Material Basics in Unreal

Material Basics

• Textures Sampler Source: Shared allows the use of more than 16 texture samplers.
• Texture Objects - Stores a reference to a texture but does not actually sample it.
• Texture Sampler: Gets a references to a texture and samples it based on UV coordinates.
• Const Coordinate - Same as setting the Coordinate Index on a Texture Coordinate node.
• Sampler Type - Differs depending on the texture compression type. Usually set automatically but can be overwritten.
• Fully Rough - Ignores roughness property and sets it to be always rough. Optimizes the number of instructions and sampler count.
• Normal Curvature to Roughness - Good for metallic & clear coat materials. Reduces roughness based on screen space normal changes.
• IsSky - Meshes with a material that has this enabled will not receive any skylight contribution. Height & Volumetric fog will remain.
• SSR - Enables SSR on a per material basis.
• Contact Shadows - Allows for contact shadows on translucent objects.
• Compute Fog Per Pixel - Reducing artefacting on material surfaces that intersect with fog elements. A bit more expensive.
• Render After DOF - Allows for translucency to be rendered in a separate pass. Requires Separate Translucency Enabled in project Settings.
• Tessellation Mode - Two different methods of calculating tessellation.
• Flat Tessellation - Splits up the triangles but doesn’t do anything else to it.
• PN Triangles - Splits & smooths the objects. Objects in question required smoothing groups.

1. Common Nodes

• 3 Vector - 3 channel node without alpha.
• 4 Vector - 3 channel node with a separate alpha channel.
• Lerp - Linear Interpolate used for blending two inputs by an alpha.
• Divide - When applied to numbers divides them. When applied to textures Darkens them.
• Add - When applied to numbers adds them. When applied to textures Lightens them. Adding a value to a texture coordinate node has the ability to shift the uv’s in x or y.
• Multiple - When applied to numbers multiplies them. When applied to textures Multiplies them.
• SetMaterialAttributes - Similar to MakeMaterialAttrs but it lets you choose specific attrs.
• WorldAlignedTexture - Projects textures in WorldSpace rather than relying on UV’s
• Static Bool - Good to hide/show features from material instances
• Flatten Normal - Flattens a normal input

2. Material Basics

Textures Sampler Source: Shared allows the use of more than 16 texture samplers.

Texture Objects - Stores a reference to a texture but does not actually sample it.

Texture Sampler: Gets a references to a texture and samples it based on UV coordinates.

Const Coordinate - Same as setting the Coordinate Index on a Texture Coordinate node.

Sampler Type - Differs depending on the texture compression type. Usually set automatically but can be overwritten.

Fully Rough - Ignores roughness property and sets it to be always rough. Optimizes the number of instructions and sampler count.

Normal Curvature to Roughness - Good for metallic & clear coat materials. Reduces roughness based on screen space normal changes.

IsSky - Meshes with a material that has this enabled will not receive any skylight contribution. Height & Volumetric fog will remain.

SSR - Enables SSR on a per material basis.

Contact Shadows - Allows for contact shadows on translucent objects.

Compute Fog Per Pixel - Reducing artefacting on material surfaces that intersect with fog elements. A bit more expensive.

Render After DOF - Allows for translucency to be rendered in a separate pass. Requires Separate Translucency Enabled in project Settings.

Tessellation Mode - Two different methods of calculating tessellation.

Flat Tessellation - Splits up the triangles but doesn’t do anything else to it.

PN Triangles - Splits & smooths the objects. Objects in question required smoothing groups.

3. Material Types

Default Lit Translucent Unlit Masked TwoSided Foliage Thin Translucency Single Layer Water

4. Organizing your Material Graphs

• Use sort priorities
• Break large common tasks into material functions
• Comment your graph node
• Colour code your comments
• Use the reroute nodes
• Use material parameter collections
• Use separators