Barrel Boolean

Question

Barrel Boolean Clip

Hey all,

I have attached a link to issues I'm facing when it comes to using the boolean modifier. Been watching it in slow motion to see what he does, I believe I am taking the proper steps.

Can someone review the clip above and see if I am missing a step from his video?

I have updated the blend files in this google drive as well.

Things I have attempted when applying boolean modifier :

- Calculated normals on both circle and front cube
- Attempted to remove double vertices
- Applying modifier above mirror modifier.
- Adding a face(s) to the circle.
- Selecting the circle then shift selecting the front cube portion of the gun and applying the boolean modifier.
- Not selecting the circle and only selecting the front cube portion of the gun and applying the modifier and selecting the circle only via eye dropper tool.
- I think I have attempted a few other things as well and tried to find common mistakes via YouTube but no luck

This is the only thing I see when applying the boolean is (which disappears from being applied in the objects modifiers list).  It tries to apply the modifier but just applies these fill circles below that I can see in wire frame view.




If I make the circle object invisible there is no negative space.


If I bring the circle object back into visibility, it's there overlaying those two *invisible holes* drawn by the boolean modifier


  • Martin Bergwerf replied
    Solution

    Hi Jonathan,

    You somehow didn't get the Normals right:

    Boole_1.png

    Make sure to Select everything in Edit Mode before recalculating the Normals!

    When they are corrected the Boolean Modifier works as expected:

    Boole_2.png

    1 love
  • Omar Domenech replied
    Solution

    You can check if your faces are pointing in the right direction by enabling "Face Orientation" on your Overlays:

    face Orientation.png

    If your mesh is blue, faces are good. If a face is red, your normals are backwards.

    1 love
  • Jonathan Delorenzo(BirdOfWar ) replied

    Hey Omar and Mark -I have taken your advice and recalculated normals on each object in edit mode (inside and also tried outside)

    However the below barrel does not get recalculated. Is there a reason why? Unless they normals should be backwards here. lol


  • Omar Domenech replied

    That happens sometime. When you SHIFT + N to recalculate, be sure to select "Inside" in the extra menu that pops out down to the left.

    Inside.png

  • Martin Bergwerf replied

    Hey Jonathan, did you select everything (with 'A') in Edit Mode?

    I know I already mentioned this, but I still sometimes forget this and for me it recalculated fine (your file).

    You can also use ALT+N, to get some extra options:

    Nrm.png

    but again, be aware that this only works on the selection.

    1 love
  • Jonathan Delorenzo(BirdOfWar ) replied


    It seems like I can only get the inside or outside to have recalculated normals.

    Is this how this functionality should work?

    Okay..I see.

    We want it red inside blue outside. We want the blue (normal) to subtract the red  (abnormal?) surfaces

    If it's not normal what is it exactly?

    1 love
  • Jonathan Delorenzo(BirdOfWar ) replied

    Okay got it. Thanks for the help. It was the normals as Omar you both mentioned.  Man I was stuck on that for so long.

    Thank you both so much.

    • 🤟🏼
  • Martin Bergwerf replied

    Well, it has absolutely nothing to do with:

    normal and abnormal...

    A Face Normal is a Vector perpendicular to that Face. Per definition in CG, this Vector is normalized, meaning has a length of 1.

    But then there are still 2 possibilities.

    The 'plus' and 'minus' direction of the Normals in CG is decided by the order in which the Vertices were created:

    NORMAL.png

    Deosil is red (bad) and Widdershins is blue (good).

    It's a bit more complicated, but this is the gist of it.


    1 love
  • Jonathan Delorenzo(BirdOfWar ) replied

    Thanks Martin. I will do some more reading regarding the subject. Thanks so much.