How to write effective prompts in FLUX Kontext? A guide for designers.

Publication date: 23-06-2025  |  Update date: 18-06-2025  | Author: Piotr Kurpiewski

Good visualizations with FLUX Kontext start with… a good prompt. In this guide you’ll learn what a prompt is, how to write one, what to avoid, and which phrases to use to create photorealistic visualizations without rendering. We’ll show concrete examples and the most common mistakes made by designers. If you want to learn to speak the AI language and achieve professional results in seconds, this article is for you!

FLUX Kontext is a breakthrough AI tool that enables the creation of photorealistic interior visualizations without classical rendering. Based on simple views from SketchUp or other programs, it can build a coherent, realistic image in seconds. However, to achieve the best results, you need one thing: a good prompt.

What is a prompt and why does it matter?

A prompt is nothing more than a text instruction you give to the AI to describe what it should generate. It’s a form of communication with the AI that must be both precise and comprehensible enough for the machine. The better you describe what you expect, the greater the chance of a high-quality result.

Principles of effective prompting according to FLUX Kontext

The creators of FLUX Kontext recommend using prompts that have a clear structure and include key information about the desired outcome. Here are the most important guidelines:

• Maintain the camera angle – use phrases like "keep the same camera angle and framing" or "preserve the original perspective".
• Don't describe what is already visible – you don't need to mention elements that are already in the input image (e.g., walls, floors) unless you want to change them.
• Avoid vagueness – instead of "nice room" write "modern loft interior with soft indirect lighting".
• Use strong verbs – e.g. "transform", "enhance", "create", "generate".

Common mistakes in prompts

Many users make similar mistakes that lead to chaotic or inconsistent results. Here are some of them:

Best practices - how to write like a professional?

If you aim for a photorealistic effect, it’s worth using terms associated with photographic and rendering technologies. In the context of V-Ray or Corona, these include: "global illumination", "photorealistic lighting", and "PBR materials". When it comes to photography, a general DSLR reference works well: "DSLR", or even specific lens parameters: "35mm lens" or aperture settings: "f/2.8 aperture".

Such phrases help direct the model toward the desired effect and generate lighting and textures in a way that aligns with the principles of physics and traditional photography.

Example prompts in FLUX Kontext

Watercolor → photorealistic visualization:

"Transform this watercolor sketch into a realistic interior visualization with natural light. Keep the camera angle. Keep the original materials and textures. Make it an ultra-detailed view with global illumination and photo-based rendering materials."

SketchUp → pencil sketch:

"Convert this SketchUp view into a hand-drawn pencil sketch with natural graphite lines, cross-hatching, and visible paper texture. Maintain the original perspective and keep the spatial layout intact."

As you can see, prompts don’t have to be long to deliver good results. The key is precision and a command of the language that the AI "speaks". Try it yourself and find your own style.

If you want to learn how to work with artificial intelligence, check out our Stable Diffusion and Flux course in architecture and interior design - there you will find even more theory dedicated to prompting and concrete examples of using popular models to generate inspirations, textures, editing and post-production of interior and exterior visualizations in the ForgeUI interface.

Conclusion

A good prompt is the key to success when working with FLUX Kontext, as well as other AI tools. A well-formulated instruction will allow you to create visualizations that look like professional renders, but are produced in seconds, without the need for a powerful computer or knowledge of complex software. Remember: precision, simplicity, and familiarity with AI language will make you a true creator of the future!