ShaderNode: MaterialX Nodes

[sunag]

Document with the purpose of comparing Three.js ShaderNode with MaterialX.

https://materialx.org/assets/MaterialX.v1.38.Spec.pdf

Geometric

Position

Supported	MaterialX	ShaderNode
✅	Position Model	positionGeometry
✅	Position Object	positionLocal
✅	Position World	positionWorld

Normal

Supported	MaterialX	ShaderNode
✅	Normal Model	normalGeometry
✅	Normal Object	normalLocal
✅	Normal World	normalWorld

Tangent

Supported	MaterialX	ShaderNode
✅	Tangent Model	tangentGeometry
✅	Tangent Object	tangentLocal
✅	Tangent World	tangentWorld

Bitangent

Supported	MaterialX	ShaderNode
✅	Bitangent Model	bitangentGeometry
✅	Bitangent Object	bitangentLocal
✅	Bitangent World	bitangentWorld

Texture coordinate

Supported	MaterialX	ShaderNode
✅	texcoord	uv( index )

Geometry attribute

Supported	MaterialX	ShaderNode
✅	geomcolor	attribute( 'color', 'vec3' )
✅	geompropvalue	attribute( value, type )

Application

Supported	MaterialX	ShaderNode
✅	frame	frameId
✅	time	timeLocal()
⬜️	updirection

Math

Supported	MaterialX	ShaderNode
✅	add	add( in1, in2 )
✅	subtract	sub( in1, in2 )
✅	multiply	mul( in1, in2 )
✅	divide	div( in1, in2 )
✅	modulo	mod( in1, in2 )
✅	absval	abs( in )
✅	sign	sign( in )
✅	floor	floor( in )
✅	ceil	ceil( in )
✅	round	round( in )
✅	power	pow( in1, in2 )
✅	sin	sin( in )
✅	cos	cos( in )
✅	tan	tan( in )
✅	asin	asin( in )
✅	acos	acos( in )
✅	atan2	atan2( in1, in2 )
✅	sqrt	sqrt( in )
⬜️	ln
✅	exp	exp( in )
✅	clamp	clamp( in, low = 0, high = 1 )
✅	min	min( in1, in2 )
✅	max	max( in1, in2 )
✅	normalize	normalize( in )
✅	magnitude	length( in )
✅	dotproduct	dot( in1, in2 )
✅	crossproduct	cross( in )
⬜️	transformpoint
⬜️	transformvector
⬜️	transformnormal
⬜️	transformmatrix	transformDirection( in, mat )
✅	normalmap	normalMap( in, ... )
⬜️	transpose
⬜️	determinant
⬜️	invertmatrix
✅	rotate2d	rotateUV( in, degToRad( amount ) )
⬜️	rotate3d
⬜️	arrayappend
⬜️	dot

Adjustment

Supported	MaterialX	ShaderNode
✅	remap	remap( in, inlow, inHigh, outLow, outHigh )
✅	smoothstep	smoothstep( in, low, high )
⬜️	curveadjust
⬜️	curvelookup
✅	luminance	luminance( in, lumacoeffs = lumeCoeffs )
✅	rgbtohsv	mx_rgbtohsv( rgb )
✅	hsvtorgb	mx_hsvtorgb( hsv )

Compositing

Premult

Supported	MaterialX	ShaderNode
⬜️	premult
⬜️	unpremult

Blend

Supported	MaterialX	ShaderNode
✅	plus	add( b, f )
✅	minus	sub( b, f )
✅	difference	difference( b, f )
✅	burn	burn( b, f )
✅	dodge	dodge( b, f )
✅	overlay	overlay( b, f )

Merge

Supported	MaterialX	ShaderNode
⬜️	disjointover
⬜️	in
⬜️	mask
⬜️	matte
⬜️	out
⬜️	over

Masking

Supported	MaterialX	ShaderNode
⬜️	inside
⬜️	outside

Mix

Supported	MaterialX	ShaderNode
✅	mix	mix( x, y, a )

Conditional

Supported	MaterialX	ShaderNode
✅	ifgreater	cond( greaterThan( in1, in2 ), value1, value2 )
✅	ifgreatereq	cond( greaterThanEqual( in1, in2 ), value1, value2 )
✅	equal	cond( equal( in1, in2 ), value1, value2 )
⬜️	switch

Channel

Supported	MaterialX	ShaderNode
✅	convert	vec*( in ) or type*( in )
✅	swizzle	node.xyzw or node.rgba
✅	combine2	vec2( in1, in2 )
✅	combine3	vec3( in1, in2, in3 )
✅	combine4	vec4( in1, in2, in3, in4 )

Convolution

Supported	MaterialX	ShaderNode
⬜️	blur
⬜️	heighttonormal

Procedural

Supported	MaterialX	ShaderNode
✅	constant	float( value ), vec2( value ), vec3( value ), ...
✅	ramplr	mx_ramplr( valuel, valuer, texcoord )
✅	ramptb	mx_ramptb( valuet, valueb, texcoord )
✅	splitlr	mx_splitlr( valuel, valuer, center, texcoord )
✅	splittb	mx_splittb( valuet, valueb, texcoord )
✅	noise2d	mx_noise_float( vec2( texcoord ), amplitude = 1, pivot = 0 )
✅	noise3d	mx_noise_float( vec3( texcoord ), amplitude = 1, pivot = 0 )
✅	fractal3d	mx_fractal_noise_float( position, octaves = 3, lacunarity = 2, diminish = .5, amplitude = 1 )
✅	cellnoise2d	mx_cell_noise_float( vec2( texcoord ) )
✅	cellnoise3d	mx_cell_noise_float( vec3( texcoord ) )
✅	worleynoise2d	mx_worley_noise_float(.vec2( texcoord ), jitter = 1 )
✅	worleynoise3d	mx_worley_noise_float(.vec3( texcoord ), jitter = 1 )

Global

Supported	MaterialX	ShaderNode
⬜️	ambientocclusion

Color Management

Supported	MaterialX	ShaderNode
✅ (Partial)	colorspace	colorspace()

Supplemental

Supported	MaterialX	ShaderNode
⬜️	tiledimage
✅	triplanarprojection	triplanarTextures( filex, filey, filez )
⬜️	ramp4
⬜️	place2d
⬜️	safepower
✅	contrast	add( mul( in, amount ), pivot )
⬜️	range
⬜️	hsvadjust
✅	saturate	saturation( in, amount )
✅	extract	node[ 0 ], node[ 1 ], .. or element( node, index )
✅	separate2	node.x, node.y
✅	separate3	node.x, node.y, node.z
✅	separate4	node.x, node.y, node.z, node.w

[DennisSmolek]

There’s 3 other sets of nodes to consider that are already in the standards, and deployed.

Material X Physical Based Shading Nodes

I think this has some crossover with the full spec but I haven’t checked yet. I just immediately noticed some missing ones like lights.

MaterialX Supplemental Nodes

These are listed as not core/critical but are supported and there are some useful ones, triplanarProjection for one..

MaterialX Lama Layering / bxdf

These are apart of the Pixar standard and are actually in the standard package/shaderGen now, although not as clearly documented…

The layering is a bit confusing and I haven’t tried the webViewer on a model that utilizes it (all Pixar USDs are MASSIVE)

I’m not advocating the support or necessity of any nodes at this point, but wanted to make sure the list was complete and accurate..

Here is the internal library ref/list

[sunag]

@DennisSmolek Thank you for the informations!

[hybridherbst]

There's new NPR (non-photorealistic rendering) nodes in MaterialX 1.39, which have often been requested and allow to create effects like fresnel: https://github.com/AcademySoftwareFoundation/MaterialX/blob/main/documents/Specification/MaterialX.NPRSpec.md

The current set includes the following nodes:

viewdirection 
facingratio
gooch_shade