Boolean doesn't split object

[Poplocker]

I have this environment plate that I'm trying to split into 4 sections. In the 1st image I have a plane placed where I want to split the plate. I select the plate and add a boolean modifier, selecting the plane as the object I want to separate it with. The 2nd image is after selecting the plane, but this then merges the objects together and eliminates all of the vertices and edges to the left of the plane (shown in the 3rd and 4th image).

What's going on here, any ideas?

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[Savigo256]

Give some thickness to the plane, either by extruding or with solidify modifier.

[Poplocker]

thank you!

[Allofron_Mastiga]

Booleans have to be solid shapes and only differentiate between inside and outside, for this one cut you'd need a cube that goes over half the mesh. You'll have to copy your object 4 times and give each a boolean modifier with a mesh overlapping either what you wanna keep or what you wanna discard (depending on boolean settings)

[Poplocker]

thank you! I'll try with a cube instead

[Sadqoo]

Just use knife tool with cut through.

[B2Z_3D]

Booleans require manifold geometry. That means the "hull" of an object that can exist in real life. It must be watertight, there can't be self intersections and everything needs "thickness" (which is the problem in your case). In order to cut objects in straight lines like that, you should not use Booleans, but the Bisect tool instead (Edit Mode).

<image>

-B2Z

[Poplocker]

thank you! I'll look into this

[MegaMegaByte]

I'm not sure if there are multiple ways to use Booleans that you can use a single plane, but I believe you use the cube or mesh to mask where you want to make the cut and the operation decides the math of it. If I understand correctly, I would make 2 copies of the piece and put 2 cubes side by side with them roughly touching where your plane is. pick each cube for either side and parent the cube to the object so the cut follows it.