Deleting parts of your 3D mesh is a process that most 3D modelers at a certain point have to do, whether it’s creating a hole to attach an arm, or deleting part of the mesh that is not useful anymore dealing with a hole in your mesh is something that you must know how to handle.
In this tutorial we will teach you how to fix open holes in your 3D mesh and explain 2 ways to fill those holes:
- Fill Method
- Grid Fill Method
Let’s dive right away and learn!
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What is a Hole in a 3D Mesh?
A hole in a 3D mesh is an empty area where polygons used to exist, It happens if you delete one part of your mesh which will reveal what’s inside of your mesh.
To create a hole, simply create a UV sphere by clicking Shift+A and then select UV Sphere.
After the sphere is created press Tab on the keyboard and switch to Edit Mode.
Press 3 on your keyboard to switch to face selection mode and then select all the faces you want to remove press X and choose Faces from the delete menu.
What we will end up with is a hole where we deleted the polygon and here you can see its orange contour edges in the following image.
Why is a Hole in a 3D Mesh a Bad Thing?
A hole in a 3D mesh is bad for many reasons:
- It’s bad for animation as there are no vertices, edges or faces to be animated
- It doesn’t render anything as there are no faces to render
- No texture is applied as there are no faces or UVs to texture.
That being said there are instances where a hole in a 3D mesh is placed on purpose and those cases are in a gaming workflow where for example bottom side of a pole that is planted in the ground is not shown and not visible.
Check out this tutorial to learn how to Create Grass in Blender!
To optimize the mesh we delete any face that is not shown for a better performance.
Fill Holes in Blender
Alright in the previous example, we created a hole in our 3D sphere but now we want to see ways to fix that hole and fill it up, and that’s exactly what we will do now “Fill” the hole created.
First thing we need to be in “Edit Mode” If you are not press Tab on the keyboard and click edit mode, then press 2 to enter Edge mode.
Double left-click on the open edge of the hole we created and it will highlight it in orange.
Select the Face menu up top and click on “Fill” or use the shortcut Alt+F.
Then that hole is filled with faces as you can see in the image below, but keep in mind it fills the hole in a NON-QUAD way meaning with triangles, that could work for a game workflow as everything gets triangulated anyways when imported to a game engine like Unity.
But if you want to use the 3D mesh for high-quality animation or film purposes then this solution won’t be suitable, but luckily the next method would solve this.
Grid Fill Holes in Blender
What if you want to fill the hole in our 3D mesh with quads, just like it used to be and not triangles, Well there is a way for that and it’s called “Grid Fill”.
Just like we did before in “Edit Mode” press 2 and then double left-click on the surrounding edge as we did before.
Go to the Face menu and right under fill we can see we have another option which is “Grid Fill” Click on that.
As you can see Blender went on and filled the hole with quad faces and connected everything together nicely.
Mostly I use grid fills as it results in a clean mesh, but when using a triangulated mesh or a very low poly one fill could be the better solution.
Filling holes or in other software called Capping etc. is an essential process every 3D modeler needs to know and Blender is very easy all you need to know is there are two commands, Fill or by pressing Alt+F and Grid Fill and they are in the Face menu.
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