维塔数码（Weta Digital）是一家全球领先的综合性视觉效果公司，总部设在新西兰首都惠灵顿。公司成立于1993年，新西兰导演彼得·杰克逊与好友理查德·泰勒、吉米·塞尔柯克共同创建。维塔数码曾5次获得奥斯卡最佳视觉效果奖。我们熟知的电影如《魔戒三部曲》、《金刚》、《阿凡达》等片中的视效均出自于维塔的制作团队。维塔数码积极开拓市场营销，与中国的公司有不少业务往来。该公司具有接待外国政要的经历，英国查尔斯王子和文莱王储等曾造访过该工作室。
Distributed ray tracing algorithms are widely used when rendering massive scenes, where data utilization and load balancing are the keys to improving performance. One essential observation is that rays are temporally coherent, which indicates that temporal information can be used to improve computational efficiency. In this paper, we use temporal coherence to optimize the performance of distributed ray tracing. First, we propose a temporal coherence-based scheduling algorithm to guide the task/data assignment and scheduling. Then, we propose a virtual portal structure to predict the radiance of rays based on the previous frame, and send the rays with low radiance to a precomputed simplified model for further tracing, which can dramatically reduce the traversal complexity and the overhead of network data transmission. The approach was validated on scenes of sizes up to 355 GB. Our algorithm can achieve a speedup of up to 81% compared to previous algorithms, with a very small mean squared error.
We present Pahi, a unified water pipeline and toolset for visual effects production. It covers procedural blocking visualization for preproduction, simulation of various water phenomena from large-scale splashes with airborne spray and mist, underwater bubbles and foam to small-scale ripples, thin film and drips, and a compositing system to combine different elements together for rendering. Rather than prescribing a one-size-fits-all solution, Pahi encompasses a number of state-of-the-art techniques from reference engineering-grade solvers to highly art-directable tools. We do a deep dive into the technical aspects of Pahi components and their interaction, and discuss practical aspects of its use on Avatar: The Way of Water. We were honored to be awarded the Visual Effects Society (VES) 2023 Emerging Technology Award for this work.
Avatar: The Way of Water, presented Wētā FX with the challenge of delivering visuals of an unprecedented level of complexity and quality. To support the filmmaker's creative vision, Wētā FX sought to ensure it had burst compute capacity available through scalable cloud resource.
Avatar: The Way of Water, presented Wētā FX with the challenge of delivering visuals of an unprecedented level of complexity and quality. To support the filmmaker's creative vision, Wētā FX sought to ensure it had burst compute capacity available through scalable cloud resource. In this talk we aim to present our approach to this problem in the cloud rendering space. We will provide an overview of the deployment of a large-scale hybrid cloud render-farm, diving into areas we found challenging and of particular interest to the wider VFX community. Namely the deployment of a custom-built NFS re-export cache tweaked to deal with high latency, our approach to maintaining performant storage in the cloud, our solution to scheduling a large-scale spot fleet across 3 AWS regions and various challenges encountered when rendering at scale in the cloud. Within each section we intend to present scalability issues encountered, detail various challenges and our approaches to overcome them.
