MultiSub

This page provides information on the V-Ray Multi-Sub Texture.

Overview

The V-Ray Multi-Sub texture distributes multiple textures to many objects via one single material based on specified IDs or random distribution.

In the image shown here, Multi-Sub's Get ID from parameter has its type set to Object ID. Each part of the ball is assigned a texture. The Multi-Sub is then assigned to the diffuse channel of a single VRay Material.

Any texture can be replaced via the Replace With New Texture () button, which activates when you select the texture to be replaced. If the texture is an instance, all copies are changed as well.

UI Paths

||V-Ray Asset Editor|| > Textures (right-click) > Multi-Sub

||V-Ray Asset Editor|| > Create Asset (left-click) > Textures > Multi-Sub

Parameters

Default Color – Allows the user to assign a color or texture. When a texture is selected, it overrides the color as long as the texture checkbox is enabled.

Get ID from – Specifies the meaning of the ID parameters.

Use Face Material ID – When more than one material is applied to the different faces of the same object, SketchUp internally creates face IDs. If all those materials share the same Multi-Sub texture, V-Ray considers the face IDs when feeding the data (color or texture) to the materials.
Note that faces inheriting such a material applied to the group instead will use ID 0. Faces with IDs that do not have a corresponding sub-color/texture use the Default Color.
Use Object ID – The Multi-Sub texture considers the Object IDs of the object when feeding the data (color or texture) to the material.

When adding subtextures to the Multi-Sub texture, the first one always starts with an index of 0. Note that only Face material ID utilizes index 0. When using any other option, please ignore or remove the 0 index texture!

Face IDs are under-the-hood object parameters that mark the designation of different materials applied to a single object. If a texture is present in multiple materials applied to the same object, this mode will randomize them for each material.
A common use case is Proxy Mesh assets with multiple available materials slots but only one material applied to all of them.

Loop Textures – When this option is enabled and the number of shaded IDs exceeds the number of IDs in this texture, the geometry IDs are wrapped to fit the available range.

Random:

By Node Handle – Each node is assigned a unique number (or, "handle") when it is created. This option generates the color index based on that node ID. It is useful because the node handle survives through scene editing. For example, if an object is added, removed, or renamed, the colors remain the same.
By Node Name – Generates a color index based on the name of the node that the texture is applied to.
By Face Material ID – Face Material IDs are differentiated when multiple materials are assigned to the faces of a single mesh.
By Mesh Element – A mesh element is considered each island of connected mesh faces.
By Render ID – The Render ID is an object identifier assigned during Render time.
By Instance ID – Instances are considered objects copied by V-Ray Scatter or instances from a referenced alembic abc file loaded as a Mesh Proxy.
By Object ID – Object IDs can be manually defined for each scene object.

Hue/Saturation/Gamma Variation – Active when the Get ID from parameter is set to some of the Random options. These three parameters randomize the output color during post-processing. Each parameter's value specifies the maximum random deviation from the original value within a given scale. See the Random Hue/Sat/Gamma example below.

Hue Variation – Randomizes hue. The output color hue is modified within [-180°, 180°]. See the Hue Variation example below.
Saturation Variation – Randomizes saturation. The output color saturation varies within [-0.5, 0.5] offset. Values outside [0, 1] are clamped. See the Saturation Variation example below.
Gamma Variation – Randomizes gamma. The output color gamma is gamma-corrected with random gamma (or 1/gamma) within [0..1].

Seed – Changes the randomization pattern.

Example: Hue Variation

The following example shows how Hue Variation changes the scene.

Hue Variation set to 0.

Hue Variation set to 0.25. The Hue is randomly modified within [-45° and +45°] from the initial Red color of the spheres.

Hue Variation set to 0.25. The Hue is randomly modified within [-90° and +90°] from the initial Red color of the spheres.

Hue Variation set to 0.25. The Hue is randomly modified within [-180° and +180°] from the initial Red color of the spheres.

Example: Saturation Variation

The following example shows how Saturation Variation changes the scene.

Saturation Variation set to 0.

Saturation Variation set to 0.5. The Saturation is randomly modified within [-0.25 and +0.25] from the initial color of the spheres.

Saturation Variation set to 1. The Saturation is randomly modified within [-0.5 and +0.5] from the initial color of the spheres.

Example: Random Hue/Sat/Gamma by Use Object ID

The following example shows how the Random Hue/Saturation/Gamma changes the scene. Each of the objects has a separate Object ID set and the Get ID from is set to Use Object ID.