HDRI

HDRI uses floating-point to directly store the brightness information of each pixel location, bright places can be very bright, dark places can be very dark, and can be used directly as a light source.

The LDR images are mostly 8bit quantized, and the brightness is compressed to 0-255, so the real brightness of a certain pixel position cannot be known. Forcibly adjusting the brightness will cause obvious quantization noise, so it cannot be directly used for lighting.

During the whole process, the only problem was that the projection material cannot be used, which I could not solve, so I finally used Arnold to make another projection material.

Self-made Projection material:

This is my final effect: