Particles and Procedural Effects – Blog

Dry Ice

June, 2025

Breakdown:

May 28, 2025

Final Render:

Houdini Version: 20.5.278

Renderer: Karma CPU

Avg. Render Time: 30 min/frame (10 min smoke, 20 min background)

Resolution: 1920 X 1080

Number of Lights: 3

To reduce my render times while also increasing detail, I create render layers with the smoke and the background.

Since the weekend, I adjusted the camera angle and reduced the density of the smoke on the ends:

Original
New

May 24, 2025

Fixed Camera Angle:

Feedback from Professor Fowler:

  • Tilt camera to match reference better
  • Start at a later frame
  • Use a ramp to  reduce density at bottom

Render Test #3:

I increased the resolution of the smoke for this render as well as the density in the Karma pyro shader. I still have to work more on the background. For the final, I plan to render out more frames. 

Karma Pyro Shader:

May 20, 2025

Feedback from Professor Fowler:

  • Increase detail in the smoke
  • Increase density in smoke (in shader)
  • Composite wispy smoke over regular smoke

Render Test #2:

  • I found that using microsolvers was giving me more control on the shape of the smoke,
  • I still need to increase the resolution of the smoke, density, and make it a little more string-like
Pyro Post Process Node To Reduce Size

Render Test #1: 

  • Comparing this to my reference, the smoke needs to be much denser
  • I also need to make my smoke much more wispy
  • I also need to increase the resolution of the smoke
Background/Look Dev Reference

Wispy Smoke Test #2:

  • There is still lots of banding here that needs to be fixed
  • I also need to fix the interaction with the colliders, since it goes through the cup
Advect points to smoke for wispy, thin smoke
Inside SOP Solver

Wispy Smoke Test #1:

  • When caching, the file would crash about 30 frames in, so I reduced the number of points and increased the pscale
  • Didn’t give me the result I wanted
  • Cleaned up by using pyro post process node to reduce cache size
    • Helped me increase my point count
    • This version is above

May 19, 2025

By Wednesday, May 21st, I plan to get these things done:

  • Figure out the wispy smoke caching issue
  • Refine the current smoke effect
  • Do a test render

May 18, 2025

I created regular smoke as well as thinner, more wispy smoke. I plan to combine the two to achieve the effect in my reference. 

Buoyancy = -.1

To get more wispy smoke, I advected points using a velocity field. I followed this method: https://pepefx.blogspot.com/2022/01/cigarette-smoke-part-3.html

I switched from using the pyro sop solver to the DOP Network. I also added in a ground plane collider.

I increased the amplitude on the animated noise on my emitter .

While I will continue using my original reference for the smoke, I plan to use the video above is for look-dev and lighting reference.

May 12, 2025

Over the weekend, I started my set up with the billowy smoke shelf tool and replaced the source geometry with one that is closer to the shape of the glass. 

Adding a Collider

At first, the smoke was going through the glass when I added it in as a collider, but Professor Fowler shared a breakdown PDF of a previous student with a similar project. They faced a similar issue as I did because the glass geometry was too thin. I used a peak node to increase the thickness of the collider and started to get better results!

I used wind to make the smoke go downwards and wrap around the top of the cup, but I still need to continue working a lot more on the shape. I also would like to try out the method for creating cigarette smoke that Professor Fowler suggested I look at here: https://pepefx.blogspot.com/2022/01/cigarette-smoke-part-3.html 

May 8, 2025

Project Proposal – Dry Ice

https://www.pexels.com/video/hand-with-syringe-putting-blood-in-smoking-cocktail-5546979/