**On the Optical Accuracy of the Salvator Mundi**
	Marco(Zhanhang) Liang, Michael T. Goodrich, Shuang Zhao
	University of California, Irvine

![](./sal_org.jpg width=512) ![](./gen_salvator_mundi.jpg width=512)



(#) Abstract

A debate in the scientific literature has arisen regarding whether the orb depicted in
Salvator Mundi, which has been attributed by some experts to Leonardo da Vinci, was
rendered in a optically faithful manner or not. Some hypothesize that it was solid crystal
while others hypothesize that it was hollow, with competing explanations for its apparent
lack of background distortion and its three white spots. 

In this paper, we study the optical
accuracy of the Salvator Mundi using physically based rendering, a sophisticated computer
graphics tool that produces optically accurate images by simulating light transport in virtual
scenes. We created a virtual model of the composition centered on the translucent orb in
the subject’s hand. By synthesizing images under configurations that vary illuminations and
orb material properties, we tested whether it is optically possible to produce an image that
renders the orb similarly to how it appears in the painting. 

Our experiments show that an
optically accurate rendering qualitatively matching that of the painting is indeed possible
using materials, light sources, and scientific knowledge available to Leonardo da Vinci circa
1500. We additionally tested alternative theories regarding the composition of the orb, such
as that it was a solid calcite ball, which provide empirical evidence that such alternatives
are unlikely to produce images similar to the painting, and that the orb is instead hollow.



(#) Downloads

<!-- - Paper: [arXiv](https://arxiv.org/abs/1912.03416) -->
- Paper: [arXiv](./salvator_mundi-arxiv19.pdf)
- Supplemental material: [Github](https://github.com/baconleung1993/salvator_mundi)


(#) Result

(##) Solid vs hollow

![Solid orb](./gen_solid.png width=512) ![Hollow orb](./gen_hollow.png width=512)

<!-- (##) On progress: white spots as specular reflections

![Unrestrained light source](./gen_spots_unrestrained.png width=512) ![Restrained light source](./gen_spot.png width=512) -->








<script>markdeepOptions={tocStyle:'none'};</script>
<!-- Markdeep: --><style class="fallback">body{visibility:hidden;white-space:pre;font-family:monospace}</style><script src="markdeep.min.js" charset="utf-8"></script><script src="https://casual-effects.com/markdeep/latest/markdeep.min.js?" charset="utf-8"></script><script>window.alreadyProcessedMarkdeep||(document.body.style.visibility="visible")</script>