diff --git a/types/three/examples/jsm/nodes/Nodes.d.ts b/types/three/examples/jsm/nodes/Nodes.d.ts
index d194de5ab..6ccf790b4 100644
--- a/types/three/examples/jsm/nodes/Nodes.d.ts
+++ b/types/three/examples/jsm/nodes/Nodes.d.ts
@@ -7,7 +7,7 @@ import ConstNode from './core/ConstNode';
 import ContextNode from './core/ContextNode';
 import ExpressionNode from './core/ExpressionNode';
 import FunctionCallNode from './core/FunctionCallNode';
-import FunctionNode from './core/FunctionNode';
+import FunctionNode, { FunctionNodeParameters } from './core/FunctionNode';
 import InstanceIndexNode from './core/InstanceIndexNode';
 import Node from './core/Node';
 import NodeAttribute from './core/NodeAttribute';
@@ -118,6 +118,7 @@ export {
     ExpressionNode,
     FunctionCallNode,
     FunctionNode,
+    FunctionNodeParameters,
     InstanceIndexNode,
     Node,
     NodeAttribute,
diff --git a/types/three/examples/jsm/nodes/core/CodeNode.d.ts b/types/three/examples/jsm/nodes/core/CodeNode.d.ts
index c24c0e805..7ac8b841b 100644
--- a/types/three/examples/jsm/nodes/core/CodeNode.d.ts
+++ b/types/three/examples/jsm/nodes/core/CodeNode.d.ts
@@ -3,13 +3,13 @@ import Node from './Node';
 import NodeBuilder from './NodeBuilder';
 
 export interface CodeNodeInclude {
-    build(): void;
+    build(builder: NodeBuilder): void;
 }
 
 export default class CodeNode extends Node {
     isCodeNode: true;
     code: string;
-    constructor(code: string, nodeType?: NodeTypeOption);
+    constructor(code?: string, includes?: CodeNodeInclude[]);
 
     setIncludes(includes: CodeNodeInclude[]): this;
     getIncludes(builder: NodeBuilder): CodeNodeInclude[];
diff --git a/types/three/examples/jsm/nodes/core/FunctionCallNode.d.ts b/types/three/examples/jsm/nodes/core/FunctionCallNode.d.ts
index 4712e2dc9..6e62e28aa 100644
--- a/types/three/examples/jsm/nodes/core/FunctionCallNode.d.ts
+++ b/types/three/examples/jsm/nodes/core/FunctionCallNode.d.ts
@@ -2,12 +2,12 @@ import FunctionNode from './FunctionNode';
 import TempNode from './TempNode';
 import Node from './Node';
 
-export default class FunctionCallNode extends TempNode {
-    functionNode: FunctionNode;
+export default class FunctionCallNode<P extends Node[] | { [name: string]: Node }> extends TempNode {
+    functionNode: FunctionNode<P>;
     parameters: { [name: string]: Node };
 
-    constructor(functionNode?: FunctionNode, parameters?: { [name: string]: Node });
+    constructor(functionNode?: FunctionNode<P>, parameters?: P);
 
-    setParameters(parameters: { [name: string]: Node }): this;
-    getParameters(): { [name: string]: Node };
+    setParameters(parameters: P): this;
+    getParameters(): P;
 }
diff --git a/types/three/examples/jsm/nodes/core/FunctionNode.d.ts b/types/three/examples/jsm/nodes/core/FunctionNode.d.ts
index 33ed738e2..e312df8af 100644
--- a/types/three/examples/jsm/nodes/core/FunctionNode.d.ts
+++ b/types/three/examples/jsm/nodes/core/FunctionNode.d.ts
@@ -1,15 +1,17 @@
-import CodeNode from './CodeNode';
+import CodeNode, { CodeNodeInclude } from './CodeNode';
 import FunctionCallNode from './FunctionCallNode';
 import NodeBuilder from './NodeBuilder';
 import NodeFunction from './NodeFunction';
 import NodeFunctionInput from './NodeFunctionInput';
 import Node from './Node';
 
-export default class FunctionNode extends CodeNode {
+export type FunctionNodeParameters = Node[] | { [name: string]: Node };
+
+export default class FunctionNode<P extends Node[] | { [name: string]: Node }> extends CodeNode {
     keywords: { [key: string]: Node };
-    constructor(code?: string);
+    constructor(code?: string, includes?: CodeNodeInclude[]);
 
     getInputs(builder: NodeBuilder): NodeFunctionInput[];
     getNodeFunction(builder: NodeBuilder): NodeFunction;
-    call(parameters: { [name: string]: Node }): FunctionCallNode;
+    call(parameters: P): FunctionCallNode<P>;
 }
diff --git a/types/three/examples/jsm/nodes/materialx/functions/lib/mx_hsv.d.ts b/types/three/examples/jsm/nodes/materialx/functions/lib/mx_hsv.d.ts
new file mode 100644
index 000000000..5dd4b8dab
--- /dev/null
+++ b/types/three/examples/jsm/nodes/materialx/functions/lib/mx_hsv.d.ts
@@ -0,0 +1,4 @@
+import { FnParameters, Node, Swizzable } from '../../../Nodes';
+
+export function mx_hsvtorgb(...params: FnParameters<[Node]>): Swizzable;
+export function mx_rgbtohsv(...params: FnParameters<[Node]>): Swizzable;
diff --git a/types/three/examples/jsm/nodes/materialx/functions/lib/mx_noise.d.ts b/types/three/examples/jsm/nodes/materialx/functions/lib/mx_noise.d.ts
new file mode 100644
index 000000000..28187b33b
--- /dev/null
+++ b/types/three/examples/jsm/nodes/materialx/functions/lib/mx_noise.d.ts
@@ -0,0 +1,6 @@
+import { FnParameters, Node, Swizzable } from '../../../Nodes';
+
+export function mx_perlin_noise_float(...params: FnParameters<[Node]>): Swizzable;
+export function mx_cell_noise_float(...params: FnParameters<[Node]>): Swizzable;
+export function mx_worley_noise_float(...params: FnParameters<[Node]>): Swizzable;
+export function mx_fractal_noise_float(...params: FnParameters<[Node, Node, Node, Node]>): Swizzable;
diff --git a/types/three/examples/jsm/nodes/shadernode/ShaderNode.d.ts b/types/three/examples/jsm/nodes/shadernode/ShaderNode.d.ts
index 900a3b3e5..849744a47 100644
--- a/types/three/examples/jsm/nodes/shadernode/ShaderNode.d.ts
+++ b/types/three/examples/jsm/nodes/shadernode/ShaderNode.d.ts
@@ -7,17 +7,19 @@ export type Swizzable<T extends Node = Node> = T &
     };
 
 /** anything that can be passed to {@link nodeObject} and returns a proxy */
-export type NodeRepresentation = number | boolean | Node | Swizzable;
+export type NodeRepresentation<T extends Node = Node> = number | boolean | Node | Swizzable<T>;
 
 /** anything that can be passed to {@link nodeObject} */
 export type NodeObjectOption = NodeRepresentation | string;
 
-// same logic as in ShaderNodeObject
+// same logic as in ShaderNodeObject: number,boolean,node->swizzable, otherwise do nothing
 export type NodeObject<T> = T extends Node ? Swizzable<T> : T extends number | boolean ? Swizzable<ConstNode> : T;
 
-type MakeObjectOption<T> = T extends Node ? NodeRepresentation : T;
+// opposite of NodeObject: node -> node|swizzable|boolean|number, otherwise do nothing
+type Proxied<T> = T extends Node ? NodeRepresentation<T> : T;
 // https://github.com/microsoft/TypeScript/issues/42435#issuecomment-765557874
-type MakeObjectOptions<T extends readonly [...unknown[]]> = [...{ [index in keyof T]: MakeObjectOption<T[index]> }];
+export type ProxiedTuple<T extends readonly [...unknown[]]> = [...{ [index in keyof T]: Proxied<T[index]> }];
+export type ProxiedObject<T> = { [index in keyof T]: Proxied<T[index]> };
 type RemoveTail<T extends readonly [...unknown[]]> = T extends [unknown, ...infer X] ? X : [];
 type RemoveHeadAndTail<T extends readonly [...unknown[]]> = T extends [unknown, ...infer X, unknown] ? X : [];
 
@@ -121,22 +123,22 @@ export function nodeArray<T extends NodeObjectOption[]>(obj: readonly [...T]): N
 
 export function nodeProxy<T>(
     nodeClass: T,
-): (...params: MakeObjectOptions<GetConstructors<T>>) => Swizzable<ConstructedNode<T>>;
+): (...params: ProxiedTuple<GetConstructors<T>>) => Swizzable<ConstructedNode<T>>;
 
 export function nodeProxy<T, S extends GetPossibleScopes<T>>(
     nodeClass: T,
     scope: S,
-): (...params: MakeObjectOptions<RemoveTail<GetConstructorsByScope<T, S>>>) => Swizzable<ConstructedNode<T>>;
+): (...params: ProxiedTuple<RemoveTail<GetConstructorsByScope<T, S>>>) => Swizzable<ConstructedNode<T>>;
 
 export function nodeProxy<T, S extends GetPossibleScopes<T>>(
     nodeClass: T,
     scope: S,
     factor: NodeObjectOption,
-): (...params: MakeObjectOptions<RemoveHeadAndTail<GetConstructorsByScope<T, S>>>) => Swizzable<ConstructedNode<T>>;
+): (...params: ProxiedTuple<RemoveHeadAndTail<GetConstructorsByScope<T, S>>>) => Swizzable<ConstructedNode<T>>;
 
 export function nodeImmutable<T>(
     nodeClass: T,
-    ...params: MakeObjectOptions<GetConstructors<T>>
+    ...params: ProxiedTuple<GetConstructors<T>>
 ): Swizzable<ConstructedNode<T>>;
 
 export class ShaderNode<T = {}, R extends Node = Node> {
diff --git a/types/three/examples/jsm/nodes/shadernode/ShaderNodeBaseElements.d.ts b/types/three/examples/jsm/nodes/shadernode/ShaderNodeBaseElements.d.ts
index 3b74fe54e..3c499844e 100644
--- a/types/three/examples/jsm/nodes/shadernode/ShaderNodeBaseElements.d.ts
+++ b/types/three/examples/jsm/nodes/shadernode/ShaderNodeBaseElements.d.ts
@@ -13,6 +13,9 @@ import {
     Swizzable,
     NodeRepresentation,
     NodeOrType,
+    NodeObjects,
+    ProxiedObject,
+    ProxiedTuple,
 } from './ShaderNode';
 import { Material, Texture } from '../../../../src/Three';
 import { NodeTypeOption, NodeUserData, NodeValueOption } from '../core/constants';
@@ -22,13 +25,14 @@ import {
     BypassNode,
     CameraNode,
     CodeNode,
+    CodeNodeInclude,
     ComputeNode,
     ContextNode,
-    ConvertNode,
     ExpressionNode,
     FrontFacingNode,
     FunctionCallNode,
     FunctionNode,
+    FunctionNodeParameters,
     InstanceIndexNode,
     MaterialNode,
     MaterialReferenceNode,
@@ -83,8 +87,6 @@ export const imat4: ConvertType;
 export const umat4: ConvertType;
 export const bmat4: ConvertType;
 
-export function func(code: string): ShaderNode<FunctionNode>;
-
 export function uniform(nodeOrType: Node | Swizzable | NodeValueOption): Swizzable;
 
 export function attribute(attributeName: string, nodeType: NodeTypeOption): Swizzable;
@@ -95,10 +97,27 @@ export function code(code: string, nodeType?: NodeTypeOption): Swizzable<CodeNod
 export function context(node: NodeRepresentation, context: NodeBuilderContext): Swizzable<ContextNode>;
 export function expression(snipped?: string, nodeType?: NodeTypeOption): Swizzable<ExpressionNode>;
 
-export function call(
-    functionNode?: NodeRepresentation,
-    parameters?: { [name: string]: Node },
-): Swizzable<FunctionCallNode>;
+// definition: const call = nodeProxy(FunctionCallNode);
+export function call<P extends FunctionNodeParameters>(
+    functionNode?: FunctionNode<P>,
+    parameters?: ProxiedObject<P>,
+): Swizzable<FunctionCallNode<P>>;
+
+export type FnParameters<P extends FunctionNodeParameters> = P extends readonly [...unknown[]]
+    ? ProxiedTuple<P>
+    : readonly [ProxiedObject<P>];
+
+// tslint:disable:no-unnecessary-generics
+export function func<P extends FunctionNodeParameters>(
+    code: string,
+    includes?: CodeNodeInclude[],
+): { call: (...params: FnParameters<P>) => Swizzable };
+
+export function fn<P extends FunctionNodeParameters>(
+    code: string,
+    includes?: CodeNodeInclude[],
+): (...params: FnParameters<P>) => Swizzable;
+// tslint:enable:no-unnecessary-generics
 
 export const instanceIndex: Swizzable<InstanceIndexNode>;
 export function label(node: NodeRepresentation, name?: string): Swizzable<VarNode>;
diff --git a/types/three/test/nodes/nodes-FunctionNode.ts b/types/three/test/nodes/nodes-FunctionNode.ts
new file mode 100644
index 000000000..ea8e67a07
--- /dev/null
+++ b/types/three/test/nodes/nodes-FunctionNode.ts
@@ -0,0 +1,57 @@
+/**
+ * Various tests of func, fn and call
+ */
+
+import {
+    code,
+    fn,
+    uv,
+    func,
+    Node,
+    FunctionNode,
+    call,
+    Swizzable,
+    FunctionCallNode,
+} from 'three/examples/jsm/nodes/Nodes';
+
+import { ProxiedObject } from 'three/examples/jsm/nodes/shadernode/ShaderNode';
+
+export const mx_noise = code('whatever');
+const includes = [mx_noise];
+
+const someFunc1 = new FunctionNode<[a: Node]>();
+const someFunc2 = new FunctionNode<{ a: Node }>();
+
+// tslint:disable-next-line:no-unnecessary-generics
+function assertSwizzable<T extends Node>(_s: Swizzable<T>) {}
+
+type a = ProxiedObject<readonly [Node]>;
+
+assertSwizzable<FunctionCallNode<[Node]>>(call(someFunc1, [1]));
+assertSwizzable<FunctionCallNode<[Node]>>(call(someFunc1, [uv()]));
+assertSwizzable<FunctionCallNode<[Node]>>(call(someFunc1, [uv().xy]));
+assertSwizzable<FunctionCallNode<{ a: Node }>>(call(someFunc2, { a: 1 }));
+assertSwizzable<FunctionCallNode<{ a: Node }>>(call(someFunc2, { a: uv() }));
+assertSwizzable<FunctionCallNode<{ a: Node }>>(call(someFunc2, { a: uv().xy }));
+
+export const mx_cell_noise_float_call = func<[Node]>('float mx_cell_noise_float( vec3 p )', includes);
+export const mx_worley_noise_float_call = func<[Node, Node, Node]>(
+    'float mx_worley_noise_float( vec3 p, float jitter, int metric )',
+    includes,
+);
+export const ab_call = func<{ a: Node; b: Node }>('float mx_cell_noise_float( vec3 p )', includes);
+
+assertSwizzable<Node>(mx_cell_noise_float_call.call(uv()));
+assertSwizzable<Node>(mx_worley_noise_float_call.call(uv(), 1, 1));
+assertSwizzable<Node>(ab_call.call({ a: 1, b: uv() }));
+
+export const mx_cell_noise_float = fn<[Node]>('float mx_cell_noise_float( vec3 p )', includes);
+export const mx_worley_noise_float = fn<[Node, Node, Node]>(
+    'float mx_worley_noise_float( vec3 p, float jitter, int metric )',
+    includes,
+);
+export const ab = fn<{ a: Node; b: Node }>('float mx_cell_noise_float( vec3 p )', includes);
+
+assertSwizzable<Node>(mx_cell_noise_float(uv()));
+assertSwizzable<Node>(mx_worley_noise_float(uv(), 1, 1));
+assertSwizzable<Node>(ab({ a: 1, b: uv() }));
diff --git a/types/three/test/nodes/nodes-ShaderNode.ts b/types/three/test/nodes/nodes-ShaderNode.ts
index 47ea44467..0bb5fb9b5 100644
--- a/types/three/test/nodes/nodes-ShaderNode.ts
+++ b/types/three/test/nodes/nodes-ShaderNode.ts
@@ -22,7 +22,6 @@ import { ConvertType, Swizzable } from 'three/examples/jsm/nodes/shadernode/Shad
 // just to type check
 // tslint:disable-next-line:no-unnecessary-generics
 function assertSwizzable<T extends Node>(_s: Swizzable<T>) {}
-function assertNode(_s: Node) {}
 
 export const color = new ConvertType('color');
 const s = color(1);
diff --git a/types/three/test/nodes/nodes-materialx.ts b/types/three/test/nodes/nodes-materialx.ts
new file mode 100644
index 000000000..a1e6a87af
--- /dev/null
+++ b/types/three/test/nodes/nodes-materialx.ts
@@ -0,0 +1,15 @@
+import {
+    mx_perlin_noise_float,
+    mx_cell_noise_float,
+    mx_worley_noise_float,
+    mx_fractal_noise_float,
+} from 'three/examples/jsm/nodes/materialx/functions/lib/mx_noise';
+
+import { mx_hsvtorgb, mx_rgbtohsv } from 'three/examples/jsm/nodes/materialx/functions/lib/mx_hsv';
+
+mx_perlin_noise_float(1);
+mx_cell_noise_float(1);
+mx_worley_noise_float(1);
+mx_fractal_noise_float(1, 1, 1, 1);
+mx_hsvtorgb(1);
+mx_rgbtohsv(1);
diff --git a/types/three/tsconfig.json b/types/three/tsconfig.json
index dac57dc63..4f63754b3 100644
--- a/types/three/tsconfig.json
+++ b/types/three/tsconfig.json
@@ -63,6 +63,8 @@
         "test/misc/misc-gpucomputationrender.ts",
         "test/nodes/nodes-ColorAdjustmentNode.ts",
         "test/nodes/nodes-Iridescence.ts",
+        "test/nodes/nodes-FunctionNode.ts",
+        "test/nodes/nodes-materialx.ts",
         "test/nodes/nodes-ShaderNode.ts",
         "test/nodes/nodes-ShaderNodeBaseElements.ts",
         "test/nodes/nodes-ShaderNodeElements.ts",