在閱讀有關圓錐跟踪的論文時，作者是否犯了錯誤？

Cone tracing is an extension of the sphere tracing algorithm. In addition to the ray, a cone is created and expanded in the marching direction. At each sampling step, the current cone radius is compared with the minimum distance from the distance field. If the SDF value is smaller than the current radius, the cone has intersected an object [14]. This incurs very little additional cost to the normal sphere trace, while providing useful intersection information.

It’s kind of inaccurately stated—by comparing the SDF with a linearly increasing radius, the shape that’s being traced out is a cone with a hemisphere on the end, something like this:

At any point along the horizontal center line, if the distance to the nearest surface is less than the current test radius, the cone-plus-hemisphere has intersected that surface.