MaterialX Support in Unreal Engine | Unreal Engine 5.8 Documentation

The MaterialX™ format is an open standard for representing rich material and look-development content in computer graphics, enabling its platform-independent description and exchange across applications and renderers. The project is now open-source, hosted by the Academy Software Foundation, and is ongoing development.

MaterialX allows the description of materials through graphs. Those graphs are fully built using MaterialX nodes describing a surface or a volume shader, combined with or without predefined distribution functions (BXDFs).

For a MaterialX file to be correctly supported in Unreal Engine, each file must have at least one surfacematerial or volumematerial node as en entry point, connected to either a predefined surfaceshader/volumeshader (BXDF) node or their generic counterpart surface/volume described in the MaterialX PBR Lib spec.

The different BXDF and nodes supported in Unreal Engine (UE) are described in the next sections.

Supported MaterialX version

Unreal Engine 5.8+ supports version 1.39.4 of the MaterialX specifications.

If you are using UE 5.7, the supported version is 1.39.3.

Support of MaterialX Nodes

Shading Model Examples

Autodesk Standard Surface and USD Preview Surface are supported with Substrate enabled or disable.

OpenPBR Surface is supported with Substrate enabled. However, if Substrate is disabled, the material functions of the StandardSurface are used.

glTF Surface is supported with Substrate enabled

Disney Principled BSDF is not supported.

MaterialX Physically Based Shading Nodes


BSDF Nodes	All BSDF nodes are implemented as pass-through. None of their inputs are connected.
EDF Nodes	With the exception of `uniform_edf`, EDF nodes are implemented as pass-through, and none of their inputs are connected.
VDF Nodes	All VDF nodes are supported.
Utility Nodes (labeled in the PBR lib)	Supported: `surface`, `displacement`, `roughness_anisotropy`, `roughness_dual`, `glossiness_anisotropy`, `blackbody`, and `artistic_ior`. Supported with Substrate enabled: `add`, `layer`, `mix` and `multiply`.

MaterialX NPR Shading Nodes

g18_rec709_to_lin_rec709, g22_rec709_to_lin_rec709, rec709_display_to_lin_rec709, acescg_to_lin_rec709, g22_ap1_to_lin_rec709, srgb_texture_to_lin_rec709, lin_adobergb_to_lin_rec709, adobergb_to_lin_rec709, srgb_displayp3_to_lin_rec709, lin_displayp3_to_lin_rec709 are supported.

The entire CM lib is supported.

MaterialX CM Nodes (Color Transforms)

viewdirection, facingratio and gooch_shade are supported.

MaterialX Standard Nodes

Standard Source Nodes

Types: All MaterialX types are supported except for:


matrix33 matrix44 integerarray floatarray	color3array color4array vector2array vector3array	vector4array stringarray geomnamearray

All other input/output nodes listed below are supported, unless specified otherwise.

Texture nodes:


image	filtertype (uniform string): unsupported layer (uniform string): unsupported framerange (uniform string): unsupported frameoffset (uniform string): unsupported frameendaction (uniform string): unsupported
tiledimage (nodegraph)	filtertype (uniform string): unsupported framerange (uniform string): unsupported frameoffset (uniform string): unsupported frameendaction (uniform string): unsupported
triplanarprojection (nodegraph)	filtertype (uniform string): unsupported layerx (uniform string): unsupported layery (uniform string): unsupported layerz (uniform string): unsupported framerange (uniform string): unsupported frameoffset (uniform string): unsupported frameendaction (uniform string): unsupported

Procedural nodes:


constant randomfloat randomcolor

Procedural2D nodes:


ramp ramp_gradient ramplr ramptb ramp4 splitlr splittb noise2d	cellnoise2d noise2d worleynoise2d jitter (float): unsupported style (integer): only the distance to the cell center is supported unifiednoise2d style (integer): only the distance to the cell center is supported

ramp
ramp_gradient
ramplr
ramptb
ramp4
splitlr
splittb
noise2d

cellnoise2d
noise2d
worleynoise2d
- jitter (float): unsupported
- style (integer): only the distance to the cell center is supported

unifiednoise2d
- style (integer): only the distance to the cell center is supported

Shape nodes (same nodegroup as Procedural2D):


checkerboard line circle cloverleaf hexagon	grid crosshatch tiledcircles tiledcloverleafs tiledhexagons

Procedural3D nodes:


noise3d cellnoise3d fractal3d	worleynoise3d jitter (float): unsupported style (integer): only the distance to the cell center is supported unifiednoise3d style (integer): only the distance to the cell center is supported

Math nodes:


add subtract multiply divide modulo fract invert absval floor ceil round power safepower sin cos	tan asin acos atan2 sqrt ln exp sign clamp min max normalize magnitude distance dotproduct	crossproduct transformpoint transformvector transformnormal transformmatrix (unsupported) transpose (unsupported) determinant (unsupported) invertmatrix (unsupported) creatematrix (unsupported) normalmap rotate2d rotate3d trianglewave reflect Refract

Geometric nodes:


position normal tangent texcoord geomcolor geompropvalue : unsupported, see Geompropvalue section for further explanation geompropvalueuniform : unsupported

Application nodes:


time frame : unsupported

Adjustment Nodes:


remap smoothstep luminance lumacoeffs only supported as a uniform value set in the details panel rgbtohsv hsvtorgb	contrast range hsvadjust saturate lumacoeffs only supported as a uniform value set in the details panel colorcorrect

Compositing nodes:


premult unpremult plus minus difference burn dodge screen overlay	disjointover in mask matte out over inside outside

Mix nodes:


All mix operations are supported except for displacementshader types

Conditional Nodes:


ifgreater ifgreatereq ifequal switch

Channel nodes:


convert : all conversion operations are supported, conversion to a surfaceshader creates a surfaceunlit material combine2 combine3 combine4	extract separate2 separate3 separate4

Convolution nodes:


blur Size is inconsistent when zooming in the viewport, as stated here. heighttonormal If the direct input is an image node, then the `NormalFromHeight`map material function is used. Otherwise, `HeightToNormalSmooth` material function is used. and or xor not

Organization nodes:


dot : not to be confused with `dotproduct`, this node acts as a noop.

Geompropvalues

For MaterialX standalone files, geompropvalues are not supported, unless if the type is a vector2 and the name is “st” following USD standard, then the node is converted to a texcoord node.

For MaterialX shader model embedded into USD, geompropvalues are linked to their USD counterpart “primvar” then are baked into texture and converted to an <image> node.

Standard Shader Nodes

All nodes are supported.

General nodes are used when the MaterialX file does not use one of the predefined BXDFs.