0 the part of a solid shape such as a cone that is between the base of the shape and a parallel plane through the shape or between two parallel planes through the shape -- 平截头体，截头锥体
The ellipsoid volume was derived from length and diameter measurements at several points by approximating the cone ellipsoid as the sum of frustums.
Cone ellipsoid volume was approximated as a sum of frustums from length and diameter measurements at several points along the ellipsoid.
Some authors use "pyramid of vision" as a synonym for view frustum itself, i.e. consider it truncated.
View frustum culling is the process of removing objects that lie completely outside the viewing frustum from the rendering process.
In ray tracing, bounding volumes are used in ray-intersection tests, and in many rendering algorithms, they are used for viewing frustum tests.
Other bases may be used, such as an octagon, or a frustum with star section shape more common to pandoro.
The main crossing towers are 158 m tall with one crossarm atop a frustum framework construction.
The tower is formed as a frustum of a cone.
