blender: why can't I difference modify this?

Discussion in 'Design and Modeling' started by prismspecs, Mar 19, 2013.

  1. prismspecs
    prismspecs New Member
    Check the file attached. Why can't I do a Boolean modify: difference to cut the little shape out of the big shape?

    Attached Files:

  2. AmLachDesigns
    AmLachDesigns Well-Known Member
    Because the normals on your outer shape are not correct. Select the outer shape, go to Edit, select all vertices and then on the menu to the left, Mesh Tools, click on Normals: Recalculate.

    If you are trying to hollow the object you will have to move the inner object down a bit or at least its lower vertices other wise the Boolean will just create a void in the larger shape.

    For hollowing another approach is to delete all the bottom faces of the shape and then use the Solidify Modifier.

    Good luck
  3. prismspecs
    prismspecs New Member
    Hmm neither of those methods worked for me. Here is another simpler model I'm working on. I want to punch a cylinder half way~ into the triangle.


    Attached Files:

  4. AmLachDesigns
    AmLachDesigns Well-Known Member
    Once again your normals are wrong on the prism.
  5. prismspecs
    prismspecs New Member
    I figured as much. However, employing the technique of selecting all verts in edit mode and clicking recalculate normals did not fix it.
  6. AmLachDesigns
    AmLachDesigns Well-Known Member
    PLus the geometry of your prism is odd. You seem to have overlapping faces, duplicate vertices and unnecessary diagonals. The prism only needs to be 3 rectangles and 2 triangles.

    Remove doubles (vertices).
    Remove the diagonal edges.
    CHeck the normals.
    Try again, should work
    Last edited: Mar 20, 2013