I find it is hard to adds PostProcessing codes without changing Engine Source Codes

I find it is hard to adds PostProcessing codes without changing Engine Source Codes.

Any suggestions for adding post processing C++ codes except changing Engine Source Codes?

Thank you.

I have seen the roadmap that ability to add postprocess effects. Waiting for the newer UE4 Engine Release.

https://trello.com/c/xT6CTqBj/205-better-extendability-via-plugins