Bipul Mohanto

Bipul Mohanto

Doctoral Researcher@ Foveated Rendering | 3D Graphics Rendering| Global Illumination | Multi-View Rendering | Applied Human Perception | Color Science | Computer Vision

Uniform Evaluation Metrics

1 minute read

Published:

The following (work in progress…)

The following metrics are full-reference metics like the conventional PSNR and SSIM.

Black Box Approaches

1. NVidia’s FLIP

FLIP is an excellent tool for visualizing and communicating errors in the rendered images, both for low dynamic range (LDR) and high dynamic range (HDR). Big thanks to the NVlabs for making the tool publicly available with the source code. The FLIP is a command line interface (CLI) tool. I am on Windows platform:

  1. First, git clone --recursive https://github.com/NVlabs/flip.git, then cd flip
  2. BUILD:
    mkdir build
cd build
cmake ..
cmake --build .

    After this, the flip.exe should be under build/Debug. Similar way this can be extended to Debug and Release version. As per discussion, Release mode performs better

// for Release
mkdir Release
cd Release
cmake -DCMAKE_BUILD_TYPE=Release ..

// for Debug
mkdir Debug
cd Debug
cmake -DCMAKE_BUILD_TYPE=Debug ..
  1. RUNNING
    // go to Release/Debug folder and run
.\flip.exe -r .\reference.png -t .\test.png
// similarly
.\flip.exe -r .\reference.exr -t .\test.exr

    Visually, color represents the error map. Black means no perceived error, and yellow represents high error. For more details, see the Technical Blog and the Flip Publication.

There is an UI version of FLIP implementation, named as FLOP. Find in git with the blog explaining every step clearly. However, I guess the repository is not well-updated (2025) and there are several bugs that need to be resolved.

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tauray

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At the time of writing this (October, 2025), there are limited publicly available rendering engine that works for real-time stereo path tracing. The slow convergence with pixel dense display in VR is limiting real-time stereo path tracer. However, with the RT-core and GPU architecture improvements, I am noticing the recent trend of physically accurate light simulation in real-time rendering, e.g., games. Therefore, definitely with time, the real-time stereo path-tracing (and with other advanced global illumination algorithms) would be a real thing once we will overcome frame-rate constraint. Physically-accurate light simulation will minimized the difference between real and virtual world and extend the path of true immersion. Currently, 90 fps has become a golden standard for VR. However, the higher is the better for immersion.

Tamashii Beginner Tutorial

1 minute read

Published:

Tamashii is an excellent scientific rendering framework under development by the Department of Computer Graphics, TU Wien. Its main goal is to simplify the creation of research applications in the field of computer graphics by providing a fundamental structure in the form of libraries implementing resource loading, input handling, user interface creation, a complete rendering framework, and graphics API abstraction. The backend graphics API is Vulkan. However, Tamashii only supports single display systems, and \textbf{has not been modified for VR.}