Fill Gradient Filter Component

Overview

This component can fill a UI element with a gradient of colors, with many options available.

WebGL Demo

Properties

Property	Type	Range	Default	Description
Shape
Shape	Enum		Horizontal	The shape of the gradient Graphic to fill. Options are: • None: The whole graphic is filled with the same gradient value. This can still animate using Offset or Scroll Speed. • Horizontal: Gradient starts at the left edge and ends at the right edge. • Vertical: Gradient starts at the top edge and ends at the bottom edge. • Diagonal: Gradient starts at the top-left corner and ends at the bottom-right corner. • Linear: Gradient follows the W3C definition for a linear gradient going in the direction specified by an angle. • Radial: Gradient starts from a specified point and radiates outwards. • Conic: Gradient starts from a specific point and sweeps outward based on the angular direction to that point.
Diagonal Flip	Bool		False	Flip the Diagonal gradient shape so the gradient starts at the bottom-left corner and ends at the top-right corner.
Angle	Float	[0..360]	0.0	Angle for the gradient in Linear mode. Angle starts at 0 which is from bottom to top and continues clockwise.
Radius	Float	[0..16]	0.5	Radius of the gradient in Radial mode.
CenterX/Y	Float	[-2..2]	0.0	Position of the gradient origin in Radial and Conic modes. 0.0 correspond to the center, -1.0 and 1.0 correspond to the edges of the rectangle. -2.0 and 2.0 correspond to double the distance from the edges.
Gradient
Gradient	Gradient		Default	The gradient to fill the Graphic with.
ColorSpace	Enum		Linear	The color-space used to blend the graphic colors in. Options are: • Linear: Convert colors to sRGB/linear before blending depending on the active colorspace in Unity. • Perceptual: Convert colors to OKLAB before blending. This is the most expensive option but gives the most natural results.
Lerp	Enum		Smooth	The interpolation type to use when sampling the gradient. Options are: • Step: No interpolation, just sample the nearest color stop. • Linear: Use linear interpolation. • Smooth: Use smoothstep interpolation.
Wrap	Enum		Clamp	How to tile the gradient when it is repeated. Options are: • Clamp: No tiling/repeating - the first and last colors extend to infinity. • Repeat: The gradient repeats when tiling. • Mirror: The gradient trepeats when tiling, but alternates direction after each tiling.
Dither	Float	[0..1]	0.125	Apply a random dithering when sampling the gradient which can help reduce banding, especially for dark gradients.
Area
Fill Space	Enum		Geometry	Options are: • Geometry: The gradient position is relative to the Graphic geometry. • Screen: The gradient position is relative to screen-space.
Transform
Repeat	Float	[0..100]	1.0	Scale the gradient to create a zoom in or zoom out effect.
Repeat Pivot	Float	[0..1]	0.5	The position on the gradient to use for scaling. Usual values of 0.0, 0.5 and 1.0 correspond to the scaling happening from the start, center and end of the gradient respectively.
Offset	Float	[-1..1]	0.0	Offset the gradient position.
Scroll Speed	Float	[-inf..inf]	0.0	Set an animation speed to offset the gradient.
Apply
Blend Mode	Enum		Blend	The blending mode to apply the gradient to the original Graphic. Options are: • Replace • Blend • Over • Under • Mask • Clear • Darken • Multiply • Color Burn • Linear Burn • Lighten • Screen • Color Dodge • Linear Dodge • Overlay • Soft Light • Hard Light • Vivid Light • Linear Light • Pin Light • Hard Mix • Difference • Exclusive • Subtract • Divide
Blend Mode Force Gamma Space	Bool		False	Whether to force blend operations in happen gamma-space to match the default in software such as PhotoShop. Otherwise blend operations happen in the active color-space.
Strength	Float	[0..1]	1.0	Strength of the effect.
Render Space	Enum		Canvas	Which coordinate system use when rendering this filter. Options are: • Canvas: Render the filter before any transforms (scale/rotation/translation etc) are applied. • Screen: Render the filter after transforms have been applied. Read more about this property here.

Usage

Add this component to any GameObject that contains a UI Graphic component (eg Text, Image, RawImage, etc). The object will now render with a shadow.

Usage with TextMeshPro

To use this filter effect with TextMeshPro use the Filter Stack (TextMeshPro) component.

Render Space

The RenderSpace property effectively controls whether the filter is rendered before or after the Transform is applied. There are two options:

• Canvas - This is the default mode for all filters. In this mode the filter is rendered to the Graphic before it is transformed into screen-space by the local Transform and by the Canvas. This means that any changes or animations to the transform (or it's parents) will not cause the filter to re-render (unless Canvas has pixel-perfect mode enabled), which is a performance benefit! This also means that when the Graphic is rotated, the filter will not be aware of this, so the filter will rotate as well.
• Screen - This was the default mode before version 1.8.0 was released. In this mode the filter is rendered to the Graphic after it is transformed into screne-space. This means that any changes or animations to the transform (or it's parents) will cause the filter to re-render which can become expensive. It has the advantage that it is possible to do some screen-aware options, such as clamping the filter to the edges of the screen, or extending an edge to the edge of the screen (for example in the Frame Filter component)

RenderSpace Rotation Example

In the above example you can see that Canvas RenderSpace renders the filters before the transforms are applied, so the drop shadow offset rotates with text and it is only rendered once which is good for performance. In the Screen RenderSpace the filter is rendered after the transform is applies, so the drop shadow offset is not affected by the transform (both situations are valid depending on the use-case), however each time the transform is updated the filter must render which is more expensive.

RenderSpace Scaling Example

Again in this example we can see that transform affects how often the filters are rendered. This example also shows how scaling looks in the two RenderSpace modes. In Canvas mode the scaling transform is applied after the filter, so the drop shadow distance appears to scale naturally. In the Screen mode, the scaling transform is applied before the filter, so the filter is using unscaled distance values so the drop shadow offset appears incorrect when scaled as the properties are in screen-space. This is also why the FilterStackTextMeshPro component has the Relative To Transform Scale property.

RenderSpace Canvas Example

In Unity it is common to use the Canvas Scaler component to allow the UI to scale to fit different device resolutions. UIFX supports this, but there are some subtle differences depending on the RenderSpace mode used. If you don't use the Canvas Scaler component, or your device resolution is the same as the Canvas Scaler reference resolution, then UIFX will render the filters at the same resolution in both Canvas and Screen RenderSpace modes. If however your device resolution is lower than the reference resolution (eg reference is 1080p but your device is 720p), then Canvas mode will still render the filter at the same resolution before, but Screen mode will render it at half the resolution. This means Screen mode will use less texture memory and will be faster. If your device resolkution is higher than the reference resolution (eg reference is 1080p but your device is 4K), then Canvas mode will still render the filter at the same resolution as before, but Screen mode will render at double the resolution. This means Screen mode will use double the texture memory compared to Canvas, however it also means that Screen will give slightly better quality results.

For example if you have reference resolution on the Canvas Scaler set to 1920x1080 and you have a UI text object is 400x200 on the screen with a filter applied to it:

• if your output resolution is 1920x1080, UIFX will render the filters at 400x200.
• if your output resolution is 3840x2160, UIFX will render the filter at 400x200 if it's in Canvas mode because the object is still 400x200 relative to the renference resolution - but in Screen mode it will render it at 800x400 because that is the size it will be on the screen.
• if your output resolution is 1280x720, UIFX will render the filter at 400x200 if it's in Canvas mode because the object is still 400x200 relative to the renference resolution - but in Screen mode it will render it at 266x133 because that is the size it will be on the screen.

Summary

A summary of the differences:

Feature	Canvas	Screen
Adjusting local/parent transforms causes filter re-render	No (unless Canvas has pixel-perfect mode enabled)	Yes
In WorldSpace Canvas adjusting camera transform causes filter re-render	No	Yes
Best performance when using ScrollRect	Yes	No
Filter offset/direction properties affected by rotation	Yes	No
Filter offset/direction properties affected by scale	Yes	No
Filter rendering resolution scales with screen resolution	No	Yes

In general, Canvas is usually the best option in terms of balance between performance, memory usage and functionlity. If you need higher quality rendering because you are targeting higher resolution devices than your reference resolution (on Canvas Scaler component), then use Screen mode. If you need the filter offset/direction properties to always run in screen-space (ie not be affected by rotation or other transforms), then use Screen mode.

Scripting

Namespace

The namespace

using ChocDino.UIFX;

Adding the Component

Add the component to your GameObject

// Add the component to your GameObject and set default properties
var fill = AddComponent<FillGradientFilter>();
fill.Shape = GradientShape.Horizontal;
fill.Gradient = ColorUtils.GetBuiltInGradient(BuiltInGradient.SoftRainbow);
fill.LerpMode = GradientLerp.Smooth;
fill.ColorSpace = GradientColorSpace.Linear;
fill.WrapMode = GradientWrap.Clamp;
fill.Dither = 0f;
fill.Repeat = 1f;
fill.RepeatCenter = 0.5f;
fill.Offset = 0f;
fill.ScrollSpeed = 0f;
fill.BlendMode = FillGradientBlendMode.AlphaBlend;

Set Linear Gradient Shape

Set linear gradient shape

// Set a linear gradient
var fill = GetComponent<FillGradientFilter>();
fill.Shape = GradientShape.Linear;
fill.LinearAngle = 45f;

Set Diagonal Gradient Shape

Set diagonal gradient shape

// Set a diagonal gradient
var fill = GetComponent<FillGradientFilter>();
fill.Shape = GradientShape.Diagonal;
fill.DiagonalFlip = false;

Set Radial Gradient Shape

Set radial gradient shape

// Set a radial gradient
var fill = GetComponent<FillGradientFilter>();
fill.Shape = GradientShape.Radial;
fill.CenterX = 0f;
fill.CenterY = 0f;
fill.Radius = 0.5f;

Set Conic Gradient Shape

Set conic gradient shape

// Set a conic gradient
var fill = GetComponent<FillGradientFilter>();
fill.Shape = GradientShape.Conic;
fill.CenterX = 0f;
fill.CenterY = 0f;
fill.Radius = 0.5f;

Set Gradient Colors

Set gradient colors

// Set custom gradient colors
var fill = GetComponent<FillGradientFilter>();
fill.Gradient = new Gradient()
{
  colorKeys = new GradientColorKey[]
  {
    new GradientColorKey(Color.red, 0f),
    new GradientColorKey(Color.white, 1f)
  }
};

Set Gradient Colors + Alpha

Set gradient colors + alpha

// Set custom gradient colors and alpha
var fill = GetComponent<FillGradientFilter>();
fill.Gradient = new Gradient()
{
  colorKeys = new GradientColorKey[]
  {
    new GradientColorKey(Color.red, 0f),
    new GradientColorKey(Color.white, 1f)
  },
  alphaKeys = new GradientAlphaKey[]
  {
    new GradientAlphaKey(1f, 0f),
    new GradientAlphaKey(0f, 1f),
  }
};

Modify Gradient Colors

Modify gradient colors

// Modify existing gradient colors (NOTE: Unity Gradients require making a copy of the keys)
var fill = GetComponent<FillGradientFilter>();
Gradient gradient = new Gradient();
var colorKeys = fill.Gradient.colorKeys;
var alphaKeys = fill.Gradient.alphaKeys;
colorKeys[0].color = new Color(Random.value, Random.value, Random.value, 1f);
fill.Gradient.SetKeys(colorKeys, alphaKeys);
fill.ForceUpdate();