This heart model is from the Zygote 3D Science model collection. The base materials were also included in the collection. In fact the model comes pre-animated with 36 morph target states (internal valves and chambers included).
The problems that arise with the morph target technique of animating this model are twofold:
1. the morph targets do not take into account the coronary vessel models which hug the surface of the heart. Animating via morph targets results in these static vessels intersecting with the surface of the heart as it pumps. Not good.
2. In my opinion, the included morph target animation sequence, although correct from a technical point of view, lacks fluidity, and comes off rather stiff and rigid.
Using a combination of several deformers, including the mograph displacement deformer with the color white loaded in and spherical falloff, as well as twist deformers, helped with both of the issues, as I was able to apply the deformers to the entire group including the the coronary arteries & veins. I then tweaked the succession of defomer animation until it felt more fluid and "realistic". What you see in the animation above is the reworked result.
I should also note that the materials, although based on the included texture files provided by zygote were also enhanced to allow for more richness in color as well as sub surface scatterring via Arndt von Koenigsmarck's shader plugin Translucent Pro. vreel-3d.de/plugins/Translucent_Doku/links.html
The flickering is a result of Cinema 4d's in-camera depth of field post effect, which is still somewhat a problem when using with animation. I must admit however, although unintentional, I kind of like the effect here.