“Tension Map” by CGVirus is a Geometry Nodes Group which calculates the “Tension” (stretching and compression) as your character or mesh deforms due to Deform modifiers (e.g. Armature), Shape Keys, etc.
This tool creates Tension Maps on a shader level. Vertex Groups are not generated.
QuickStart Guide
From the GitHub Repository, download the latest tension map blend file. Currently it’s in the Blender 4.5_above folder. This file contains the GN Group.
In the file you want to apply the Tension map effect, append the GN Group. Go to File > Append, find the downloaded file and double-click it to go into its data. Go into the NodeTree folder, select the “Tension Map” entry and click Append.
Create a new Geometry Nodes modifier for your deforming object. Switch to the Geometry Nodes workspace and inside the Geometry Nodes view, press Shift + A > Group > Tension Map. Place the node Group between the Input and Output so that it connects in the middle. Then connect all Inputs and Outputs like in the image below. (If you’re new to Geometry Nodes, you can watch the video tutorials below for more visual explanation of the process).
Also add a Bake node like in the image below. Make sure it’s set to Still, and not Animation.
Important: place you character in a fully neutral pose (reset armature, other deform modifiers, shapekeys, etc.) and press the Bake button on the Bake node. This saves the default state of your object and is essential for the proper functioning of the Tension effect.
In the older version of this tool for Blender 3.1~4.0, you had to create a duplicate of your deformable character because Geometry Nodes did not have the Bake feature yet. Using the newer addon in newer Blender versions like 4.1 and up is much simpler and therefore recommended.
In the Modifiers tab, expand the Output Attributes panel and give each attribute a name of your choice.
Now you can access the Tension, Compress and Stretch attributes in the Shader editor. Add a Attribute node to any material and set its value to either your Tension, Compress or Stretch.
The Tension attribute is an mix of Compress and Stretch using the Red and Green RGB channels. In most cases it’s simpler to use the Compression/Stretch attribute directly for your shader effects. Tension can be useful to temporarily visualize the tension during setup. If you plug it into the color of your material, it allows you to see the stretching in green and compression in red.