So what does Handplane actually do? I understand it converts worldspace normals to tangent space for your game engine/target app, but what is the benefit of that rather than baking straight to a tangent space map in the first place from xnormal?
What the fuck is handplane an where did you hear about it?
Try reading the webpage first perhaps?
it planes hands, duh
As far as I could tell, handplane makes your normal maps cleaner and gets rid of some 9f the weird artifacts and errors you get with typical normal maps.
This helped me
Different engines use different tangent base methods. Mikkt space is currently the most popular one, and what you'll get from xnormal, or use use in UE4. Unity, UDK, Cyengine, etc. all have different tangent bases they work best with. 3DSMax used to have one for its viewport and a completely different one for its renderer.
If you use a tangent space normal map, it's never going to look quite right unless its synced to your target engine/renderer.
there's no standard for calculating tangent space (mikkt space is hopefully getting there, thank god) so pretty much every 3d software is different. if you bake a normal map in one and import the asset into another (say, from a 3d modeling program to a game engine), your normals may just be a little off or have big fat problems. here's an example of this problem, which i experienced recently. a door model with normals baked in blender; viewed in blender and then in unity.
i ended up fixing it by getting a unity tangent space plugin for xnormal and baking with that. but that's what handplane fixes too.
That's genuinely enraging , I once made something similar, looked fine in blender but faulty in Unity. In Unreal 4 it was fine again.
Handplane is no longer needed since xnormals supports both ue4 and unity tangent space via plugin
unless you want to bake in something other then xnormal...
Why would you?