FCAT

Technology

Frame Capture Analysis Tool for VR Games

Smoothness is critical for VR gaming, and users can evaluate stutter that might affect game fluidity in a few different ways. The most common method is simply to experience VR and evaluate how it feels. Does it hitch? Is there stutter? Pan the view around and feel how smooth it is in motion.

However, this method is subjective.

Our newest iteration of FCAT, called FCAT VR, supports Virtual Reality (VR) by adding capture support for Oculus Rift and HTC Vive. FCAT analysis is an objective, data-based process that takes the guesswork out of VR performance testing.

FCAT VR is comprised of two tools: FCAT VR Capture and the FCAT VR Analyzer.

FCAT VR Capture:
FCAT Capture is a new frametime capture tool with a user interface similar to other frame capture tools (such as FRAPS). It uses NVIDIA driver stats, Oculus Event Tracing for Windows (ETW) events, or SteamVR's performance API data (for HTC Vive) to generate precise VR performance data. FCAT Capture works for all GPUs, independent of GPU vendor.

Most importantly, FCAT Capture works with popular VR Head-Mounted Displays (HMDs) to capture key performance events:

  • Total frametime
  • Application dropped frames
  • Runtime warp dropped frames
  • Asynchronous Space Warp (ASW) synthesized frames

From these events, we can draw meaningful conclusions about the GPU performance and the VR experience.

FCAT VR Analyzer:
Data generated by FCAT VR Capture can be easily dragged into the FCAT VR Analyzer. Here, it allows essential data such as frametime, dropped frames, synthesized (ASW) frames, and much more to be extracted and easily compared to other VR data. The analyzer also allows for the simple creation of frametime and dropped frame charts that can be saved and exported.

Frame Capture Analysis Tool for Desktop Gaming
GPU performance is often calculated by running benchmark games and recording the average Frames Per Second (FPS) using FRAPS or a similar tool. Unfortunately, many significant performance implications can be missed using this traditional method. We've found that the data reported by FRAPs doesn't match what you see on screen and feel in the game. So, in 2011, NVIDIA engineers began work on a new way to examine GPU performance in far greater detail.

These efforts resulted in FCAT (Frame Capture Analysis Tool). Measuring performance as it's delivered on a monitor, FCAT identifies dropped frames, runt frames, micro-stuttering, and other problems that reduce the visible smoothness of the action on-screen—even when running at sixty frames per second and above as reported by FRAPS. This in-depth examination of performance has helped us to fine-tune the last two generations of our graphics hardware while in development, resulting in a smoother gaming experience.

To show you FCAT and explain its inner workings, creator Tom Petersen put together the following video. It cuts through the technical jargon to detail the real-world benefits of FCAT for PC gamers:

 

As Tom mentions in the video, independent press sites such as PC Perspective and Tech Report have already integrated FCAT into their test suites. Check them out here


FCAT is helping to improve gaming by pushing us all to deliver better experiences. Understanding how GPUs affect perceived smoothness—and measuring it accurately—is the first step.