1. pure c++ 11 implementation
2. left-hand z-up coordinate system
3. software-rasterizer
4. perspective-correct interpolation
5. z-buffer (reverse-z tech / z-test / z-write)
6. back culling / frustum culling / viewport clip
7. support wavefront .obj file
8. physically-based-shading with ibl
9. bilinear / trilinear texture sample
10. cube map sample
11. reinhard toon-mapping

generate ibl textures from an environment cubemap

1. indirect diffuse lighting
   • precompute indirect diffuse lighting stored in an irradiance map from a radiance map(environment cubemap)

   generate_irradiance_map("./resource/ibl_textures/env.png", "./resource/ibl_textures/irradiance.png");

2. indirect specular lighting
   • Split Sum Approximation, result in two part

   generate_prefilter_envmap("./resource/ibl_textures/env.png", "./resource/ibl_textures/prefilter");
   generate_BRDF_LUT("./resource/brdf_lut.png");

depth buffer

direct lighting only

with ibl

standard pbr with ibl

https://niepp.github.io/2016/05/20/PBR-notes.html