How do I make a parametric surface inside of a circle curve/surface?

I am new at grasshopper, and while following a tutorial I realized that I want to make the parametric surface within the bounds of an oval.

I only see 4 sided surfaces and curves tutorials, but no flat circles. Whenever I make my circle into a boundary surface and plug into as a plane in the TriGrid, the final parametric form disappears. Hopefully someone can show me where I can put this oval shape so that grasshopper knows only to make the new parametric surface within the oval bound.

Sun Shade.gh (27.5 KB)

It is impossible to create a triangular grid with equal edge lengths in a circle or ellipse and cover the entire surface.

However, you can generate a triangular grid and select triangles within a curve, turn the triangles into a mesh and use Kangaroo to pull the vertices to the boundary curve. Some of the edge lengths will change, depending on the strength values.

PS: Your file did not include a curve. Next time you can right click on your input curve to Internalize the input in your Grasshopper definition. I created an ellipse in GH…

The second part of your definition can be simplified with a Extrude Point instead of your solution with the individual lines from the base to the tips…

Sun_Shade_mrtn.gh (49.0 KB)