Exponential height fog on character BP

So i have a Exponential height fog on the character BP and in my game when it starts the floor is lava and will start to rise (Z Axis) and on that lava floor i have a box collision (300 z axis) and when the player enters the collision area i calculate how far from the collision box bottom the player currently is and then i Map Range Clamp it to

In Range A : 300.0

In Range B : 0.0

Out Range A : 0.02

Out Range B : 1.0

and then set the Fog Density to that.


If i stand still and let the box collision hit me (in a split second i see the fog change color but then just goes away) BUT if i start moving around the fog comes back again and then goes away when i stop moving.

Now if i disable the moving floor and then play again and this time i spawn beside the lava floor actor and move in with my character and stop moving it’s fine… the fog is present and working as it should and i can move about and everything is fine :S i dont understand it and have now “wasted” 3 hours trying to figure this out…


i stopped the Set Fog Density and set it manualy to 1.0 and starting playing and noooooo problems at all :S …