1
$\begingroup$

I am trying to create a "stamp" in Blender from overlapping objects, but boolean Modifier doesn't work properly if some faces have the same z value. I have tried different sequences of using boolean and join.

I would like to have an easy way to set the depth of the stap to a specific height for easy handling.

I think the best solution would be to create one face from the outline of the top down projection and extending it in the z-axis, so the boolean modifier works correctly without coplanar faces, but I don't know how to do that.

I would also appreciate other possible solutions to this problem. I know my issue is having coplanar faces, but how do I clean them up in my case? Thanks in advance.

correct stamp result rendered correct stamp result rendered (faces : stick -0.01002m; triangle -0.01m; circle -0.0099m)

result with stick and circle bottom-face same height (similar result after join) result with stick and circle bottom-face same z-value (similar result, after join)

edit view with highlighted circle bottom edit view with highlighted circle bottom

$\endgroup$

3 Answers 3

0
$\begingroup$

Solution to getting a clean stamp to then boolean afterwards:

  • Move all stamp objects to a collection (In my case "Stamp"). Then move all but 1 of those objects into a new nesting collection (In my case "Bits").

enter image description here

  • Select the object that's not in the "Bits" collection, and add a Boolean modifier set to Operand Type of Collection, and select the "Bits" collection. The Solver must be set to Exact. Add a Decimate modifier set to Planar. (Decimate modifier not necessary)

enter image description here

Now duplicate the object with shift+D. Right click to cancel move. Press ctrl+A to open the Apply menu, select Visual Geometry to Mesh. Press G and move the new object to the side. Doing this makes the stamp one object whilst keeping all the old stamp objects untouched.

enter image description here

  • With the new object selected, enter Edit Mode and select any of the top faces. Press shift+S and select Cursor to Selected. Exit Edit Mode, open Context Menu with right click > Set Origin > Set Origin to 3D Cursor. This allows the stamp to be scaled in one direction in the Z axis.

enter image description here

  • When using the Boolean modifier set to Difference. Faces on the same plane must not overlap. In this case, the top of the stamp is just above the cube. The previous step helps keeping that top face where it is.

enter image description here

enter image description here

enter image description here

$\endgroup$
1
  • $\begingroup$ Thank you very much. Setting the cursor position, with collection was what I needed. That way I can scale to an absolute position in meters. $\endgroup$ Jan 7, 2022 at 18:46
1
$\begingroup$

Put all of your overlapping objects into a new collection. On the object being stamped, add a boolean modifier with the Operand Type set to "Collection" and select the newly made collection. This will repeat the bool modifier separately with each object in the collection. The final mesh may come out quite messy, but should be easy to fix with a limited dissolve. (Mesh > Clean up > Limited Dissolve)

enter image description here

$\endgroup$
2
  • $\begingroup$ Using a Collection helps with the Management a little bit, but I still have the same issues if the objects overlapp with same height faces. I don't want to apply the boolean modifies yet, because I would like to move the stamp freely. Just having a Stamp as one Object, so I can change size and height easily. Thanks! $\endgroup$ Jan 7, 2022 at 13:41
  • $\begingroup$ I would like to apply a cleanup on the stamp itself, but limitted disolve doesn't look good in my case and the issue persists. $\endgroup$ Jan 7, 2022 at 14:30
-1
$\begingroup$

For 3D printing you just have to join them (ctrl+j), if you're preparing models in Ultimaker Cura for print, in properties find Keep Disconnected Faces and turn it on. Go to PREVIEW and ensure that all layers are good and the model is ready to print.

$\endgroup$
1
  • $\begingroup$ I would like to print the object beeing stamped and the preview doesn't look good in Cura either after appling join. I would also like, if it also looks ok inside Blender itself, because I plan to use more stamps, but thank you. $\endgroup$ Jan 7, 2022 at 13:09

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .