Mtlx Viewer for VS Code

See your MaterialX materials without leaving the editor.

Open any .mtlx or .mtlx.zip file and get a live, physically based 3D preview, an interactive node graph, and a full validation report, all in one tab. Free and open source, built on the same mtlx-core library as the CLI and this site's viewer.

Part of the Mtlx suite of web-focused MaterialX tools.

Install from the VS Code Marketplace Install from Open VSX

Mtlx Viewer switching between the 3D preview and the node graph

Real-time 3D previewTotem, sphere, cube, plane or your own glTF model, lit by HDR environments with bloom, AO and tone mapping.
Node graph viewPan, zoom and click through nodes and nested node graphs to inspect every parameter.
Validation at a glanceStructure, types, dependencies, textures and renderer support are checked as the file opens.
Live reloadSave the material or any texture it uses and the preview updates.
One-click packagingRight-click in Explorer to bundle a .mtlx and its textures into a .mtlx.zip, or unpack one.
Your lighting, your modelsAdd HDR/EXR environments and glTF/GLB geometry from disk or a URL.

Use Open VSX for Cursor, VSCodium and other VS Code-compatible editors that can't use the Microsoft Marketplace. Requires desktop VS Code 1.85+ with GPU acceleration.

Viewer settings

Set preview defaults under Settings → Mtlx Viewer, or in user/workspace settings.json. Everything can also be changed per preview from the Viewer settings panel.

Extension viewer settings and defaults
Setting	Default	Values and behavior
`mtlx.preview.ibls`	`[]`	Additional named equirectangular .hdr, .exr, .png, .jpg / .jpeg files.
`mtlx.preview.defaultIbl`	`"bridge"`	bridge, studio, or an additional IBL name.
`mtlx.preview.autoRotate`	`true`	Rotate by default. Reduced motion takes precedence; rotation can still be enabled manually.
`mtlx.preview.bloom`	`true`	Enable HDR bloom by default.
`mtlx.preview.ao`	`true`	Enable full-resolution, denoised GTAO by default.
`mtlx.preview.toneMapping`	`"neutral"`	neutral, aces (ACES Filmic), agx, reinhard, cineon, linear, none.
`mtlx.preview.background`	`"environment"`	environment shows the IBL behind the model; none leaves it transparent.
`mtlx.preview.geometries`	`[]`	Additional named .gltf / .glb mesh scenes.
`mtlx.preview.defaultGeometry`	`"totem"`	totem, sphere, cube, plane, or an additional geometry name.

Each additional asset has a name and a source file path or HTTP(S) URL. Replace these example paths and URLs with your files:

{
  "mtlx.preview.ibls": [
    { "name": "courtyard", "source": "~/IBLs/courtyard.hdr" },
    { "name": "gallery", "source": "https://example.com/ibl/gallery.exr" }
  ],
  "mtlx.preview.defaultIbl": "courtyard",
  "mtlx.preview.autoRotate": false,
  "mtlx.preview.bloom": true,
  "mtlx.preview.ao": true,
  "mtlx.preview.toneMapping": "neutral",
  "mtlx.preview.background": "environment",
  "mtlx.preview.geometries": [
    { "name": "bust", "source": "models/bust.gltf" },
    { "name": "sample_mesh", "source": "https://example.com/models/sample.glb" }
  ],
  "mtlx.preview.defaultGeometry": "bust"
}

Names are case-sensitive identifiers matching [a-zA-Z_][a-zA-Z0-9_]*: start with a letter or underscore, then use letters, digits or underscores. Duplicates within a list and built-in names are rejected. IBL and geometry names are separate namespaces, so a custom name can appear in both.

Relative paths resolve from the material's workspace folder, or its own folder when no workspace folder exists. Absolute paths and ~/ refer to the extension host's filesystem. HTTP(S) URLs are read by the extension host. glTF buffers and images resolve relative to the geometry file, including the final URL after a redirect. Custom geometry uses the selected MaterialX material, replacing its original materials. Draco, Meshopt and KTX2 decoders are not configured.

Assets load when selected, with a 128 MiB limit per IBL or geometry including its sidecars and at most 256 external glTF resources. Refresh reloads assets. Configuration edits refresh visible previews and reapply defaults; manual choices survive ordinary refreshes and tab recreation until settings change. Invalid entries and defaults appear in settings diagnostics and fall back to built-ins. Load failures keep the current preview, or use a built-in fallback if the initial asset fails.