SimuSEM Tutorial: Custom Shapes, Part 1
- using primitive shapes and Boolean operations
- modifying planar shapes using Blender's editing tools
This tutorial will discuss using Blender's editing tools to modify planar shapes. Any convex shape that is composed of only flat planes (what we will call a multiplane shape) in Blender will be represented correctly in a simulation. In SimuSEM 3.0, the user is responsible for creating convex multiplane shapes. This requirement is not a significant restriction since any multiplane shape can be split into 2 or more shapes that are convex.
Blender has many tools that can be used to edit shapes, and any can be used as long as final edited shapes are multiplane and convex. This tutorial will describe some methods of editing shapes that we have found useful.
1. Edit vertices, edges and faces directly in Edit Mode.
Start by selecting the shape you wish to edit and switching to Edit Mode. The three boxes just to the right of the mode selection that appear when you are in Edit Mode allow you to select either vertices, edges or faces, respectively in the selected shape. The selected vertex, edge or face can now be modified directly.
When you are done, make sure you switch back to object mode. Many SimuSEM tools are not available in Edit Mode.
2. Use a construction block and difference Boolean modifier
A block is a good shape to start with when creating a custom multiplane shape.Let's say that you want to create an a slanted top surface at a known angle, like this:
- First create the block that you will modify as well as a construction block, which is red in this example.
- Then rotate the red block to the desired angle.
- Make sure the scale of both objects are the same. You can set the scale of all selected objects to 1 by pressing ctrl-a, s. (Hold down shift key to select more than one object).
- Next position the red block so that it overlaps the section of the sample that you want to remove. The red block should be large enough to overlap the entire section to be removed.
- Next, select the block to be cut and click on the blue wrench in the Properties Panel to add a Boolean modifier.
- In the Boolean modifier panel, choose Difference and the Object field should show the construction block.
- Then, make sure the red construction block is covering only the section to be removed, click on the down arrow at the top right of the Boolean panel and choose Apply. Once you click on apply, the cut area can no longer be modified.
- Finally, delete the red block.
If you want the sloped surface to start a certain distance from the bottom of the shape, you can create another construction block that can be used to align the slanted block as shown here:
Warning: Don’t make changes to any other modifiers as that may change how the geometry is described to the simulation.
Methods of accurately aligning shapes will be covered in other tutorials.