Mesh deforms when parenting armature with automatic weights

I have recently started blender with my first project of making a character for a game idea. I’ve created a mesh (it’s somewhat messy and imperfect cause I just began, and also tried to have a low-poly vibe) and an armature (which is also imperfect), but when parenting the mesh to the armature it deforms the mesh in the hip region.

I’ve tried several things, and I know this isn’t a rare problem, but all the solutions I’ve seen online are either too complex and go way beyond what I know, are in an older and outdated version of blender, or they aren’t specific to the problem I’m encountering. I have 2 pics (before and after) and the blender file in a google drive file, if anyone wants to figure out what’s happening.

https://drive.google.com/open?id=1x57lDOG7AQ_eIf73vapHxkkbk0FHCNdR

There are a few problems here.

  1. Your armature’s constraints take it way out of rest pose because your pole targets aren’t right. Adjust the pole angles on your IK constraints (or temporarily mute/delete your constraints and work on them only after having a mesh that will more easily let you see what’s going on.)

  2. Your mesh isn’t accepting autoweights well because it’s non-manifold. Go into edit mode, use “select non manifold” operation, fix what you see. Don’t worry about the mirror line, other than to bring it to the actual X axis to close off the model. Or, weight paint manually.

  3. Your bones aren’t named appropriately for a mirror modifier. Your left thigh is “Thigh.L” but your right thigh is “Thigh.R.001”, for example. Fix the names so that your mirror modifier can mirror your weights appropriately.

I really appreciate the help, but I’m having trouble wrapping my head around the fingers and ankle being non-manifold. I’ve never heard the term manifold until your reply, and again all the solutions I look for don’t seem to work. I know the problem arises when I create something using multiple shapes (like the body and the arm being separate) and then try to connect them, but the only fixes I could find was removing doubles and adding faces, which didn’t help with the fingers/feet.

It looks like one reason you didin’t mention is non-contiguous normals, which you can most easily fix by recalculating normals (ctrl n for me, in edit with all selecte.)

That cleared everything up involving it being non-manifold, thanks! I renamed the bones, the mesh is manifold (apart from the mirror line, which I straightened), but didn’t touch the IK constraints as I’m not sure what exactly to do. It currently sinks in the thighs and waste a bit, but at least it’s not distorting them extremely.

At this point I’m not sure where to go; I don’t know if the problem is in the constraints or if I did something else wrong.

Here’s the file

~Edit~

I’m thinking it could be all my jumbled up vertices near the waist region, but again I just don’t know.

Haven’t looked at your updated file.

You’re not going to break anything. Your computer’s not going to blow up because you mess with something in Blender. If you want, save a backup. You learn how to do things by messing with things you don’t understand. That’s how it works.

Look on the constraint tab. I said, “your pole targets aren’t right.” Do you see anything there having to do with poles? Change them and see what happens.

Lol yeah you’re right I’m being a bit too hand-held.