I am new to Blender but have been 3D printing for a while. I am trying to make my own model from an image to print a toy key for a piggy bank. I imported a SVG to get the shape of the key and converted the resulting curve to a mesh for depth. I now have holes from the bitmap tracing of the image that I am trying to fill. My plan for actually completing the project is to fix up the image and generate a new SVG, but I would like to know how to fix holes like this in the future.
You will have to fix the topology of this. This is quite a mess.
A good clean mesh based of quads is easier to fill. To close holes you can select the edges around the hole and press F
I have created this very basic key, by extruding faces from a plane using E with edges selected in top view. You can use the SVG as reference if you want it to match the lines of the model. I then selected all faces in face select mode by double tabbing A and extruded the model up along the Z axis by pressing E.
Then I selected the edges around the model and bevelled them using CTRL+B