How to set an object in your own footage on fire
Upload the shot and name the object that should burn. Vizard Agent builds a mask around that object across every frame, sources real fire, ember and smoke footage, and composites the flames into the mask so the rest of the shot survives untouched.
What do you type into Vizard Agent?
Describe the physical behaviour, not the software. Vizard Agent works out the technique itself, so the useful detail is how the fire should start, how it should spread and what should be left behind. Just as important is what is forbidden to change: the camera, the faces, the background.
Prompt
What does Vizard Agent actually do?
It burns one object instead of regenerating the shot. Handing the whole shot to a generator redoes the faces, the camera move and the background, and gives back something that is not your footage any more. Instead it finds real fire footage, because photographed fire looks like fire, and composites it into a mask. In the session behind this article it:
- Read the metadata of a 1920x1080, H.264 shot at roughly 30fps and 12.34 seconds long, and built a grid of frames to see how the camera moved.
- Checked the audio streams and the original volume levels, so the fire would sit under the existing sound.
- Searched the stock library for fire footage, then separately for embers, smoke and flame licks, plus burning and crackling sound effects, and downloaded them.
- Cropped the object's area, determined its full coordinates and built a pixel coordinate grid.
- Built the object mask and verified it, then refined it twice, once by hand and once by colour segmentation, because a mask a few pixels wide puts flames on the background.
- Tested processing speed and rendered trial frames, validating them before committing to the full render.
When does this not work well?
Compositing an effect into real footage is a masking problem, and masking has honest limits. An object that matches its background, like white on white, is very hard to isolate, and so are fast motion blur, objects that leave frame and fine detail such as hair, mesh or glass edges. Vizard Agent shows you the mask it built and where it struggled.
Common questions
Does the fire look real? It is real fire, filmed. Vizard Agent composites photographed flame rather than rendering it.
Can it burn a person? No, and it should not. Vizard Agent handles objects, props and materials.
Can it add the sound? Yes. Vizard Agent sources burning and crackling effects and mixes them under your original audio.