AI 生影片實戰：Sora、Runway、Pika 怎麼用、怎麼選

One Sentence, One Video Born

Two years ago, it was still considered science fiction, but now you can type a sentence like "a dog running on the beach at sunset," and AI can generate a decent video in just a few seconds. AI video generation is one of the fastest-progressing fields in the past year or two, but with numerous tools available, each with its strengths, choosing the right one is crucial to avoid wasting time.

Mainstream Tools, Each with Its Strengths

• Sora: Developed by OpenAI, it excels at creating coherent scenes with good physical representation, making it suitable for more complete scenarios.
• Runway: A veteran in the field, it offers a complete set of tools (generation, editing, special effects) and is a favorite among creators.
• Pika: Easy to use and with an active community, it's ideal for quick experimentation and fun creations.
• Luma: It can turn images into videos with natural camera movements.
• Veo: Developed by Google, it boasts high image quality and consistency.

How to Write Good Prompts for Video Generation

Similar to generating images, the more specific the description, the better: subject + action + scene + shot + lighting + style. For example, "a Shiba Inu running under a cherry blossom tree, shot from a low angle, backlit, with a cinematic feel." Generating multiple versions and selecting the best one is a common practice. For templates, check out the AI prompt library for image generation.

Current Limitations, Be Prepared

• Short duration: Most tools can only generate a few seconds of video at a time, requiring stitching for longer videos.
• Details can go wrong: Fingers, text, and complex physics often fail.
• Consistency is difficult: Maintaining consistency across shots for the same character is still challenging.
• Cost: High-quality, long videos consume a lot of credits.

How to Use Them Cost-Effectively

First, use the free or low-credit version to test your needs, refine your prompts, and then generate in bulk. Treat AI-generated videos as "raw materials" and combine them with real footage and editing, which is often more practical than seeking "one-click automation."

TheAI Academy Summary and Review

Honestly, AI video generation is currently in a "remarkable but not stable" phase – demos are impressive, but to produce usable products, you still need to generate multiple versions, select the best ones, and edit them. However, the progress is rapid, and learning to use these tools now will give you a head start when they become more mature.

To create complete videos, not just fragments, check out the complete guide to AI video creation.

One-sentence review: AI video generation is currently "remarkable but not stable"; use it as a material library and don't expect one-click solutions to get the most value.

Sources

Official websites of each tool (Sora, Runway, Pika, etc.).