Can't boolean

heya guys
long time no post but I’m back on blender train :slight_smile:
I’m having trouble using boolean. i’m still on 2.7 btw. working my into 2.8

I am having trouble doing a simple boolean


all I want to do is cut away cylinder from an object but it won’t let me
i have checked object is manifold I am not getting errors it just won’t do as it’s told

any advice would be great

thanks all


Hi !
Firstly, convert your mesh to quads where you can. It’s way more readable, and much better for booleans.
How did you try to achieve your boolean operation ? Through modifiers ? With BoolTool ?
Verify that both of your meshes have their normals well oriented (Could you provide a solid view ?)
Concerning boolean workflow, on flat surface you’ll want to avoid un-needed edges. So it’s ok to go NGon, you’ll clean up the dirty parts after.
If you tried using only modifiers (without the help of addons), you cutter object will keep it’s shading mode. Put it in either wireframe or boundingBox display.

gday Darknoodles

how can I convert to quads? that be great if I can
I’ve always used modifier>booleans is booltool better?
image heres the solid view all my normsls are all good .
what addons are you refering to?

thanks again


BoolTool is an addon included in Blender. It’s not activated by default though.
Once activated, you can for example do a subtract by selecting your cutter then your target object and press CTRL+NUMPAD MINUS. It will automatically turn your cutter in BoundingBox instead of solid.
Booltool will basically makes what you did, but with only 2 keypresses
There is a great chance that your boolean is actually performing the way you did, but you can’t see it as your cutter is displayed as Solid.

To concert your faces to quand, you can do it the quick way by selecting your faces and pressing ALT+J (if i remember well).

thanks heaps mate i’ll try boootool see if it’s easier for me
I’ll change faces n have another go :slight_smile:

I can’t do a simple boolean like this.
trying to cut ball knto face

sorry for mjltible replys

Yes, because your cutter is still in solid shading. Select it and go into the object property (the Orange square logo above the modifier tab). Then go in Viewport Display. There is now a drop-down list, change it from Textured (or solid) to wireframe. Also, Blender has problem with coplanar boolean, so you might need to pull your sphere a bit off you cube.

thank you so much Darknoodles it’s been a while since i used blender and there is always more to learn I am still a novice but hope to get better, thanks again for your patience

1 Like

No problem! You can check my Yotube channel if you want. At the moment, there is pretty much nothing but my addon videos, but i plan on making HardSurface and Boolean tips, and a tutorial on how to model R2D2. I’m waiting for the person who made the blueprint her answer for wether i can use her artwork or not.

If I use booleans to get nice “solid modeling” techniques I literally say goodbye to any topology. This depends on situations, perhaps at times it won’t be a problem such as depending on the material (if is matte, or texture is grunge like having mud or rust) or lighting conditions (if light is low - no high specular reflections).

However the worst case scenario is when the material is shiny and polished like a car surface, or some marble surface. Then at times all mistakes in normals lighting might appear. When something looks wrong manual retopology is needed. Not exactly a matter of getting all quad topology for no reason, since all game engines like Unity or Unreal render only triangles. The problem is the consistency. All-Quads design is only an insurance that triangles are consistent in size and direction rather than being totally random or weird (like having long and thin triangles is a bit of dangerous).

If you want to make sure the normals look right you can use a zebra matcap and preview the look of the surfaces. This is a well known technique in solid modeling programs like Fusion360 or Rhino 3D because they use all of these weird operations to make surfaces (like booleans and spline patches) and chances that something go wrong are very high.

P.S. Correction: Blender has Zebra material. In “solid” view mode > matcaps.