with Texel Density Checker you can:
Calculate Texel Density for model for different texture size (512px - 4096px) or with custom size and aspect ratio
Rescale UV for getting texel density what you want
Use Interactive Checker Material
Copy TD from Active to Selected objects
Vizualize Texel Density with Vertex Colors
Vizualize UV Islands with Vertex Colors
UPDATE 2.3 (05.03.20) for Blender 2.81 and higher
[New] Visualize UV Islands with Random Vertex Color in Viewport
[New] New Option for “Bake TD to Vertex Colors” - Show Gradient with Intermadiate Values (0%, 25%, 50%, 75%, 100% of TD Range)
You can change Gradient Position in Addon Preferences.
UPDATE 2.2.1 (20.02.20) for Blender 2.81 and higher
[Improvement] Increase performance for “TD to Vertex Colors”
[Improvement] Increase performance for “Select Faces with same TD”
[Improvement] More accuracy calculation for N-gons
UPDATE 2.2 (18.02.20) for Blender 2.81 and higher
[New] Baking Texel Density Value to Vertex Colors
Bake User’s TD range (Min/Max TD Values) to RGB gradient (Blue -> Green -> Red).
Baked Vertex Colors not replace exist VC on objects - for Texel Density will be created own VC “td_vis”. After Baking VC viewport shading will be changed to Vertex Color. Also Checker Material supports now Baked VC (Coloring Texture with VC).
For Deleting Baked VC press “Clear TD Vertex Colors”.
[Improvement] Change Checker Texture Type - Color Grid or UV Grid
I hope this addon will be very useful for somebody!