My object is deforming when I union it with a negative part

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#1

I want to make something like a Death Star.

I’m using a negative part shaped like a donut with a really big hole, and it’s supposed to cut out a small part of the center of the sphere.

Union though, isn’t exactly cooperating how I thought it would.
The problem is that instead of perfectly cutting, it deforms the sphere.

I searched Roblox Wiki and developer.roblox.com, but they don’t really cover this problem.
I don’t really know how to solve this part or if I’m supposed to use Blender for this, because I’m an amateur builder.

Unioning, undoing, redoing, etc.:

deathstarfail

How can I solve this problem?

5 Likes
#2

Your not doing anything wrong its just the roblox CSG is the worst, it has so many bugs. This happens to me as well.

1 Like
#3

I’m not 100% sure, I probably shouldn’t bother sending this, but I heard about render fidelity and this might be it…? If someone can confirm this that would be appreciated :thumbsup:

that sphere do be wack doe

This is probably wrong, let me search some more…

Union Bug (Building Deformation) it’s not this, because all you have is a ring shape negating in to a sphere /shrug

My advice is use a mesh, it might be better. Ask a mesh artist if you can’t, they shouldn’t even charge you for something that simple

1 Like
#4

Idk what it is but they broke it. Roblox needs a new union system as this one is outdated and old.

2 Likes
#5

I’m not an expert but you should try using blender to see how it goes.

1 Like
#6

It almost looks like the donut you are removing is the same outer diameter as the sphere. I’d suggest making it noticeably larger around the outside diameter so you can be sure you aren’t trying to leave really thin layers of the sphere on the outer diameter which may mess with the Union.

1 Like
#7

I may be wrong, but I think the reason it deforms like that is because there is a limit to how many tris a union can have. If it reaches it’s limit it will try to reduce the tri count which may distort the shape of the union.

2 Likes
#8

I’ll try that, I was thinking of that but I had to go offline.

#9

Well, every part I’m using right now is a sphere, and a donut shaped object. I don’t exactly think I have any triangles.

1 Like
#10

Wow, I tried it with a 4 by 4 stud sphere, it worked perfectly.

I guess union doesn’t work with big things as well, since that sphere gif I showed was 512 by 512 studs.

image

Now, all I have to do is scale it and now it looks great as 512 by 512 studs:

image

(This image is compared to Baseplate.)

And whoops, since I made the middle part way wider than the Death Star’s, it looks more like StarKiller now.

3 Likes
#11

Haha, glad you got it sorted out! I’m not sure I helped though? Isn’t your post the better solution? Did you mark mine as the solution because of other problems people might have? If this is the case, you can reply to the original post and quote your post and mine, so you can mark 2 posts as the solution :smile:

1 Like
#12

Okay, I did that. :slight_smile:

1 Like