This page provides information about Multi Matte objects in Chaos Vantage.


Overview

The Multi Matte render element object creates red, green, blue, and alpha selection masks based on an object's imported Object ID or Material ID. With this render element object, only three colors are possible: red, green, and blue. For comparison, Material Mask and Object Mask render elements can include a multitude of colors to represent each material or object in a scene with a different color. With Multi Matte, a single R, G, B, or A channel can be used directly as a matte, eliminating the step of selecting the color in the compositing software. This ease of use makes Multi Matte a popular choice for compositors.

To represent all the objects or materials in a scene with just the available red, green, blue, and alpha channels, several Multi Matte render element objects can be created for a single rendering, each with different Material ID or Object ID settings.

A maximum of 16 Multi Matte render element objects can be created.



UI Path

||Right side panel|| > Objects tab > Create new Multi Matte object




Parameters

Object IDs – In this mode the specified ID is checked against the object ID of the intersected object. See the Multi Matte Modes example below.

Material IDs – In this mode the specified ID is checked against the material ID of the material being shaded. See the Multi Matte Modes example below.

R – Adds objects or materials (depending on whether the Object IDs or Material IDs mode is selected) using the specified ID to the red channel. See the Multi Matte Usage example below.

G – Adds objects or materials (depending on whether the Object IDs or Material IDs mode is selected) using the specified ID to the green channel. See the Multi Matte Usage example below.

B – Adds objects or materials (depending on whether the Object IDs or Material IDs mode is selected) using the specified ID to the blue channel. See the Multi Matte Usage example below.

A – Adds objects or materials (depending on whether the Object IDs or Material IDs mode is selected) using the specified ID to the alpha channel.

ID – Sets the ID for the RGBA channels. Setting this ID to 0 disables the ID check and leaves only the include/exclude list.

Include – Specifies objects to be included in the selected channel (red, green, blue, or alpha).

Exclude – Specifies objects to be excluded from the selected channel (red, green, blue, or alpha).

With children – When enabled and if objects in the Include/Exclude list have children, they are automatically included or excluded without the need to specifically pick them to the list.

Enabling the Multi Mattes checkbox in the Render Element dialog renders all visible Multi Matte render element objects available in the scene. To render a subset of the Multi Matte render element objects, disable the visibility of the objects you want to exclude from rendering. 



Examples


Multi Matte Modes

The Multi Matte Render Element is useful for isolating geometry or material in a scene. While Object mask and Material mask render elements perform similar tasks, Multi Matte is often quicker to use in compositing software because it can be made to include only pure red, green, or blue channels to represent objects or materials in the scene. Compositing software often has a feature for easily selecting the red, green, or blue channels in an image for use as mattes. The following example shows the two Multi Matte modes.

In Object ID mode, we set the R (red) to match the bins, G (green) to match the benches, and B (blue) to match the trees.

In Material ID mode, we set the R (red) to match the wood panels material, G (green) to match the metal frame, and B (blue) to match the concrete.

Thus, masks are created in compositing to modify the isolated geometries or materials.


Object ID mode

Material ID mode

Beauty render






Multi Matte Usage

In this example, we set the R (red) to match the wood panels' material ID, the G (green) to match the metal frame's material ID, and the B (blue) to match the concrete's material ID. Thus, masks are created in compositing to modify the isolated surfaces in the scene. See the render before and after compositing.


Material ID mode

Beauty render

Beauty render with Color Corrections