Using BumpOffset node to push-in rather than push-out?

From the documentation:

BumpOffset materials use a grayscale heightmap to give depth information. The brighter the value in the heightmap, the more ‘popped out’ the material will be; these areas will parallax (shift) as a camera moves across the surface. Darker areas in the heightmap are ‘further away’ and will shift the least.

I need a concave feature on an object, and pushing every part of the texture out but the concave feature in order to fake it isn’t an option. It seems that the default behavior of the node disallows it from being used to ‘indent’ areas, for example, by plugging in a minus value into the Height, but this is exactly what I need.

Is there any node that is designed to do this, or way to modify the BumpOffset node to do this?

Thanks!

Hi mechanicalsnowman -

You can achieve this effect by adjusting the reference plane settings in the BumpOffset node. By default it is set to 0.5 which means that within the 0 to 1 range of your heightmap input, values over 0.5 will be pushed up and values below will be sunk down. By adjust the reference plane to 1 than all values in the heightmap will be sunk down.

For further reference, Utility Expressions | Unreal Engine Documentation

Thank You

Eric Ketchum

Perfect, thank you Eric. I didn’t think to check the advanced BumpOffset node.