Biologically inspired simulation of livor mortis

Abstract

We present a biologically motivated livor mortis simulation that is capable of modelling the colouration changes in skin caused by blood pooling after death. Our approach consists of a simulation of post mortem blood dynamics and a layered skin shader that is controlled by the haemoglobin and oxygen levels in blood. The object is represented by a layered data structure made of a triangle mesh for the skin and a tetrahedral mesh on which the blood dynamics are simulated. This allows us to simulate the skin discolouration caused by livor mortis, including early patchy appearance, fixation of hypostasis and pressure induced blanching. We demonstrate our approach on two different models and scenarios and compare the results to real world livor mortis photographic examples.

Computer graphics simulation of natural mummification by desiccation

“…Examples of organic decomposition in computer graphics include leaf withering, 13 fruit rotting, 13,14 and livor mortis. 15 Leaf withering is achieved by simulating the osmotic water flow in the leaf's veins. 13 A layered model consisting of a triangle mesh and a Voronoi diagram represents the leaf, where the edges represent the leaf's veins and act as springs.…”

“…The two layers are connected by tracking constraints, as in the livor mortis process. 15 The results will be rendered on a surface mesh, therefore, a mesh-based approach is used for the object representation during simulation. Moisture content information is assigned to the tetrahedral vertices.…”

“…The time from t 0 can be partitioned into time intervals, such that time step is Δt = t n+1 − t n . Applying this to Equation (15) and rearranging it with respect to n+1 yields the following linear equation:…”

“…This is used to compute the light absorption by melanin when computing the hemoglobin contribution to the skin coloration inspired by Donner et al 34 Coloration changes within the dermis were simulated using a look up texture based on hemoglobin h(x, y) and oxygen o(x, y) content information for each pixel (x, y). 15 In order to use this method to render skin coloration changes caused by mummification, the dermis color look-up texture, absorption by melanin and convolution weights need to be adjusted in order to account for the affects of moisture loss in the skin. We modified the look-up texture approach from Frerichs et al, 15 to include coloration changes caused by humidity diffusion and hemoglobin degradation.…”

“…15 In order to use this method to render skin coloration changes caused by mummification, the dermis color look-up texture, absorption by melanin and convolution weights need to be adjusted in order to account for the affects of moisture loss in the skin. We modified the look-up texture approach from Frerichs et al, 15 to include coloration changes caused by humidity diffusion and hemoglobin degradation.…”