An FFF-friendly 3D model needs to have a solid, flat base. There is more than one way the bottom of a model can be flattened. For one, the geometry can be edited to be flat. Alternatively, a floor object can be created and cut out of the object using a Boolean
modifier. Since this project is using the Subdivision Surface modifier, editing the geometry can be complicated, so the floor method will be used.
Looking at the model from the front Ortho view (Numpad 1 and Numpad 5), it's clear that the parts of the tentacles that sit below the X
and Y
axes (the red or green line, depending on the view) is where the model needs to be cut off to make a flat, printable base:
So, let's get started:
The cube cannot be seen in solid view because it's completely inside the octopus, so with the cube still selected, switch to local view (Numpad slash / ) to view the cube alone:
The cube is half above and half below the origin. Fortunately, there's an easy way to make a floor and ensure that, no matter how, it's scaled so that the top remains on the XY
plane.
Z
axis (Z) 1 unit (- + 1):XY
plane. This is because object transformations are made in relation to the object's origin. When the points were all moved in Edit mode, the origin wasn't affected. So now when scaling the top, because it's in line with the cube's origin, it remains on the same plane:In Solid view (Z), it may look as if the octopus has a flat bottom, but in Wireframe view (Z), it is clear that the cube is only hiding the bottom part. For the final model, the bottom needs to be actually flat: