I would like to be able to use a Retro-Reflection Shading Model in a Material without having to modify engine low-level shader C++. Specifically, I am requesting a feature that will allow road signs and road lines and the like to reflect back toward a light source as they do in real life. I have searched this extensively and every solution I have found involves editing low-level shader code.
This feature should allow the user to use a single channel texture sample based input to set the reflection pattern and a three channel texture sample based input to set the reflected color and the ability to adjust the intensity and angle falloff based on the camera’s angle to the light source. The reflected values should also have the option of being added to the light propagation volume.
If, by some means, there is a way to achieve this effect without the need for a new feature and without modifying engine code, please point me in the right direction.