# Objective
The `Cone` primitive should support meshing.
## Solution
Implement meshing for the `Cone` primitive. The default cone has a
height of 1 and a base radius of 0.5, and is centered at the origin.
An issue with cone meshes is that the tip does not really have a normal
that works, even with duplicated vertices. This PR uses only a single
vertex for the tip, with a normal of zero; this results in an "invalid"
normal that gets ignored by the fragment shader. This seems to be the
only approach we have for perfectly smooth cones. For discussion on the
topic, see #10298 and #5891.
Another thing to note is that the cone uses polar coordinates for the
UVs:
<img
src="https://github.com/bevyengine/bevy/assets/57632562/e101ded9-110a-4ac4-a98d-f1e4d740a24a"
alt="cone" width="400" />
This way, textures are applied as if looking at the cone from above:
<img
src="https://github.com/bevyengine/bevy/assets/57632562/8dea00f1-a283-4bc4-9676-91e8d4adb07a"
alt="texture" width="200" />
<img
src="https://github.com/bevyengine/bevy/assets/57632562/d9d1b5e6-a8ba-4690-b599-904dd85777a1"
alt="cone" width="200" />
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