[bjano]

It seems to me that the demonstration is calculated in sRGB space, so with non-linear brightness values and I suspect that most of the unnaturalness of the smear is due to that. To simulate the physics this would need to be done with linear brightness values and only at the end converted to sRGB.

(unless some non-linear effects in human visual perception cancel all that out, but it should at least be mentioned if so)

[pierrec]

Thanks for pointing that out. I've done color space conversion in other graphics applications but clearly haven't learned my lesson. I'll double check and update the interactive figures (and text) if it makes sense. The main "torusphere" shader should be fine because the motion blur is non-realistic and hand tuned, but the first couple of interactive figures are a direct application of theory so what you're saying applies to those. Overall I don't think it invalidates the main ideas in the text though.

[WithinReason]

Yes I noticed that the gamma is all wrong, it actually defeats the purpose of the article since you don't get smooth perceived motion blur with the figures. This could have been so much better.

[Solvency]

It's wild to me the author would overlook such a crucial thing (ignoring linear space). But then again, even Adobe barely supports linear and it's 2024.