FPOM

FPOM Material Function

Inputs ​

UV ​

  • Type: UV
  • Default: Texture Coordinate of UV 0

Height Texture ​

  • Type: Texture Object (Required)
  • Note: For packed textures use the Height Texture Channel pin to set which channel holds the height texture

DDX ​

  • Type: float2
  • Default: ddx(UV)
  • Note: UV/DDX/DDY needs to be in sync. Use FPOM - UV Derivatives Debug Helper to debug if the projection looks wrong.

DDY ​

  • Type: float2
  • Default: ddy(UV)
  • Note: UV/DDX/DDY needs to be in sync. Use FPOM - UV Derivatives Debug Helper to debug if the projection looks wrong.

HeightRatio ​

  • Type: float
  • Default: 0.08

HeightCenter ​

  • Type: float
  • Default: 0.5
  • Options: Value from 0 to 1.

0 means the parallax starts at the surface and grows down, 1 means it starts at the surface and grows up. 0.5 means the growth is evenly split up and down.

Height Texture Channel ​

  • Type: float4
  • Default: 1,0,0,0

A channel mask (for example (1, 0, 0, 0) for red) selecting which channel of the heightmap texture holds the height data. Use this when the height is packed into a spare channel of an existing texture.

IsDecal ​

  • Type: Static Bool
  • Default: false

A static bool signaling if the function is used on a decal.

IsTiling ​

  • Type: Static Bool
  • Default: true

A static bool signaling if the height texture lookup should wrap or clamp. This value is always false if IsDecal is true.

Advanced ​

AxisU ​

AxisV ​

Outputs ​

UV/DDX/DDY

It's important to always hook up UV, DDX and DDY to ensure correct MIP sampling and Anisotropic Filtering

FPOM Material Function outputs

UV ​

  • Type: UV

DDX & DDY ​

  • Type: float2

Set MipValueMode on your Texture Samples to Derivative to enable the DDX/DDY inputs.

Optional ​

Pixel Depth Offset ​

  • Type: float
  • Note: Virtual Shadow Maps tends to self-shadow incorrectly when PDO is used.

Used to set PDO in the material output to make the surface look more 3D when intersecting with other objects.

WorldPosition Offset ​

  • Type: float3

Used to offset the world position when using FPOM on a RVT landscape.

SurfaceHeight ​

  • Type: float
  • Returns: 0 (bottom) to 1 (top)

Used to drive effects like fake AO in holes, water, etc.