# Objective:

Convert imported CAD sketches into lattices.

# Applies to:

• Lattices
• Branched Lattice

# Procedure:

• nTopology imports all CAD sketches as a 'Curve' type.
• If your part only has sketches without any models, it may appear blank in the graphic window. To access the curves, open up the properties and drag out the Curves chip.

### 2. Convert the Curves into Line Segments

This step uses a Custom Block designed by Olaf Diegel, a Professor of Additive Manufacturing at the University of Auckland. It is an excellent method of converting sketches into line segments.

The custom block uses the Equidistant Points on a Curve block to add a point at the end of each curve. The Line Segment block converts these points into line segments.

When the Increment input is longer than the curve, it adds the points at the ends of the curve. You can download this Custom Block here (shown below).

• Input the curves chip from Step 1 into the Curve input in the Custom Block.

Update: If you want to convert curved CAD sketches, use Version 2 of the Custom Block. This version builds a Curve using the Line Segments. Download the Custom Block to take a closer look.

### 3. Convert Line Segments into a Branched Lattice

Now we need to convert our line segments into a lattice type. The best method for this is using the Branched Lattice block. However, if we have a list, we can't input it into the Branched Lattice block. Instead, we need to use a Custom Block that uses the Branched Lattice block (shown below). You can download this Custom Block here.

The reason for this is that the inputs of a notebook are contained in variables, and variables cannot list process. However, once it's being used as a Custom Block, it's a block like any other and therefore can list process

Note: This is not equivalent to putting the list into the input but instead running the Custom Block multiple times, once for each element in the list.

• Input the block from Step 2 into this Custom Block.

Remember that the Branched Lattice Custom Block can't be a variable since it can't process lists. If you get this error, Right-click and Remove Variable Contents.

And that’s it! You’ve successfully converted your sketch into a lattice type

From here, there are several options on what you can do with your lattice. One option is turning the lattice into a Custom Implicit Unit Cell. This process may be slow, and we recommend using Thicken Body and Boolean Union for the best results.

Are you still having issues? Contact the support team, and we’ll be happy to help!

# Keywords:

cad lattice convert curve line how-to branch sketch segment branched curves sketching