Tutorial 4: Gridding Two Intersecting Ellipsoids

Tutorial 4. Part 1. Mushroom shaped region formed by two intersecting ellipsoids. Video

What you will learn:

Step 1. Creating the Topology

Load up the Tutorial_4_Part1.fra file and turn off the Cut-Plane and the Global Axis.

In GridPro, it is required to use an internal surface to mesh a convex corner around a sharp edge above 180 degrees. In this case, the internal surface has been provided and is colored in light blue as can be seen in the above picture. We need to create the topology for the full mushroom which includes the cap and stem. However, let’s first answer the question as to why we need an internal surface by inspecting the quality when we grid the stem and cap without it. Create a large rectangular box around both surfaces and then slice it by inserting topology sheets around the stem and intersection as in the picture below.

Step 2. Grid Density

Assign the mushroom stem the same density numbers as in Tutorial 3, leave all of the other surfaces at their default values. See the picture below.

Step 3. Surface Assignments

Now that the topology is created, let’s assign the corners to the surfaces. Since we want to ignore the curved intersecting surface, it will not receive any surface assignments. As for the mushroom stem and cap, according to previous tutorials, our intuition tells us to assign the topology to their respective surfaces with a double assignment at the intersection. Let’s proceed with this method and see what we get. Remember, only the outer topology should be assigned to the surfaces while the wrap remains unassigned so it can converge to equilibrium inside the area.