Maybe so? I built the engine in the link you posted, and the version number was 4.22.0 after the build. There were ray tracing commands in the console, but I didn’t find any other relevant options. So what I need to build is the dev-rendering version? Not your link? Then in the dev-rendering branch, can I find the relevant functions of RTX and actually test them? Do you have to add RTX graphics card to 1809 system to run the test? I don’t know the main branch of the engine very well. Thank you for telling me that.