Master material

Unless you pick your own master, Material Smith makes every material instance a child of M_Smith_Standard, a master material it creates in your project. It is an ordinary material asset built from standard material nodes, so your instances depend on it, not on the plugin.

Where and when it is created

• Folder: the Master Material Folder setting, /Game/MaterialSmith by default.
• When: the first time Create needs it, that is when the Master option is empty and the master does not exist yet. The preview only announces it: The master material M_Smith_Standard will be created in /Game/MaterialSmith. From Python, get_master_material() creates it too.
• Saving: the master and its default textures are saved right away, even when Save assets is off.
• Usage: the Skeletal Mesh and Instanced Static Meshes usage flags are turned on when it is created, so assigning instances to skeletal meshes or foliage doesn’t have to change the master later.

If an asset that is not a material already uses the name, Material Smith reports … exists but is not a material. Rename it or pick another Master Material Folder in Project Settings.

Parameters

The parameters are in numbered groups, so the material instance editor lists them in this order. Every static switch is off in the master; Material Smith turns on the ones a set needs in each instance.

01 Base Color

Parameter	Type	Default	Notes
Use Base Color Map	Static switch	Off	Off: the base color is Base Color Tint alone.
Base Color Map	Texture, Color sampler	Engine default texture	Multiplied by Base Color Tint.
Base Color Tint	Vector	White

02 Normal

Parameter	Type	Default	Notes
Use Normal Map	Static switch	Off	Off: a flat normal.
Normal Map	Texture, Normal sampler	Engine default normal map
Normal Strength	Scalar	1 (slider 0–2)	Scales the X and Y of the normal.

03 Roughness

Parameter	Type	Default	Notes
Use Roughness Map	Static switch	Off	Off: the Roughness value is used.
Roughness Map	Texture, Alpha sampler	T_Smith_Default_Mask	Red channel.
Roughness	Scalar	0.5	Used without a roughness map.
Roughness From Packed Map	Static switch	Off	Reads roughness from Packed Map instead of Roughness Map.
Invert Roughness (Glossiness)	Static switch	Off	Uses 1 − value, for glossiness or smoothness maps.
Roughness Min	Scalar	0	The map value is remapped to the range Roughness Min to Roughness Max.
Roughness Max	Scalar	1

04 Metallic

Parameter	Type	Default	Notes
Use Metallic Map	Static switch	Off	Off: the Metallic value is used.
Metallic Map	Texture, Alpha sampler	T_Smith_Default_Mask	Red channel.
Metallic	Scalar	0	Used without a metallic map.
Metallic From Packed Map	Static switch	Off	Reads metallic from Packed Map.
Metallic Intensity	Scalar	1	Multiplies the map value.

05 Ambient Occlusion

Parameter	Type	Default	Notes
Use Ambient Occlusion Map	Static switch	Off	Off: no occlusion (1).
Ambient Occlusion Map	Texture, Alpha sampler	T_Smith_Default_Mask	Red channel.
Ambient Occlusion From Packed Map	Static switch	Off	Reads occlusion from Packed Map.
Ambient Occlusion Strength	Scalar	1	Blends from no occlusion (0) to the full map value (1).

06 Packed Map

Parameter	Type	Default	Notes
Packed Map	Texture, Masks sampler	T_Smith_Default_Packed	One texture with several data maps (ORM, MRA …).
Packed AO Channel	Vector	(1, 0, 0, 0): red	Picks the channel that holds ambient occlusion.
Packed Roughness Channel	Vector	(0, 1, 0, 0): green	Picks the roughness channel.
Packed Metallic Channel	Vector	(0, 0, 1, 0): blue	Picks the metallic channel.
Packed Opacity Channel	Vector	(0, 0, 0, 1): alpha	Picks the opacity channel.

Each channel parameter has 1 in the channel to read and 0 in the others (red, green, blue, alpha). Material Smith sets them from the channel layout of the set’s packed texture, so ORM, MRA, RMA and ORD textures all work with the same master. Height is not read from packed textures: the blue channel of an ORD texture is not used.

07 Emissive

Parameter	Type	Default	Notes
Use Emissive Map	Static switch	Off	Off: no emission (black).
Emissive Map	Texture, Color sampler	Engine default texture	Multiplied by Emissive Color and Emissive Intensity.
Emissive Color	Vector	White
Emissive Intensity	Scalar	1 (slider 0–50)

08 Opacity

Parameter	Type	Default	Notes
Use Opacity Map	Static switch	Off	Off: fully opaque (1).
Opacity Map	Texture, Alpha sampler	T_Smith_Default_Mask	Red channel.
Opacity From Packed Map	Static switch	Off	Reads opacity from Packed Map.
Opacity From Base Color Alpha	Static switch	Off	Reads opacity from the alpha channel of Base Color Map. Takes effect while Use Opacity Map is on.
Opacity Strength	Scalar	1	Multiplies the opacity.

The result drives both the Opacity and the Opacity Mask input of the material. The master itself is opaque; Material Smith gives instances with an opacity map a Masked blend mode override.

09 Height

Parameter	Type	Default	Notes
Use Height Map (Parallax)	Static switch	Off	On: the texture coordinates of every map are offset with a Bump Offset node (reference plane 0.5).
Height Map	Texture, Alpha sampler	T_Smith_Default_Mask	Red channel.
Height Ratio	Scalar	0.02 (slider 0–0.2)	Strength of the parallax effect.

The height map is only used for parallax. It is assigned to every instance whose set has one, but the switch is turned on only with the Parallax for height maps option.

10 UV

Parameter	Type	Default	Notes
UV Tiling	Vector	(1, 1, 0, 0)	Red and green scale U and V.
UV Offset	Vector	(0, 0, 0, 0)	Red and green offset U and V.

All maps use the same texture coordinates: UV channel 0, multiplied by UV Tiling, plus UV Offset, and then the parallax offset if it is on.

How instances are set up

On every run, Material Smith sets the texture parameters of the detected maps and these switches in the instance:

Switch	On when
Use Base Color Map	The set has a base color map.
Use Normal Map	The set has a normal map.
Use Emissive Map	The set has an emissive map.
Use Height Map (Parallax)	The set has a height map and Parallax for height maps is on.
Use Roughness Map, Use Metallic Map, Use Ambient Occlusion Map, Use Opacity Map	The set has a separate map for it, or a packed texture with that channel.
Roughness From Packed Map, Metallic From Packed Map, Ambient Occlusion From Packed Map, Opacity From Packed Map	The set has no separate map for it, but its packed texture has the channel. The matching Packed … Channel parameter is set to that channel.
Invert Roughness (Glossiness)	The roughness map is marked as glossiness.

A separate map wins over a packed channel. Opacity From Base Color Alpha is never turned on by Material Smith; it is turned off when the set has an opacity map and otherwise left as it is.

Only the switches a set needs are on, so the instance compiles only the parts of the graph it uses.

Virtual texture variant

M_Smith_Standard_VT has the same graph and parameters with virtual texture samplers (Virtual Color, Virtual Normal, Virtual Masks, Virtual Alpha). It is created and used automatically when every map of a set (except Not Used textures) already streams as a virtual texture.

If only some maps of a set are virtual textures, the regular master is used and What will happen says Some maps are virtual textures and some are not. The regular master is used and virtual texture streaming is turned off for them. With Fix texture settings on, virtual texture streaming is then turned off for those textures. See Texture settings.

Default textures

Unreal checks the default texture of every texture parameter against its sampler type, even when an instance overrides the texture. A parameter whose default texture doesn’t fit breaks every instance of the material. Each parameter of the master therefore has a default texture that fits:

Sampler	Regular master	Virtual texture master
Color (Base Color Map, Emissive Map)	/Engine/EngineResources/DefaultTexture	T_Smith_Default_Color_VT
Normal (Normal Map)	/Engine/EngineMaterials/DefaultNormal	T_Smith_Default_Normal_VT
Masks (Packed Map)	T_Smith_Default_Packed	T_Smith_Default_Packed_VT
Alpha (Roughness, Metallic, Ambient Occlusion, Opacity and Height Map)	T_Smith_Default_Mask	T_Smith_Default_Mask_VT

The T_Smith_Default_* textures are created in the Textures subfolder of the master’s folder (/Game/MaterialSmith/Textures) when they don’t exist yet; existing ones are reused. If one of the engine textures doesn’t fit its sampler type, T_Smith_Default_Color or T_Smith_Default_Normal is created instead.

• T_Smith_Default_Packed: no occlusion, medium roughness, not metallic (red 255, green 128, blue 0), linear, Masks compression, no alpha.
• T_Smith_Default_Mask: white, linear, Alpha compression.
• The regular textures are 8 × 8 pixels; the virtual texture ones are 256 × 256 so they fill a whole virtual texture tile.

Edit, move or replace it

The master and its default textures are regular assets of your project. You can open, edit and version them like any other material.

• Editing: Material Smith never rebuilds an existing master. Keep the parameter names listed above: instances are filled by those names.
• Moving or renaming: Material Smith looks for M_Smith_Standard (and M_Smith_Standard_VT) by name in the Master Material Folder. After moving the master, set Master Material Folder to the new folder, otherwise the next run creates a new master in the old one. Default textures are looked for in the Textures subfolder of that folder.
• Picking it explicitly: a renamed copy of the master, or an instance of it, can be picked in Options > Master or Default Master. Material Smith recognizes it as a Material Smith master by its Packed AO Channel and Packed Roughness Channel parameters and fills it the same way.
• Starting fresh: set Master Material Folder to an empty folder. The next run creates a new master there, and instances updated by that run are re-parented to it.
• Replacing it: pick your own material in Options > Master, or set Default Master in Project Settings. See Custom master materials.

Note

Removing the plugin doesn’t affect the master or its instances. They are plain material assets and keep working without Material Smith.