SCAD X Harbor Picture week 6

SCAD X HARBOR PICTURE

2/12/20254 min read

February 11, 2025

Feedback / Notes

Mentor Vi:

Avoid extra lighting in Nuke; try not to rely on lighting adjustments in compositing.
The droplet reference looks too viscous. Use your own reference.
The motion of droplet is too linear and continuous—add variation.
The new Shot 4.5 is not different enough from the previous shots.
For the tight close-up of the drop going down toward the petal, add more breathing room.

Mentor Molly:

Check your HDRI.
Consider let the drop falling down more to the bottom of the bottle.
Soften the reflection shapes.

Mentor Emma:

Stripes appear in the cap of Shot 5.
Faceting is visible at the bottom connection.
The tube inside the bottle is missing.

Mentor Hailey:

In Shot 4.5, the fluid looks too jelly-like.
The air pocket in Shot 4.5 should be more consistent.
In Shot 5, all the followers are pointing upward—add variation.
In Shot 4.5, the lighting cards pass over the bottle too quickly.
Reflections on the cap appear flat and too white.

Adjustments

Make the droplet's motion less linear and more organic, and ensure the drop continues to the bottom of the bottle.
add the air pocket in Shot 4.5 to be more consistent.
Ensure fluid in Shot 4.5 doesn’t appear too jelly-like; refine its behavior.

February 12 , 2025

Shot 4 - Water Droplets

I have been struggling with the water droplet effect despite trying three different approaches. None have achieved the desired result yet, but I have found more references that I believe will be useful to follow.

Initially, I attempted an pop sim approach using condensation, but the motion appeared too linear. I thought I could have better control over the round shape and residue, but it didn’t work as expected. Then, I tried a FLIP simulation, but the droplets were unable to stick together properly. Now, I have returned to using Vellum Fluid, which I believe will be the best approach for achieving the desired effect.

Flip X

I also tried another approach using a FLIP simulation, thinking it might give me better control to make the droplet look more like water while still maintaining its shape. I found a useful resource from SideFX comparing FLIP and Vellum Fluid:

SideFX: Vellum vs. FLIP Fluid

After running the FLIP simulation in DOP, even after trying different methods (such as particle advection along a curve), the result was still not what I wanted. I experimented with viscosity and surface tension, and you can see the test results below.

Pop Sim X

For the POP simulation, I scatter points on the surface and use the particle scale to group the points I would like to simulate. I also use VDB analysis to calculate the gradient. In the DOP network, I apply POP Wind to give gravity to the active group and use VOP to make the points stick to the surface by multiplying the surface and the gradient of the volumesamplevfile to the normal, then adding it to the position (P). However, the result isn’t what I expected—the motion is too linear.

Vellum Fluid V

This is the one I want to follow the most.

active group by pscale

VDB analysis to calculate the gradient

VOP to make the points stick to the surface

viscosity 0.01

viscosity 0

Low frequency of noise / low amplitude

high frequency of noise / high amplitude

slap comp

So, I decided to go back to using Vellum Fluid to maintain the droplet's shape while also creating residue after it travels. One of the key pieces of feedback from my mentor was that the motion was too linear. To address this, I used VOP to add noise to the phase.

Here is the SideFX documentation explaining phase settings in Vellum Fluid:
SideFX: Vellum Fluid Phases

I have tried different values for the amplitude and frequency of the noise to achieve an organic shape while still maintaining the residue. I also set the substeps to 16 so the droplet moves in slow motion. However, I cached it out before applying retiming, which helped save a lot of time.