Fire and Comps!
Design Challenges
create a photorealistic fire simulation, and composite it onto the plate. You will need to model parts of the fireplace as seen in the plate to get correct lighting and emission.
Software Used:
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Cinema 4D
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Houdini
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After Effects
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Nuke
Credits:
Modeling and Simulation:
Teja Hickenbottom
Fire Appearance Research
Color
Fire typically appears in layers of color. Near the base, it often glows blue or bright white where it is hottest. The middle of the flames is usually yellow or orange, and the outer edges shift into deeper oranges and reds. Embers at the bottom glow red or bright orange as they burn more slowly.
Movement
In a fireplace, the flames move upward in shifting, irregular shapes, constantly changing in height and direction. The fire flickers, curls, and occasionally flares as it consumes the wood. Glowing embers may rise slightly with the heat before falling back, while smoke moves steadily upward.
Setting Up Scene
I used Nuke to track the motion of the original footage, creating a stable 3D camera that matches the movement of the real scene. After establishing the track, I placed temporary 3D cubes in the environment to confirm that the tracking data, scale, and perspective lined up correctly with the live-action background. These placeholders act as visual markers and reference points so that, when you export the camera and scene into Cinema 4D, you can accurately position and integrate the final 3D assets in the exact locations intended within the shot.
After exporting the tracked scene from Nuke, I brought it into Cinema 4D using the same camera and reference geometry to keep everything aligned with the original footage. Once the scene was set up, I replaced the placeholder cubes with my finished 3D models. From there, I adjusted the positioning, scale, lighting, and materials so the objects fit naturally into the shot and interacted convincingly with the real environment.
Simulation Exploration
I imported the log model into Houdini and used a test-geometry human as a reference to scale it accurately. By comparing the log to the human proxy, I was able to adjust its size until it matched realistic proportions within the scene.
Once the source was complete, I navigated to the Pyro FX tab and added a bomb fire effect. Inside the bomb fire node, I copied the pyro simulation and pasted the pyro into the simulation section for further control.
Created a noise around the log and used a couple of layers of vex nodes to copy the point to create layers of lines and merging them with a point vop.
I then edited the settings in the pyro solver and pyro to get the look that I wanted the fire to create.
Importing Sim to Scene
To bring the fire into the scene, I exported the simulation as a VDB and imported it using a Volume Builder. I adjusted the frame range to set the desired start point and changed the placement and the size of the fire to match the fire place. To create the fire texture I applied a Pyro Volume shader. I edited the Pyro Volume settings to get a more accurate look to the fire.
Break Down
Final
