Using MeshLab for fixing normals

In this recipe, we're going to learn how to use MeshLab to visually inspect and correct the face normals of a model. MeshLab has a good collection of tools to repair and modify face normals. Using the selection tools, we'll be able to choose the faces we want to repair.

Getting ready

You'll need MeshLab and the extended capsule file model that you modified with SketchUp in the previous recipe.

How to do it...

We will proceed as follows:

1. Load the model in MeshLab. MeshLab indicates inverted normals by displaying the faces in black. We can see this in the following image:
   
2. Let's take a look at the normals. We can do this in MeshLab by selecting Render in the menu and then Show Normal/Curvature from the list. Not only does MeshLab display the face normals (blue lines), but it also displays the vertex normals (violet lines).
3. Go to the icon tray and select the Flatlines view.
4. The inverted normals are difficult to see, so choose Wireframe for the view...