In reality (and I use the 'r' word with caution), the local relationship between space and time is changed. The speed of light is a space-to-time ratio (meters/second) and remains constant in a vacuum. When space is 'stretched', there is more space (or less time) in the local space-time continuum. In this case, the light path must change (i.e. - it must bend) to keep the speed-of-light constant. Our lightray intersection algorithm must take this bending into account.

[Wishful Conjecture: if we could locally rescale the time axis (as a function of the local energy), it may be possible to once again shoot a straight light ray through our new 4D space-time, and perform simple straight line intersections. Maybe a sub-time for each space axis?]

All objects move at the speed of light in 4D spacetime, i.e. the length of the 4D velocity vector is c. As the 4D velocity vector is rotated from the time axis to any spatial axis, the spatial axis component increases while the chronological axis component decreases (per the Pythagorean theorem). Likewise, as the velocity component rotates from the time axis to the space axis, the length counter-rotates from the space axis to the time axis.

3.1.3 Charge Migration

It is the author's conjecture that the local charge density on a Terrell rotated sphere will appear to change as more charged surface comes into view. This charge migration from the poles to the equator may also occur with relativistically rotating bodies thus increasing the apparent charge density orthogonal to the axis of rotation near the sphere's equator.

Since the SR raytracing algorithm is simulating the propagation of photons, insights into this phenomena should be forthcoming.

3.4 Unruh Radiation

This may also be a result of relativistic residue. As a particle accelerates, its length in the direction of acceleration decreases due to Lorentz contraction, e.g. - a sphere becomes oblate. As the length decreases, the particle's charge, which is Lorentz invariant (the charge does not change with the relative speed of the particle) remains constant, hence the charge density increases (charge per unit volume increases). A charged test particle, lying in the plane perpendicular to the axis of acceleration of the accelerated particle, would be affected by this increase in charge density, as described by the Larmor formula (conjecture!). Hence the radiation seems to propagate in a two dimensional plane perpendicular to the direction of acceleration. Conjecture: this is the source of 'breaking' radiation.