About

This is a standalone Environment Map Prefiltering Program for IBL(Image Based Lighting) of gltf spec.

Theory

For the theory behind this program, please refer to this article.

Building

Install CMake 3.10.2+
Install Visual Studio 2013

Windows

Visual Studio 2013
run BUILD_VS2013x64.bat

Usage

Set the member variables of class Prefilter use its Init().

the Input Lat-Long Environment Map. Like the helipad.hdr in data/image.
the shader programs directory
the result directory (Please make sure the output directory and Sub-Directories are created)
if the result is HDR (*.hdr) or LDR (*.png). Default is LDR(*.png).
if the coordinate is P20. Default is not P20.