Propeller System

I was asked to create a realistic propeller system for an upcoming simulation game called Combat Pilot. Their goal was a highly realistic result, with reflection, volumetric feel from all sides, seamless transition between speed states, and pitch control of the blades.

My solution was a trick I learned from a blog post, which actually present all the issues I had : the lack of volumetric feel of cheating with planes, motion blur of rotary objects : http://nothkedev.blogspot.com/2018/10/correct-motion-blur-for-fast-rotating.html.

I created a curve table for the different speed states that gave back various outputs like how blurred are the look, opacity control, rotation speed, how wide would be blurred parts, etc. The Blueprint got the speed value and sent the parameters to a single Niagara system, that controlled the whole look.

The end result was real-life looking and felt natural. Although the translucent blades could cause heavy overdraw, but luckily only from the sides, where the fillrate is low, and when the fillrate is high (eg from the cockpit) , the overdraw is manageable. I stress tested the system with 40 indiviual propellers on a single screen and I could not profile great dips in performance. There is definitely room for improvement but my part had been ended, so maybe in the future.