--- title: "Matte Render Elements" canonical: "https://documentation.chaos.com/space/APPSDK/132613060/Matte%20Render%20Elements" format: markdown --- In this chapter, we cover all Matte render elements. Most of them are implemented using the *RenderChannelColor* plugin, unless stated otherwise. ## **Overview** --- A matte render element is an aid for selection masks for the compositing process. The term matte refers to a technique for layering two or more images where parts of each image are masked or blocked from the final composite. When compositing, it can be useful to mask an individual scene object or material in order to include or exclude it in a specific post-production process. A matte render element consists of values and/or solid colors that facilitate easy selection for masking or control purposes. The colors and values generated for each matte render element depend on the type of render element used: While each matte render element has its uses, the MultiMatte Render Element is the most common choice because of its versatility and the usefulness of the render elements it creates. The Render ID Render Element is the least common; it is used only for specialized purposes. ### Examples > ℹ️ Matte elements can be combined with or subtracted from a composite to generate complex mattes. ## **Cryptomatte** --- ### Parameters The Cryptomatte Render Element is accessible through the *RenderChannelCryptomatte *plugin. - **enableDeepOutput** - (Boolean) Specifies whether to include this render element in deep images. - **name** - (String) Displays the name of this render channel. Additional rank layers have an integer suffix appended. The default value is VRayCryptomatte. - **alias **– (Int) Internal unique identifier for this channel type. - **id_type **– (Int) Defines which criteria is used to represent individual cryptomatte object. - 0 = Node name - 1 = Node material name - 2 = Node name with hierarchy (must start with scene/) - 3 = Node user attribute - 4 = Node asset/reference name (must start with asset/) - 5 = Node layer name (must start with layer/) - 6 = Sub object name - 7 = Material path - **user_attribute** – (String) The user attribute name if id_type is 3. - **add_root_object_name**-- (Int) Controls whether the root object name is added to the sub object name in the manifest when id_type is 6. - 0 = No root object name - 1 = Add short name - 2 = Add full name - **num_level **– (Int) The number of Cryptomatte rank layers (the number of distinguishable objects within a pixel). - **id_type_prefix **– (String) Optional prefix to find the proper scene_name slot from the VRayPlugin. - **write_metadata **– (Int) Controls if metadata is appended to the EXR extra attributes. - 0 = The plugin does not append any metadata. - 1 = Writes metadata and manifest. - object_path_start_slash – (Boolean) Prepends forward slash for object paths (if necessary). ### Common Uses After producing a multichannel exr image with the Cryptomatte layer, you can use it in a compositing application, such as Nuke, to color correct the image. This example shows the before and after color correcting. ## **Material ID** --- ### Parameters The Material ID Render Element is accessible through the *RenderChannelMtlID* plugin. - **enableDeepOutput** - (Boolean) Specifies whether to include this render element in deep images. - **name** - (String) The name of the render element containing the denoised image. The default value is MaterialID. ### Common Uses The Material ID Render Element is useful for isolating geometry in a scene so it can be enhanced or adjusted with post-production or compositing software. ![image](media://d24cf535-f79a-4bd6-8adb-83655721befe) Blanket enhanced using Material ID Render Element red channel (as a mask in the composite) ## **Material Select** --- ### Parameters - **base_mtl** – The base material. The alpha result of this material is written to all alpha channels specified in the 'alpha_elements' parameter. - **alpha_elements **– A list of alpha render elements. ### Common Uses The Material Select Render Element is useful for isolating geometry in a scene based on the selected material. In the examples shown, the window frame material was selected. ## **Matte Shadow** --- ### Common Use The Matte Shadows Render Element is useful for changing the appearance of shadowed areas in compositing or image editing software. Below are examples of its use. ![image](media://6f913828-9e77-4afc-8256-d18437b2cb87) Shadows warmed by combining a color-corrected Matte Shadows added to the Raw Lightning Render Element `Matte Shadow + Raw Lighting` > Macro (inline-media-image) ## **Multimatte** --- ### Parameters The MultiMatte Render Element is accessible through the *RenderChannelMultiMatte* plugin. - **enableDeepOutput** – (Boolean) Specifies whether to include this render element in deep images. The default value is 1. - **name** – (String) Displays the name of this render channel. The default value is MultiMatte. - **red_id** – (Int) The object ID that is written as the red channel. Set it to 0 to disable the red channel. - **green_id** – (Int) The object ID that is written as the green channel. Set it to 0 to disable the green channel. - **blue_id** – (Int) The object ID that is written as the blue channel. Set it to 0 to disable the blue channel. - **use_mtl_id** – (Boolean) True to use the material IDs instead of the object IDs - **affect_matte_objects** – (Boolean) False to not affect Matte Objects. A matte object is an object that has been assigned a [Wrapper Material](https://docs-chaos.atlassian.net/wiki/spaces/APPSDK/pages/132744003) with the Matte surface option enabled. - **consider_for_aa** – (Boolean) True to consider this render element for antialiasing (may slow down rendering). - **exclude_list_red** – An exclude list for the red ID. - **exclude_list_red_as_inclusive_set **– (Boolean) True to apply MultiMatte only to objects in *excludeList_red*; false to apply MultiMatte to all objects out of *excludeList_red*. - **exclude_list_green **– An exclude list for the green ID. - **exclude_list_green_as_inclusive_set **– (Boolean) True to apply MultiMatte only to objects in *excludeList_green*; false to apply MultiMatte to all objects out of *excludeList_green*. - **exclude_list_blue **– An exclude list for the blue ID. - **exclude_list_blue_as_inclusive_set **– (Boolean) True to apply MultiMatte only to objects in *excludeList_blue*; false to apply MultiMatte to all objects out of *excludeList_blue*. ### Common Uses The MultiMatte Render Element is useful for isolating geometry in a scene. While other matte render elements perform similar tasks, MultiMatte is often quicker to use in compositing software because it can be made to include only pure red, green, and blue channels to represent objects 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. ![image](media://b089ab8b-cfad-41cf-a14c-438d5daa921d) Curtains color-corrected using matte created from MultiMatte green channel (as a mask in composite) ## **MultiMatte ID** --- ### Parameters The Multi Matte ID Render Element is accessible through the *RenderChannelMtlID* plugin. - **enableDeepOutput** - (Boolean) Specifies whether to include this render element in deep images. - **name** - (String) The name of the render element containing the denoised image. The default value is MaterialID. ## **Object ID** --- ### Parameters The Object ID Render Element is accessible through the *RenderChannelNodeID* plugin. - **enableDeepOutput** - (Boolean) Specifies whether to include this render element in deep images. - **name** - (String)  Displays the name of this render channel. The default value is ObjectID. ### Common Uses The Object ID Render Element is useful for isolating geometry in a scene based on the Object ID. This means that items can be isolated by use of a matte created from the solid colors within the Object ID pass. In the example below the sofa has an Object ID of 1, the dangling light has an Object ID of 4 and the sideboard has an Object ID of 2. ![image](media://75e0854d-d2a5-49b2-9609-98b89c5a9b4e) Ottoman color-corrected using matte created from Object ID Render Element blue channel (as a mask in a composite) ## **Object Select** --- ### Parameters The Object Select Render Element is accessible through the *RenderChannelObjectSelect *plugin. - **enableDeepOutput** - (Boolean) Specifies whether to include this render element in deep images. - **name** - (String)  Displays the name of this render channel. The default value is ObjectSelect. - **id **– (Int) The object/material ID that will be extracted - **ids **– (Int) The object/material IDs (more than one) that will be extracted. - **use_mtl_id **– (Boolean) Specifies whether to use the material IDs instead of the object IDs. - **affect_matte_objects** – (Boolean) Set to False to not affect matte objects. - **consider_for_aa** – (Boolean) Set to True to consider this render element for antialiasing (may slow down rendering). - **invert_selection** – (Boolean) Set to True to use object/material IDs different from the specified by id. - **denoise **– (Boolean) Specifies whether to denoise the channel or not. - **color_mapping** – (Boolean) Specifies whether to apply color mapping to the channel or not. ### Common uses The Object Select Render Element allows items to be isolated for easier control at a composite level. In the example, the curtains are color corrected and tinted yellow. ![image](media://c95fc729-ddf0-4eb8-a63c-ac231baf5a43) Resulting Beauty composite ## **Render ID** --- ### Parameters The Render ID Render Element is accessible through the *RenderChannelRenderID* plugin. - **enableDeepOutput** - (Boolean) Specifies whether to include this render element in deep images. - **name** - (String)  Displays the name of this render channel. The default value is RenderID. ### Common uses The Render ID Render Element is useful for isolating geometry in a scene. This means that items can be isolated by use of a matte created from the solid colors within the Render ID pass. Exact RGB values for any object in the scene can be looked up if the XML report is saved. ## **Wire Color** --- ### Common Uses The Wire Color Render Element is commonly used to create a mask for objects in a scene for color correction or color grading. In the example below, a matte was created for the floor and then used to change the color of the floor by using color correction in composite. ![image](media://27230bee-f58d-439e-8fc9-2d527472b4ef) Color corrections of floor using matte