Modelling the Placenta
I focused on the last major model I had left – the placenta. I realize I haven’t walked through my modelling process before, so now is a great opportunity, as this model was straight-forward and pretty similar to the rest of my process!
Render of fetus and placenta in Redshift
1 – I start with the large shapes, normally built from primitives, curve brushes, and extracts. In this case, I extracted a wall of the uterus and added vasculature with a tapered curve tube brush.
2 – I dynameshed the topology so I could have a base to begin sculpting on.
Since I was working quickly, I kept RGB on the brushes as I worked, so the vasculature would be colored and I wouldn’t have to go back through later.
3 – Using a variety of brushes – mainly the standard (BST) and inflate (BIN) brushes in this case – I built up the forms I wanted. I normally sketch with the clay buildup tool, though (BCB).
4 – I blocked out the edge flow I wanted with Polygroups.
5 – Then I ZRemeshed, using “keep groups”.
With nice topology, I used Alphas and additional sculpting to add fine detail.
7 – With the nice polygroups, I was also able to use the Auto-Unwrap from UVMaster to form some islands. I flattened the model and rearranged the islands in ZBrush to cover the maximum area, but didn’t worry to much about super precise maps.
8 – Within ZBrush, I made a normal map from my subdivisions, a diffuse map from my Polypaint, then hand-painted a depth/SSS map (pictured here) to use in C4D/Redshift later.
9 – The benefit of this map is that, in Redshift, I was able to use the black and white to define the SSS thickness. This allowed the vasculature to not be as “transparent” as the rest of the placenta.
Redshift renders with different materials
Once I got the model and maps into C4d and Redshift, I played with the UCE covering the placenta to try and harmonize the umbilical cord and the placenta. I was finding the UCE was too overwhelming, but without it, the placenta stood out too much. I tried a second mesh with a clear UCE that gained transparency with a Fresnel node, but still wasn’t too happy.
Instead, I changed the material of the umbilical cord UCE to become less transparent and grey as it approached the placenta. The shift to the purple hue harmonized the placenta and cord quite well, and added some nice tonal variety to the renders.To keep some of the UCE feeling, I added the slight grey/yellow tint to the placenta material itself.
Fetus and placenta rendered in Redshift
Screenshot of placenta and umbilical cord in the C4D viewport.
Screenshot of full fetus model in the C4D viewport.
In the same way I did for the naval anchor point, I made a small square and used XPresso to fix its position to the center of the placenta vasculature. I used this square to constrain the umbilical “rope” using a belt tag.
Diaphragm
You might notice the diaphragm in there as well – I whipped that up in ZBrush, keeping the same topology so I could apply the PoseMorphs, and rigged it up with XPresso, similar to all the other morphing organs. No issues there!
Starting Animation
Other than that, I have moved into animating the scenes. There likely won’t be as much to post about, as 90% of it will just be keyframing, but I’ll keep you in the loop if anything fun comes along!