Source code for pbrt, the renderer described in the third edition of "Physically Based Rendering: From Theory To Implementation", by Matt Pharr, Wenzel Jakob, and Greg Humphreys.
At the line 61 of orthographic.cpp，It seems that ray->o should be pCamera + Point3f(pLens.x, pLens.y, 0).
It is more reasonable that the ray starts from a region around with pCamera for an ortho camera.
At the line 61 of orthographic.cpp，It seems that ray->o should be
pCamera + Point3f(pLens.x, pLens.y, 0). It is more reasonable that the ray starts from a region around with pCamera for an ortho camera.