Rasagar/Library/PackageCache/com.unity.shadergraph/Documentation~/Hue-Node.md
2024-08-26 23:07:20 +03:00

2.4 KiB

Hue Node

Description

Offsets the hue of input In by the amount of input Offset. The unit of the offset can be set with the parameter Range. Offset in Degrees is in the range -180 to 180. In Radians it is -Pi to Pi.

Ports

Name Direction Type Binding Description
In Input Vector 3 None Input value
Offset Input Float None Amount to offset hue
Out Output Vector 3 None Output value

Controls

Name Type Options Description
Range Dropdown Degrees, Radians The unit used for the input Offset

Generated Code Example

The following example code represents one possible outcome of this node per Base mode.

Degrees

void Unity_Hue_Degrees_float(float3 In, float Offset, out float3 Out)
{
    float4 K = float4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
    float4 P = lerp(float4(In.bg, K.wz), float4(In.gb, K.xy), step(In.b, In.g));
    float4 Q = lerp(float4(P.xyw, In.r), float4(In.r, P.yzx), step(P.x, In.r));
    float D = Q.x - min(Q.w, Q.y);
    float E = 1e-10;
    float3 hsv = float3(abs(Q.z + (Q.w - Q.y)/(6.0 * D + E)), D / (Q.x + E), Q.x);

    float hue = hsv.x + Offset / 360;
    hsv.x = (hue < 0)
            ? hue + 1
            : (hue > 1)
                ? hue - 1
                : hue;

    float4 K2 = float4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
    float3 P2 = abs(frac(hsv.xxx + K2.xyz) * 6.0 - K2.www);
    Out = hsv.z * lerp(K2.xxx, saturate(P2 - K2.xxx), hsv.y);
}

Radians

void Unity_Hue_Radians_float(float3 In, float Offset, out float3 Out)
{
    float4 K = float4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
    float4 P = lerp(float4(In.bg, K.wz), float4(In.gb, K.xy), step(In.b, In.g));
    float4 Q = lerp(float4(P.xyw, In.r), float4(In.r, P.yzx), step(P.x, In.r));
    float D = Q.x - min(Q.w, Q.y);
    float E = 1e-10;
    float3 hsv = float3(abs(Q.z + (Q.w - Q.y)/(6.0 * D + E)), D / (Q.x + E), Q.x);

    float hue = hsv.x + Offset;
    hsv.x = (hue < 0)
            ? hue + 1
            : (hue > 1)
                ? hue - 1
                : hue;

    // HSV to RGB
    float4 K2 = float4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
    float3 P2 = abs(frac(hsv.xxx + K2.xyz) * 6.0 - K2.www);
    Out = hsv.z * lerp(K2.xxx, saturate(P2 - K2.xxx), hsv.y);
}