Introduction
Liquid effects are one of the hardest things to get right in AI video generation. Water, smoke, fire, fog — these elements follow complex physical dynamics that are extraordinarily expensive to simulate with traditional methods and notoriously difficult for AI models to learn.
Two AI video generators have emerged as the leading contenders for fluid effects: OpenAI’s Sora 2 (released September 30, 2025) and Luma AI’s Dream Machine 3 (updated in early 2026). Both produce impressive fluid dynamics, but they approach the problem differently and excel in different scenarios.
This article puts both models through their paces on the specific task of generating convincing liquid and atmospheric effects.
Technical Foundations
Sora 2’s Approach
Sora 2 is built on a diffusion transformer architecture derived from DALL-E 3. It processes video as spatial-temporal patches, allowing the transformer’s attention mechanism to model dependencies across both space and time.
For fluid effects, this means Sora 2 can theoretically reason about how a splash at frame 10 should propagate by frame 30. The global attention mechanism gives it an advantage in maintaining physical consistency over longer durations.
Dream Machine 3’s Approach
Luma’s Dream Machine uses a proprietary architecture that the company has not fully disclosed, but external analysis suggests a hybrid approach combining diffusion-based generation with specialized motion estimation modules.
What is clear from the output is that Luma has invested heavily in training on nature and environmental footage. The model appears to have been exposed to a disproportionately large amount of water, weather, and atmospheric video data.
Water: Splashes, Waves, and Reflections
Ocean Waves
Both models generate convincing ocean waves, but with distinct characteristics:
Sora 2 produces waves with excellent physical weight. The water feels heavy, and the interaction between waves and light (caustics, foam, spray) is detailed. Where Sora excels is in the way light penetrates the water’s surface, creating subsurface scattering effects that feel volumetric.
Dream Machine 3 produces waves with superior surface texture. The micro-detail of wave surfaces — the small ripples, the fine spray, the way foam patterns form and dissolve — is noticeably more detailed than Sora’s output. Dream Machine 3’s waves look like they were filmed with a high-speed camera.
Winner: Dream Machine 3, by a narrow margin, for the surface detail and texture quality.
Splashes and Impacts
When an object hits water — a diver entering a pool, a stone dropped in a pond — the resulting splash involves complex dynamics: the initial impact crater, the radial wave, the upward splash column, the droplet formation.
Sora 2 handles the overall splash physics more convincingly. The splash shape, timing, and scale are proportional to the implied impact force. The secondary ripple effects propagate correctly.
Dream Machine 3 produces more visually detailed splashes but occasionally gets the physics slightly wrong — splashes that are too symmetric, droplets that hang in the air too long, or ripples that propagate at implausible speeds.
Winner: Sora 2, for more physically plausible splash dynamics.
Reflections on Water
Water reflections require the model to understand both the water surface geometry and the surrounding scene simultaneously.
Sora 2 handles reflections competently, with reflected images that approximate the correct geometry and brightness. However, reflections sometimes appear slightly “painted” rather than optically accurate.
Dream Machine 3 produces more convincing water reflections, particularly on calm water surfaces. The reflected images show appropriate distortion based on wave height, and the color temperature shift between the scene and its reflection is more natural.
Winner: Dream Machine 3, for more optically convincing reflections.
Smoke and Atmospheric Effects
Smoke Plumes
Smoke involves turbulent fluid dynamics that are challenging to simulate realistically. The key characteristics are: turbulent mixing at the plume edges, density variation within the plume, interaction with ambient air currents, and gradual dissipation.
Sora 2 generates smoke with good large-scale behavior — the plume rises, expands, and dissipates realistically. The internal turbulence is convincing at medium scale.
Dream Machine 3 excels at the fine-scale turbulence within smoke plumes. The wispy, chaotic edges of smoke clouds are more detailed, and the way smoke interacts with light (volumetric scattering) is notably superior.
Winner: Dream Machine 3, particularly for atmospheric and volumetric lighting in smoke.
Fog and Mist
Low-lying fog and mist require different visual treatment from smoke — they are denser, more uniform, and interact with the landscape differently.
Both models handle fog well, but Dream Machine 3 has a clear advantage in producing the kind of atmospheric, mood-setting fog that cinematographers prize. The way fog rolls across terrain, thins out in certain areas, and diffuses light sources is consistently more convincing.
Winner: Dream Machine 3, decisively.
Fire and Combustion
Campfire and Candle Flames
Small-scale fire is a good test case because humans have extensive experience observing it, making errors immediately apparent.
Sora 2 produces fire with good color temperature variation (blue base, yellow body, orange/red tips) and convincing flicker dynamics. The light cast by the fire onto surrounding surfaces is physically plausible.
Dream Machine 3 produces fire with slightly more detailed flame structure — individual tongues of flame are more distinguishable, and the way embers break away and float upward is more convincing.
Winner: Slight edge to Dream Machine 3 on visual detail; slight edge to Sora 2 on lighting interaction. Essentially a tie.
Large-Scale Fire
Conflagrations, explosions, and building fires involve more complex dynamics: rapid expansion, thick black smoke mixing with flame, intense light emission, and heat distortion.
Sora 2 handles large-scale fire more convincingly, likely because the physical dynamics (smoke convection, heat shimmer, structural interaction) benefit from the model’s stronger overall physics simulation.
Dream Machine 3 produces visually striking large fires but sometimes generates physically implausible behavior — fire that spreads too uniformly, or smoke that does not react to wind.
Winner: Sora 2, for large-scale fire dynamics.
Pouring, Dripping, and Viscous Liquids
Pouring Water
A simple pour — water from a pitcher into a glass — tests the model’s ability to generate a coherent stream, correct glass-filling behavior, and appropriate splash/ripple effects within the glass.
Sora 2 handles the overall pour dynamics well. The stream narrows as it falls (correct physics), and the glass fills at a plausible rate.
Dream Machine 3 produces a more visually appealing pour, with better detail on the stream itself (transparency, refraction through the falling water), though the glass-filling dynamics are slightly less precise.
Winner: Tie — each model excels at different aspects.
Viscous Liquids (Honey, Paint, Lava)
Viscous liquids move slowly, stretch, and fold in characteristic patterns. Getting the viscosity “feel” right is critical.
Both models struggle somewhat with viscosity, but Dream Machine 3 generally produces more convincing thick-liquid behavior. Honey dripping from a spoon, paint being poured, or lava flowing over terrain all benefit from Dream Machine’s apparent training advantage on these types of footage.
Winner: Dream Machine 3.
Overall Assessment
| Effect Category | Sora 2 | Dream Machine 3 |
|---|---|---|
| Ocean Waves | Very Good | Excellent |
| Splashes/Impacts | Excellent | Very Good |
| Water Reflections | Good | Very Good |
| Smoke | Very Good | Excellent |
| Fog/Mist | Good | Excellent |
| Small Fire | Very Good | Very Good |
| Large Fire | Excellent | Good |
| Pouring Water | Very Good | Very Good |
| Viscous Liquids | Good | Very Good |
Overall for liquid/fluid effects: Dream Machine 3 has a meaningful advantage, particularly for atmospheric, environmental, and surface-detail-focused work.
Sora 2 retains advantages in:
- Physically complex interactions (splashes, large-scale fire)
- Longer coherent sequences
- Overall scene consistency beyond just the fluid elements
Practical Recommendation
If your primary need is atmospheric footage — moody fog, detailed water surfaces, smoke-filled environments — Dream Machine 3 is the better choice today.
If you need fluid effects within a broader scene that involves complex physics, character interaction, or narrative continuity, Sora 2’s overall scene coherence makes it the stronger option even if individual fluid details are slightly less refined.
For professional creators working across both atmospheric and narrative content, the best results often come from using both tools and compositing the outputs. Flowith provides a multi-model workspace that simplifies this kind of cross-tool workflow, allowing you to generate, compare, and combine outputs from different AI video platforms in a single environment.