I am running UE4.6.1. I have made some changes to the engine and the PostprocessTonemap.usf shader file. However when starting the editor, I always have to modify the shader and recompile it to see the changes I’ve made. I have tried deleting everything in the “DerivedDataCache” folder. After clearing the folder, the first time running the editor showed the expected changes. Anytime after the initial run, I’d have to go and modify the shader (eg. add a space), save, and recompile using the command line in the editor.
It just doesn’t make sense. This was working fine on version 4.4, so I am not sure why I am seeing this problem now…
I have fixed the issue. You have to make sure you serialize the parameters using the Serialize function. I was setting shader values but not serializing.