I have been modeling (playing) for a few months and one problem I have been having is when I combine objects’ points using ‘join’, when the object is rendered, there is usually a weird shading that occurs in that area. And on models that have many ‘joints’ the shadows are all over. How do I fix this? Is it a bug or am I doing something wrong?
Two things to try.
1- in edit mode: select all vertecies, hot w and then select remove doubles.
2- also in edit mode: select all again and hit CTRL-N to recalculate the normals.
these are the first two things to try when troubleshooting those “artifacts”