Introduction
Creating videos from single images using AI is a breakthrough for creators, but maintaining consistent object appearance—especially avoiding weird hallucinated movements—is still challenging. Our 2026 physics-focused "Consistency Benchmark" tests top AI converters to help find the best tool for creators who want reliability.
The Consistency Benchmark: Cat in Space
We used a single "Cat in Space" image to evaluate three leading image-to-video converters. The test criteria focus on how well each tool preserves object permanence, meaning the cat should look like the same cat throughout the generated video, without unrealistic distortions or style shifts.
Why Object Permanence Matters
- Avoids confusing, inconsistent video output
- Essential for brand content, storytelling, and professional use
- Reduces editing overhead downstream
Contenders Overview
Three AI converters were put head-to-head:
Sora 2 — Best Physics
- Excels at realistic physics simulation
- Minimal object deformation
- Strong spatial consistency
Runway Gen-3 — Best Style
- Artistic style focus
- Rich visual effects
- Slight compromises on exact object consistency
Luma Dream Machine — Fastest
- Fast processing speed
- Moderate quality
- Occasional hallucinated movements
Detailed Comparison
Physics & Movement
- Sora 2: Keeps cat’s shape and posture stable across frames, realistic motion flow that respects gravity and inertia.
- Runway Gen-3: Adds impressive style but sometimes alters the cat’s proportions mid-video.
- Luma Dream Machine: Moves quickly but less carefully; cat sometimes warps or stretches oddly.
Visual Consistency
- Sora 2: Most stable color and texture retention.
- Runway Gen-3: Style overlays sometimes disrupt color fidelity.
- Luma Dream Machine: Colors shift inconsistently.
Speed & Usability
- Luma Dream Machine: Processes fastest, ideal for quick drafts.
- Sora 2: Balanced speed with quality.
- Runway Gen-3: Longer rendering times due to stylistic effects.
Final Verdict
Sora 2 leads for object permanence and physics accuracy, making it the top rated image-to-video AI converter in 2026 for creators prioritizing consistency. Runway Gen-3 suits stylized production, while Luma Dream Machine is valuable for fast outputs.
Practical Recommendations for Creators
- Choose Sora 2 when exact object consistency and natural movement matter most.
- Opt for Runway Gen-3 if artistic style effects are your priority.
- Use Luma Dream Machine for rapid prototyping or less critical projects.
Prioritize your needs and test with your own content to confirm the best fit.