Add Packed Channel


  • Where to find it:


    • Channels Palette / Right Mouse Click
    • Main Window / Channels
    • Main Window / Extension Pack / Channels


  • Shortcut: (unassigned, use "Edit / Shortcuts" to assign)




Packed Channels are channels that contain different information in the Red, Green, Blue and Alpha Channel.

Extension Pack makes it easy to create such a channel


A sample usage could be your Roughness Channel in RED, a Metalness Channel in GREEN, Ambient Occlusion in BLUE etc.

This allows a reduction in amount of texture files and memory used .


Alpha Channels and EXRs


Mari 4 follows the official Open EXR specification when handling Alpha Channels which states:


"OpenEXR images are "premultiplied" - the color channel values are already matted against black using the alpha channel."


Unfortunatelt this means by default when exporting a packed Channel that utilizies an Alpha Channel, the Alpha Channel values will be multiplied against the R, G and B Channels. 


To turn off this behavior for MARI you need to set an Environment Variable


MARI__DONT_TREAT_EXR_PREMULTIPLIED = 1

Video


Options



Presets



Presets allow you to setup your channel packing system only once and then easily apply them across all your projects.


Channel Name Based 


The contents of the Red, Green, Blue and Alpha Channel Boxes are name based.

If you load a preset that contains a link to a channel 'Diffuse' while in your current project

no such channel name exists, the Channel will default to <empty> and will be filled with black


By default the list comes with one preset


    • Last Used Settings

Will open the dialog with your last used Channel Packing System




Channel Row Management



The row management at the top left of the dialog allows you to add additional packed channel rows,

remove selected ones or clear the list.


  • Add Row

Will add a new packed Channel Row


  • Remove Selected Row

Will remove the currently selected packed Channel Row


Selecting a Channel row


You can select a channel row by clicking in one of its empty spaces


  • Clear all Rows

Will remove all packed Channel Rows


Per Row Settings


An empty, default packed channel row


  • Activate Row

When the checkbox is ticked and the dialog is confirmed the packed channel will be created from its settings after the dialog

is confirmed


  • New Channel Name

The Name the resulting Packed Channel should have


  • Red Channel

Which mari channel currently existing in your project should be packed into the red channel of the final packed Channel.

If <empty> the red channel of the final packed Channel will be black


      • Source Color Channel

The Source Color Channel will determine what Color Channel (R,G,B or A) will be used from the selected Mari Channel (Color, Specular etc.).


In the above example the selected Mari Channel is 'Base Color' and the selected Source Channel is 'R' (red), meaning

that the Red Color Channel of the Mari Channel 'Base Color' will make up the specific color channel of the final packed channel.



  • Green Channel

Which mari channel currently existing in your project should be packed into the green channel of the final packed Channel.

If <empty> the green channel of the final packed Channel will be black


      • Source Color Channel

The Source Color Channel will determine what Color Channel (R,G,B or A) will be used from the selected Mari Channel (Color, Specular etc.).


In the above example the selected Mari Channel is 'Base Color' and the selected Source Channel is 'R' (red), meaning

that the Red Color Channel of the Mari Channel 'Base Color' will make up the specific color channel of the final packed channel.




  • Blue Channel

Which mari channel currently existing in your project should be packed into the blue channel of the final packed Channel.

If <empty> the blue channel of the final packed Channel will be black


      • Source Color Channel

The Source Color Channel will determine what Color Channel (R,G,B or A) will be used from the selected Mari Channel (Color, Specular etc.).


In the above example the selected Mari Channel is 'Base Color' and the selected Source Channel is 'R' (red), meaning

that the Red Color Channel of the Mari Channel 'Base Color' will make up the specific color channel of the final packed channel.



  • Alpha Channel

Which mari channel currently existing in your project should be packed into the alpha channel of the final packed Channel.

If <empty> the alpha channel of the final packed Channel will be black


      • Source Color Channel

The Source Color Channel will determine what Color Channel (R,G,B or A) will be used from the selected Mari Channel (Color, Specular etc.).


In the above example the selected Mari Channel is 'Base Color' and the selected Source Channel is 'R' (red), meaning

that the Red Color Channel of the Mari Channel 'Base Color' will make up the specific color channel of the final packed channel.



  • Resolution

Determines the resolution the final packed Channel will be created at.

This will not affect the resolution of any channel linked into the Packed Channel but will only take effect

on export or flattening of the channel.



Resolution can be inherited from any of your selected Channels in the Red Channel,Green Channel, Blue Channel or Alpha Channel

Dropdowns allowing for custom, per-udim resolutions.



  • Depth

Determines the bit depth the final packed Channel will be created at.

This will not affect the bit depth of any channel linked into the Packed Channel but will only take effect

on export or flattening of the channel.



  • Colorspace

Determines the default Colorspace the final packed Channel will be created at.


  • Scalar

If Scalar is ticked on, viewing the Channel in Mari will display raw values in the viewport and not show

the channel through a Viewport Lookup Table (such as sRGB). This is setting is just a Mari Display Setting

and does not affect the look of the final exported channel in any way