| Material Domain |
This setting allows you to designate how this Material is going to be used. Certain Material uses (such as decals) require additional instructions for the rendering engine to consider. Because of this, it is important to designate the Material as being used for those cases. Material Domain includes the following options:
| Domain |
Description |
| Surface |
This setting defines the Material as something that will be used on an object's surface; think metal, plastic, skin, or any physical surface. As such this is the setting that you will use most of the time. |
| Deferred Decal |
When making a Decal Material, you will use this setting. |
| Light Function |
Used when creating a Material for use with a Light Function. |
| Volume |
Used when describing the material's attributes as a 3D volume. |
| Post Process |
Used if the Material will be used as a Post Process Material. |
| User Interface |
Used when this material is used for UMG or Slate user interfaces. |
| Virtual Texture |
Used when making a Runtime Virtual Texture. |
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| Blend Mode |
Blend Modes describe how the output of the current Material will blend over what is already being drawn in the background. Put more technically, it allows you to control how the engine will combine this Material (Source color) with what is already in the frame buffer (Destination color) when rendered. The available blending modes are:
| Mode |
Description |
| BLEND_Opaque |
Final color = Source color. This means that the Material will draw on top of the background. This blend mode is compatible with lighting. |
| BLEND_Masked |
Final color = Source color if OpacityMask > OpacityMaskClipValue, otherwise the pixel is discarded. This blend mode is compatible with lighting. |
| BLEND_Translucent |
Final color = Source color Opacity + Dest color (1 - Opacity). This blend mode is NOT compatible with dynamic lighting. |
| BLEND_Additive |
Final color = Source color + Dest color. This blend mode is NOT compatible with dynamic lighting. |
| BLEND_Modulate |
Final color = Source color x Dest color. This blend mode is NOT compatible with dynamic lighting, or fog, unless this is a decal material. |
For more information on these Blend Modes, please see the Blend Modes documentation.
|
| Decal Blend Mode |
As the name suggests, this defines the Blend Mode that will be used when the Material Domain property is set to Deferred Decal and cannot be changed until the Material Domain is set accordingly. It contains different Blend Modes than those available to surfaces.
| Mode |
Description |
| Translucent |
This will cause the decal to blend Base Color, Metallic, Specular, Roughness, Emissive color, Opacity, and Normal. With this you can blend in an entirely separate material, such as a wavy water puddle, complete with normal map-based muddy building around it. |
| Stain |
Only blends Base Color and Opacity. Useful for decals that only change color, such as dry spray paint on a wall. |
| Normal |
Only blends Normal and Opacity. This is useful for adding cracks to a surface. |
| Emissive |
Only blends the Emissive and Opacity channels. Nice for making things glow that were not originally. |
| DBuffer Translucent Color, Normal, Roughness |
Put into the DBuffer to work for baked lighting as well. |
| DBuffer Translucent Color |
Put into the DBuffer to work for baked lighting as well. |
| DBuffer Translucent Color, Normal |
Put into the DBuffer to work for baked lighting as well. |
| DBuffer Translucent Color, Roughness |
Put into the DBuffer to work for baked lighting as well. |
| DBuffer Translucent Normal |
Put into the DBuffer to work for baked lighting as well. |
| DBuffer Translucent Normal, Roughness |
Put into the DBuffer to work for baked lighting as well. |
| DBuffer Translucent Roughness |
Put into the DBuffer to work for baked lighting as well. |
| Volumetric Distance Function (experimental) |
Outputs a signed distance in Opacity depending on the LightVector. This can be costly and has no shadow casting but does receive shadows. Also, no per pixel normal, nor quality settings are set up. |
| AlphaComposite (Premultiplied Alpha) |
Blends the material with existing scene color. Decal color is already pre-multiplied by the alpha. |
| Ambient Occlusion |
Applies ambient occlusion to the decal to simulate self-shadowing that happens within the crevices of a surface. |
|
| Shading Model |
Shading models determine how material inputs (e.g. Emissive, Diffuse, Specular, Normal) are combined to make the final color.
| Model |
Description |
| Unlit |
The Material is defined by the Emissive and Opacity inputs only. It does not respond to light. |
| Default Lit |
The default shading model. Perfect for most solid objects. |
| Subsurface |
Used for subsurface scattering materials, such as wax and ice. Activates the Subsurface Color input. |
| Preintegrated Skin |
Used for materials similar to human skin. Activates the Subsurface Color input. |
| Clear Coat |
Used for materials that have a translucent coating on top like clear coat car paint or lacquer. Activates the Clear Coat and Clear Coat Roughness inputs. |
| Subsurface Profile |
Used for materials similar to human skin. Requires the use of a Subsurface Profile in order to work correctly. |
| Two Sided Foliage |
Used for materials that create natural looking foliage with accurate lighting and light transmission through surfaces, such as throug leaves on a tree. |
| Hair |
Used for materials that create realistic looking hair that accurately lights the hair shafts and handles specular highlight. |
| Cloth |
Used for materials that need to create realistic looking cloth and fuzz along its surface. |
| Eye |
Used for materials that recreate the natural look of humanoid eyes. |
| Single Layer Water |
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| Thin Translucent |
Used for materials that create physically based glass, such as colored or tinted glass. It properly handles white specular from light sources and tinted background objects. |
| From Material Expression |
Used for handling multiple shading models in a single material. |
For more information on these Shading Models, please see the Shading Model documentation.
|
| Two Sided |
The normal will be flipped on back faces, which means lighting will be calculated for both the front faces and the back faces. This is commonly used on foliage to keep from having to double up the number of polygons. Two Sided does not work correctly with static lighting, since the mesh still uses only a single UV set for light mapping. As a result, two sided materials with static lighting will be shaded the same on both sides. |
| Use Material Attributes |
This checkbox will cause the Material's primary node to be condensed down to a single input labeled "Material Attributes." This is useful when you need to blend in multiple Materials using Layered Materials, or when defining multiple Material types using a Make Material Attributes expression node. See the Layered Materials documentation for more information. |
| Cast Ray Traced Shadows |
This checkbox enables ray traced shadows to be used with this material when Ray Tracing features are enabled in the Project Settings. |
| Subsurface Profile |
This will allow you to change what Subsurface Profile is used in the Material. |
| Advanced Properties |
|
| Decal Response |
This defines how the Material reacts on DBuffer decals(Affects look, performance, and texture/sample usage). Non DBuffer Decals can be disabled on the primitive(e.g. static mesh) |
| Cast Dynamic Shadow as Masked |
Whether the material should cast shadows as masked even though it has a translucent blend mode set. |
| Opacity Mask Clip Value |
This is the reference value which the OpacityMask input of masked materials will clip against per-pixel. Any value higher than OpacityMaskClipValue will pass and the pixel will be drawn (opaque), any value lower will fail and the pixel will be discarded (transparent). |
| Dithered LOD Transition |
Whether meshes rendered with this material should support dithered LOD transitions. |
| Dither Opacity Mask |
When combined with Temporal Anti-Aliasing, this can be used as a form of limited translucency which supports all lighting features. |
| Allow Negative Emissive Color |
Whether the material should allow outputting negative emissive color values. This is only allowed on Unlit materials. |
| Num Customized UVs |
This sets the number of Customized UV inputs to display. Unconnected customized UV inputs will just pass through the vertex UVs. |
| Generate Spherical Particle Normal's |
This produces surface normal's that remain spherical as you rotate around a Particle System that uses this Material. This is useful for volumetric Particle Systems, since the sprites always rotate to face the camera. With this option, they will have a more spherical volume appearance. |
| Tangent Space Normal |
Tangent space normal's are calculated from the surface of the object, with the Z-Axis (blue) always pointing directly away from the surface. World space normal's use the world coordinate system to calculate pixel angle, ignoring the surface's original orientation. Tangent space calculations are a bit more costly in terms of performance, but are generally more convenient, as these are usually the types of normal maps you can create in 2D applications such as Photoshop. Visually, tangent-space normal maps tend to look primarily blue-ish, while world-space maps are more vividly rainbow-colored. |
| Emissive(Dynamic Area Light) |
If enabled, the Material's Emissive color is injected into the Light Propagation Volume. |
| Block Global Illumination |
If enabled, the Material's opacity defines how much global illumination is blocked when using Light Propagation Volume features. |
| Fully Rough |
Forces the material to be completely rough. This saves a number of material instructions and one sampler. |
| Normal Curvature to Roughness |
Reduces the roughness based on screen space normal changes. |
| Wire Frame |
Enables a wire frame view of the mesh the Material is applied to. |
| Is Sky |
Unlit and Opaque blend modes used in materials can be used as a Sky Material on a sky dome mesh. When enabled, these meshes will not recieve any contribution from the aerial perspective. Height and Volumetric Fog effects will still be applied. |
| Asset User Data |
An array of user data stored with the asset. |