How to make a perforated plate?

Question

I've been using blender for a few months now, but I'm new to this community. I need to design a circular plate with a pattern of round holes. Here is the plate I need to make, and the pattern.

I made a bunch of Bezier Circles and tried to Knife Project them into the plate, but that obviously didn't work (blender kept freezing and crashing). So, is there any way I can do that?

Answer 1

For best results you can either combine curve circles in 2D mode, then keep it as a curve object and extrude/bevel as needed OR you can create a mesh plate circle and a group of mesh cylinders and use the boolean modifier. You won't get subsurf on the inner holes this way but it's better if the plate has to be a mesh.

Option 1 - Joined Curves in 2D Mode

Create the small holes as bezier curves as well as the large plate circle. Make sure all are in 2D mode, and then select all, including the large cirlce and press CTRL J to combine them all into one Curve object. Because you are in 2D mode the inner circles will cut out the the outer plate circle. Then you can extrude the curve and add a bevel. Keeping it in Curve mode will give you the best smoothness on the inside of the hole cutouts. If you convert back to mesh, you won't have the same level of smoothness, and adding subsurf will introduce shading errors.

Option 2 - Cylinder Group with Boolean Modifier

1. Create a Mesh Circle for the plate. You can extrude/bevel/subsurf it to get it looking right.

2. Then take your group of bezier circles, join them together into one object (we'll call it "Tubes").

3. Reduce the curve resolution (Preview and Render) to the lowest possible while still maintaining a circular shape (2 or 3 usually works, we need lowest geometry possible and will regain our smooth curve with subsurf later on)

4. Make sure the Tubes curve object is in 3D mode (this is to avoid creating caps in the mesh cylinders) and then convert the Tubes object to mesh with ALTC

5. In Edit Mode extrude the circles vertically so that they will be greater than the thickness of your plate mesh.

6. Add a Boolean modifier to the Plate mesh and select the Tubes object as the target object. Select Difference as the mode. Then set viewport and render visiblitiy of the Tubes object to off in the Outline. You'll see perfectly cut holes in your plate object. (Note: you control the smoothness of the holes with subsurf on the Tubes object)

7. In order to hide some viewport surface errors, select the Plate object, go to Object Data toolset, in the Normals panel, check the Autosmooth options, and change the Angle to 30 degrees. You should now have perfectly smooth surface with smooth holes cut through.

Answer 2

My workflow is as follows:

1. Start with a plane and subdivide it a bunch of times to create a mesh. Use the Inset Polygon tool (I) with the Individual Faces option and delete the resulting faces.
2. Next add a 1 level Subdivision Surface modifier and apply it. Optionally, select the edge loops around the circular holes and apply the LoopTools addon Circle command to them. The result is subtle but it ensure the holes appear like perfect circles.

3. To make alternate rows offset from one another, delete all but two rows of the mesh. Use the Separate command (Y) and with Vertex snapping enabled move the bottom row into position. Separate and move the end of the row so that it fits into the space on the left.

4. Duplicate the result several times and Remove Doubles to make a square mesh of circular holes.

5. Create a polygon circle above the mesh. Select the circle first, then the mesh and Tab into edit mode.

6. From a top orthographic view, use the Knife Project tool to cut the geometry. Invert the selection (Ctrl + I) and delete the unwanted area.

7. At this point you can either add a Subdivision Surface modifier to smooth the mesh or cleanup the resulting ngons, if you need all quad topology.

Full quad topology is achievable with a little effort. I just merged vertices and collapsed edges of the ngons. Left disc 1,714 verts, 1,412 faces. Right disc 1,950 verts, 1,576 faces.

Incidentally, I prefer the look of the perforated disc with just whole holes. The part holes around the edges look untidy to my eyes.

Answer 3

A lazy, destructive option, for orthogonal grids:

1. Create Grid
2. Face Menu > Poke all faces
3. Select a 8-way vertex, ShiftG select others by similar number of connecting edges
4. CtrlShiftB Bevel the vertices
5. Face mode, X delete the still selected faces
6. Modifiers: Solidifiy, Bevel(by angle), Subdivide.

If someone can make this entirely procedural, I'd love to hear it.. (I Can't get the Mask modifier to cut out the right bits.)