Project training of Software College of Shandong University rendering engine system radiation pre calculation (IX)

Preface

This project hopes to implement a basic renderer , At the same time, it can support the use of precomputing . This article mainly explains the PathTracer Specific code .
Project address

One 、 Basic logic

The path tracking process doesn't make much difference , The specific change is that the results are not displayed on the screen , Instead, save it to the picture . We opened up a space for the picture in advance , After that, make a good correspondence between the picture and the direction of local space , That is, each frame corresponds to a pixel of the picture , Then save the result of one frame directly into the picture .

Because what we store is the result of one frame , So before accumulate It doesn't work anymore , We use multiple samples within a pixel , Try to make the result converge in one frame .

about ToneMapping, Because we don't want to get a final color on the screen , But to get the incident light distribution for a certain point , Therefore, there is no need for tone mapping , If it does , On the contrary, you will get the wrong result when restoring .

Two 、 Main function code

1、 Trace the color

2、 Save color to cubemap

Normalize the solid angle before saving

summary

It mainly shows the PathTracer The main code of function realization .