---
title: "VRayMtlMDL"
canonical: "https://documentation.chaos.com/space/VMAYA/111739558/VRayMtlMDL"
format: markdown
---
This page provides information on the MDL Material.


## **Overview**

---

<details>
<summary>UI Path: ||Right-click on the geometry|| > Assign New Material...</summary>

||Right-click on the geometry|| **>** Assign New Material... **> VRay** section **> VRay Mtl MDL**


![image](media://d0f1ac9f-6933-46d2-841f-6b60f053d18e)


||V-Ray Shelf|| **> **Right-click to** Create V-Ray Materials **button **> VRay Mtl MDL**


![maya2025_72010_Shelf_VRayMtls.png](media://86b46a4e-7e96-4930-b4d9-acec0f8cf607)


||Hypershade||** > Window** tab** >** **Create... > VRay **section **> VRay Mtl MDL**


![image](media://af134b6c-b7f9-43e4-8877-fec332a0da0a)
</details>


## **Installed Material Library**

---

The following MDL material files are included when installing V-Ray for Maya. They are located in *Local Disk (C:) > Program Files > Chaos > V-Ray > Maya 20xx for x64 > vray > mdl.*




## **Basic**

---

## **Parameters**

---

## **Advanced**

---


## **System Attributes**

---


## **Importing NVIDIA vMaterials**

---

In order for the MDL Material to correctly import NVIDIA vMaterials, the following two paths should be set in the [environment variable](https://docs-chaos.atlassian.net/wiki/spaces/VNS/pages/115605616) shown below:

**VRAY_MDL_PATH_MAYA20yy_x64=%PROGRAMFILES%\Chaos\V-Ray\Maya 20xx for x64\mdl;%PROGRAMDATA%\NVIDIA Corporation\mdl;%USERPROFILE%\Documents\mdl **

where xx is the version of Maya installed.


**Example:**

VRAY_MDL_PATH_MAYA2024_x64=C:\Program Files\Chaos\V-Ray\Maya 2024 for x64\mdl;%PROGRAMDATA%\NVIDIA Corporation\mdl;%USERPROFILE%\Documents\mdl


## **Importing MDL Files from Substance Designer **

---

In some cases, when using MDL files exported from Substance Designer, V-Ray may fail to load some modules. In order to load these modules, a folder needs to be set up before starting Maya, as explained below:

1.  Make a folder, for example, *X:\MDL*, that will act as the MDL repository. Put the MDL modules that are exported from Substance Designer into this folder.

2.  Put the textures needed by the MDL materials in the same repository in their respective subfolder (for example, *X:\MDL\MDL_Plywood_02*).

3.  Tell V-Ray where the MDL repository is by appending it to the **VRAY_MDL_PATH_MAYA20xx_x64** environment variable.

4.  Find the folder where Substance Designer keeps its MDL modules (usually *C:\Program Files\Adobe\Adobe Substance 3D Designer\
esources\view3d\iray\alg* but may differ from version to version) and append its path to the same environment variable. 

In the end, the environment variable should look something like:

**VRAY_MDL_PATH_MAYA2018_x64=C:\Program Files\Chaos\V-Ray\Maya 2018 for x64\mdl;C:\Program Files\Adobe\Adobe Substance 3D Designer\
esources\view3d\iray\alg;X:\MDL**


## **Known Limitations**

---

- *material_emission.mode* is ignored
- *material.backface* is ignored
- *df::diffuse_transmission_bsdf* is not supported
- *df::backscattering_glossy_reflection_bsdf* is not supported
- *df::measured_bsdf* is not supported
- From the “alternative distribution functions”, only *df::microfacet_ggx_smith_bsdf* is implemented
- *df::measured_edf and df::spot_edf* are not supported
- *df::anisotropic_vdf* is not supported
- 3D textures are not yet supported
- The *multiscatter_tint* parameter in *simple_glossy_bsdf, microfacet_ggx_smith_bsdf, ward_geisler_moroder_bsdf* is ignored.
- The tint (*color reflection_tint, color transmission_tint, bsdf base*) modifier overload for separate tinting of the reflective and transmissive light paths is not supported.

## **References**

---

- [NVIDIA Material Definition Language home page](http://www.nvidia.com/object/material-definition-language.html) - The MDL home page at NVIDIA.