引用

  1. 1.0 1.1 Gamers Nexus - Interview with Chris Roberts, summary
  2. Gamers Nexus - Interview with Sean Tracy, summary
  3. Erin Roberts: "Lumberyard is completely based on Cryengine", wccftech, Star Citizen Switches Engines: Move Along Folks, Nothing to See Here, Dec 24, 2016
  4. Star Citizen Newsletter - Alpha 2.6 with Star Marine!, December 23rd, 2016
  5. RSInotext.svg Clarification by Chris Roberts on the switch to Lumberyard
  6. 6.0 6.1 6.2 6.3 6.4 Monthly Report Oct 2014
  7. 7.0 7.1 Monthly Report Sept 2014
  8. 8.0 8.1 Monthly Report Nov 2014
  9. 9.0 9.1 9.2 9.3 9.4 Monthly Report April 2015
  10. Monthly Report May 2015
  11. Subscriber's Town Hall with Austin Developers
  12. Monthly Report June 2015
  13. Ali Brown comments on Star Engine renderer on Spectrum
  14. 14.0 14.1 CitizenCon 2017 Graphics Engineering Panel "Beyond the Cutting Edge"
  15. Kythera by Moon Collider
  16. RSInotext.svg Ali Brown (Director of Graphics Engineering) comment about Vulkan
  17. Wikipedia-logo-v2.svg Wwise
  18. PlanetEd reference

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