光线追踪 路径追踪
Unity’s ray tracing enables customers to create stunningly realistic real-time experiences using affordable hardware, unlocking new applications that were impractical just a few months ago.
Unity的光线跟踪使客户能够使用负担得起的硬件创建令人惊叹的逼真的实时体验，从而解锁几个月前不切实际的新应用程序。
At this point, nearly everyone with even a passing interest in real-time 3D graphics has seen the amazing video of a BMW M850i that we recently created in partnership with NVIDIA and Light & Shadows. The seamless blend between live-action video and ray traced rendering demonstrated in the demo is an incredible achievement. In a recent blog post, Dany Ayoub (3D Artist), Kate McFadden (Sr. Demo Artist), and Sebastien Lagarde (Graphics Lead) covered the technical aspects of ray tracing and how the demo was prepared. But there’s another side to the story – how ray tracing benefits customers. At Unity, we enjoy solving hard technical problems, but we’re even more passionate about enabling customer success. In this blog post, I’ll cover how you can put real-time ray tracing to work for you, and what to expect from Unity throughout 2019.
在这一点上，几乎每个对实时3D图形感兴趣的人都看到了我们最近与NVIDIA和Light＆Shadows合作创建的BMW M850i的惊人视频 。 该演示中演示的真人视频和光线跟踪渲染之间的无缝融合是令人难以置信的成就。 在最近的博客文章中 ，Dany Ayoub(3D艺术家)，Kate McFadden(高级演示艺术家)和Sebastien Lagarde(图形主管)介绍了射线跟踪的技术方面以及演示的准备方式。 但是，故事还有另一面–光线追踪如何使客户受益。 在Unity，我们乐于解决棘手的技术问题，但我们对使客户获得成功充满热情。 在此博客文章中，我将介绍如何使实时光线跟踪为您服务以及Unity在整个2019年的期望。
实时，负担得起的高保真–选择三个 (Real-time, affordable, high-fidelity – Pick three)
The classic “iron triangle” decrees that every project has three objectives – fast, cheap and good – and that a customer needs to decide which two of these to prioritize. Ray tracing in Unity shatters that iron triangle by enabling stunningly realistic visualization at real-time frame rates using widely available and relatively inexpensive computing hardware. It’s this combination that represents the key breakthrough. Research into ray tracing stretches into the earliest years of computer graphics, and it has long been possible to generate ray-traced images “offline” on render farms, though not in real time. More recently, real-time ray tracing has been available to customers who can afford compute clusters with hundreds (or even thousands) of CPUs. While these earlier implementations of the technology produce compelling visuals, simple economics dictates that their practical use is limited to high-end production companies and corporate design studios.
经典的“铁三角”法令规定，每个项目都有三个目标-快速，廉价和良好-客户需要确定优先哪个目标。 Unity中的光线追踪通过使用广泛可用且相对便宜的计算硬件以实时帧速率实现惊人逼真的可视化，从而打破了三角形。 正是这种组合代表了关键的突破。 对光线追踪的研究可以追溯到计算机图形学的最早年份，并且长期以来一直可以在渲染场上“离线”生成光线追踪图像，尽管不是实时的。 最近，实时光线跟踪已提供给可以负担数百个(甚至数千个)CPU的计算集群的客户。 尽管这些技术的较早实现产生了引人注目的视觉效果，但简单的经济学要求它们的实际使用仅限于高端制作公司和公司设计工作室。
With real-time ray tracing in Unity, the practical uses for this technology can now be extended to a much wider set of applications. What’s more, it’s simple to trade off performance and fidelity to precisely match the needs of each application. Do you have a need for ultimate visual quality? Increase the number of bounces calculated for each ray to more precisely calculate the behavior of light in a scene, yielding highly realistic appearance for transparent materials and for areas with complex shadows. At higher resolutions and bounce counts, frame rates may not be as smooth, but they will still be interactive, enabling you to quickly and efficiently tailor the composition, materials, lighting, and effects to create stills and videos without the delayed rendering of traditional processes. Do you need silky smooth frame rates? Then simply adjust resolution and bounce count to achieve your target frame rate.
通过Unity中的实时光线跟踪，该技术的实际用途现在可以扩展到更广泛的应用程序集。 而且，在性能和保真度之间进行权衡以精确地满足每个应用程序的需求很简单。 您是否需要极致的视觉质量？ 增加为每条光线计算的反弹次数，以更精确地计算场景中的光线行为，从而为透明材质和具有复杂阴影的区域提供高度逼真的外观。 在更高的分辨率和跳动计数下，帧速率可能不那么平滑，但是它们仍将是交互式的，使您能够快速有效地调整构图，材质，照明和效果以创建静态图像和视频，而不会延迟传统流程的渲染。 。 您是否需要柔滑流畅的帧频？ 然后只需调整分辨率和跳动计数即可达到目标帧速率。
准备好，瞄准，看看 (Ready, aim, see)
The most obvious application of affordable real-time ray tracing is to create individualized marketing experiences at scale. With Unity, it’s now feasible to deploy product configurators and other interactive experiences at retail locations, and ray tracing will extend the realism of these experiences even further. And while most consumers don’t yet own ray tracing capable hardware, it’s possible to stream content to consumer devices from a dedicated datacenter or the cloud.
负担得起的实时光线跟踪的最明显的应用是大规模创建个性化的营销体验。 使用Unity，现在可以在零售位置部署产品配置器和其他交互式体验，并且光线跟踪将进一步扩展这些体验的真实性。 尽管大多数消费者尚未拥有支持光线追踪的硬件，但仍可以将内容从专用数据中心或云流传输到消费者设备。
The benefits of real-time ray tracing extend beyond consumer uses. Designers, engineers, architects and other professionals no longer need to schedule scarce time on a large-scale compute cluster or wait hours for a render farm. Using Unity, designers and engineers can better assess the impact of lighting, shadows, glare, and reflections on the visibility of displays and controls. Within Unity, it’s easy to adjust material properties including specularity (glossiness) to assess appearance under different lighting conditions. Architects can accomplish similar tasks when designing exteriors and interiors. The fact that this work can be done in real time using conventional desktop computers (or even appropriately equipped laptops) enables radically accelerated design iteration, and ultimately the creation of more refined designs.
实时光线追踪的好处不仅仅局限于消费者。 设计师，工程师，建筑师和其他专业人员不再需要在大型计算集群上安排稀缺时间或为渲染场等待数小时。 使用Unity，设计师和工程师可以更好地评估照明，阴影，眩光和反射对显示器和控件可见性的影响。 在Unity中，可以轻松调整材料特性(包括镜面度(光泽度))以评估在不同光照条件下的外观。 建筑师在设计外部和内部时可以完成类似的任务。 这项工作可以使用常规台式计算机(甚至配备适当的笔记本电脑)实时完成的事实，可以从根本上加速设计迭代，并最终创建更精致的设计。
The creation of entertainment content can also benefit from real-time ray tracing. Real-time rendering is increasingly being used for previz and look development work in the media industry, and incorporating the realism of real-time ray tracing has the potential to improve these processes.
娱乐内容的创建也可以从实时光线跟踪中受益。 实时渲染正越来越多地用于媒体行业中的预览和外观开发工作，并且将实时光线跟踪的真实性纳入其中可以改善这些过程。
我真的可以这样做吗？ (Can I really do this?)
In short, yes. Unity ray tracing is built on top of the High Definition Render Pipeline (HDRP) and an experimental version (Unity DXR) can be downloaded from GitHub today. There are certain constraints that are explained in the documentation, but the bottom line is that you can add ray tracing to an existing HDRP scene. You’ll need compatible NVIDIA RTX hardware and the appropriate version of Windows 10 – specific requirements are detailed in the GitHub README. The current experimental version is a great place to start to learn real-time ray tracing and evaluate how it can benefit your specific use cases, however, we recommend that you not use the experimental version for production work. We’re actively developing and constantly updating this technology, and plan to release it a Preview version in Fall 2019. Preview releases are generally suitable for starting new production projects, with the understanding that these packages are not fully validated, and some details are subject to change between Preview and Verified release.
简而言之，是的。 Unity光线跟踪建立在 高清晰度渲染管线(HDRP) 之上， 并且 可以从GitHub立即下载 实验版本(Unity DXR) 。 文档中说明了某些限制，但最重要的是您可以将射线跟踪添加到现有的HDRP场景。 您需要兼容的NVIDIA RTX硬件和适当版本的Windows 10-特定要求在GitHub README中有详细说明。 当前的实验版本是学习实时光线跟踪并评估其如何使您的特定用例受益的好地方，但是，我们建议您不要将实验版本用于生产工作。 我们正在积极开发并不断更新该技术，并计划在2019年秋季发布它的预览版。预览版通常适合于启动新的生产项目，但要了解这些软件包尚未得到充分验证，并且有些细节尚待确定。在预览版和验证版之间切换。
We’re excited about making this technology available to the Unity community, but we’re even more excited to see what you do with it. We’d love to hear your ideas about how you can put ray tracing to work, and if you create projects that you’re able to share publicly, please let us and everyone else know. In the comment section below please share your ideas, hopes and dreams – and where to find your ray tracing demos. And to anticipate a question you are likely asking already, no we can’t share the BMW project. We do want to see what you do with your own models though!
我们很高兴能将这项技术提供给Unity社区使用，但是看到您如何使用它，我们会更加兴奋。 我们很想听听您关于如何使光线追踪起作用的想法，如果您创建可以公开共享的项目，请告知我们和其他所有人。 在下面的评论部分中，请分享您的想法，希望和梦想，以及在哪里可以找到射线追踪演示。 而且，要预料到您可能已经提出的问题，不，我们不能分享BMW项目。 我们确实想看看您如何使用自己的模型！
Learn more about our solutions for the automotive and transportation industry here.
在此处 了解有关我们为汽车和运输业提供的解决方案的更多信息 。
翻译自: https://blogs.unity3d.com/2019/04/26/ray-tracing-what-does-it-mean-to-you/
光线追踪 路径追踪