V-Ray Decal Guide: Creating a Wall Panel and Snow Effect in 3ds Max

V-Ray Decal is a tool in V-Ray for 3ds Max that lets you project a material onto another surface completely independently of the target object's UV set. Three separate guides published in Chaos's official documentation show how to use this feature in two different scenarios: creating a wall panel (artwork) in an interior scene, and adding a multi-layered snow effect to rocks and terrain in an exterior scene. This article summarizes both workflows in English.

What you'll learn in this tutorial

• Creating, resizing and positioning a VRayDecal gizmo

• Adding material and displacement onto a decal

• Using a mask to make the decal appear only in specific areas

• Ordering multiple decals with the Order parameter and excluding certain objects from being affected via the Exclude list

• Adjusting the smoothness of the projection's transition onto the surface with Normal angle and Fade out angle

Requirements

• 3ds Max and V-Ray; V-Ray 6 for 3ds Max is required for support of user-defined attributes (VRayUserScalar/VRayUserColor)

• Access to the Chaos Cosmos library (the objects in the example scenes come from here)

• The sample scene files provided by Chaos (downloadable), or the free trial version if you don't have a license

Step 1: Creating a VRayDecal for the wall panel

1. From the V-Ray menu, go to Create > Geometry and select V-Ray Decal; alternatively, you can use the icon on the V-Ray toolbar or the VRayDecal button in the Command panel.

2. In the Create tab of the Command panel, enable the AutoGrid option and draw the decal gizmo onto the wall surface.

3. In the Modify tab, adjust the Width and Length parameters to match the size of the panel (in the example guide, both are set to 120 units).

4. Keep the Projection depth value large enough to intersect with the wall geometry; otherwise the projection won't occur.

Since the decal has no material yet, it renders in its default wireframe color.

Step 2: Adding material, displacement and mask

1. In the Material Editor, create a new VRayMtl, setting the Reflection color and Glossiness value (0.65 in the guide) to give it a soft interior paint look.

2. For frame detail, create a Gradient Ramp map, set its type to Box, interpolation to Solid, and soften the corners with the Blur value.

3. Connect this map to the material's Displace slot; set the Displace amount (8 in the example).

4. If you enable the "Use only decal displacement" option in the decal parameters, the canvas surface remains flat while only the frame receives displacement.

5. A black-and-white Gradient Ramp or texture-based Mask can be added so the decal appears only in a specific area (for example, within the frame).

Step 3: Layering and ordering multiple decals

Chaos's second guide shows how multiple VRayDecals can be layered on top of each other in the same scene:

• Each decal is given a different Order value to determine which appears on top (a higher Order value is placed above).

• Using the Exclude/Include list, specific objects (such as a chair or candlestick in the example) can be excluded from the decal's effect.

• Using VRayBlendMtl, separate materials can be defined for the panel's frame and canvas and blended together with a mask.

Step 4: Using multi-layered decals for the snow effect

The same technique can also be used to create snow in exterior scenes. The guide defines three separate VRayDecals:

Each decal is configured with an Exclude list so the lake, tree proxies or rocks are not affected. Micro-detail is added to the close-up decals using VRayNoiseTex for displacement and bump; the "Use only decal bump" option prevents the terrain's own bump from doubling up on the snow. Finally, the Normal angle and Fade out angle parameters control how naturally the snow projection transitions at the rock edges; in the example, Normal angle is set to 75 and Fade out angle to 85.

What this means for architecture and archviz workflows

This method saves time for offices that want to break up repetitive wall textures in interior visualization or produce different variations on a single model, without requiring UV unwrapping or separate geometry modeling. For exterior/landscape visualization, it enables quickly testing seasonal effects such as snow, dirt or moss on the same terrain model. One important point to note is that VRayDecal's displacement effect doesn't work on proxy objects; for elements like Chaos Cosmos tree proxies, it's recommended to use pre-built geometric snow variations instead.

Common mistakes

• Not keeping the Projection depth value large enough: the decal won't project at all if it doesn't intersect with the geometry beneath it.

• Using high displacement on low-poly geometry: artifacts can appear when the camera gets close; 16-bit/32-bit maps and subdivided geometry are recommended.

• Forgetting to set Order values when using multiple decals: in this case, which decal appears on top can be unpredictable.

• Expecting results without knowing that decal displacement doesn't work on proxy objects.

Next steps

After learning this technique, you can experiment with different mask types (Composite node, texture-based mask) in your own scene to create more complex layered surfaces, and explore the ready-made decal presets in the Chaos Cosmos library.

Source and license

This tutorial has been adapted into English from the official guides "VRayDecal," "How to Apply V-Ray Displacement on V-Ray Decal - Part I," "How to Apply Multiple Decals - Part II," and "How to Create Snow with VRayDecal," published on Chaos's official documentation site.