Using 3D-Agent
Prompting guidelines
Brief 3D-Agent the way you’d brief a 3D artist. The best prompts plan first, build in pieces and describe the result you want.
Plan first
For big or unclear tasks, get a plan before anything is built:
- Turn on Plan mode, or say Write a plan first. Don’t build anything yet. Nothing changes until you approve.
- Ask for phases and steps, why each step matters, and what “done” looks like.
- Pin down anything vague, especially sizes, proportions and angles. Otherwise the agent has to guess.
- Say Implement, or Build it phase by phase, and check each phase.
I want to model a medieval knight for a game. Before building anything, write a detailed plan: split the work into phases, with steps and substeps, why each one matters, and how we’ll know each phase is done. Don’t build yet.
Build in pieces
Follow-ups build on what’s already in the scene. Start with the main shape, then add detail one change at a time:
- Create a medieval Gothic church for a fantasy RPG.
- Add a bell tower on the left and make the windows taller.
- Add stone materials and moss on the lower walls.
For complex models, build each part on its own, like the helmet, armor and sword, then ask to group them. Each prompt saves a checkpoint.
Many heavy operations in one prompt can freeze Blender, especially on slower computers. Split big jobs into several prompts.
Describe the result, not the steps
Give the details an artist would ask for:
- What: the object or change
- Style: realistic, stylized, low-poly
- Size and placement: “about 2 m tall, next to the desk”
- Count and naming: “four chairs named Chair_01 to Chair_04”
- Purpose: “for a Unity mobile game”, “for a close-up render”
- Measurements: “a 1.2 m wide window”, “20 × 15 units”. For real buildings or products, give real dimensions or attach a drawing.
| Instead of | Try |
|---|---|
| Make a house | Build a modern two-story house with a glass facade and a rooftop garden, about 10 m wide, centered at the origin |
| Fix the lighting | Make the lighting warm and soft, like late afternoon, and remove the harsh shadow on the sofa |
Let the agent work
3D-Agent inspects the scene, takes screenshots, checks the result and fixes what’s off. That loop is what makes it reliable.
Say what “right” looks like, and the agent checks it before it finishes:
Create a 4.6 × 4.8 m floor slab and four exterior walls, 2.7 m high. Check: no gaps at the corners and no floating geometry.
Give it references
- Type @ to mention an object, or select objects in Blender and say the selected objects.
- Attach a reference image and describe it in words too. Images, text and measurements together work best.
- Send one view per image. A sheet with many views confuses the agent.
- For real objects, ask for research first: Look up the real dimensions of a Vespa scooter, then plan the model.
- Attach a PDF or document, or add it to a project so every chat can use it.
For a consistent style, add a short .md file to a project with the colors, level of detail, polygon budget and naming. Every chat in the project reads it.
Set rules and limits
Say what to avoid, not only what to make:
- Don’t change my viewport settings or bone colors.
- Don’t use the Shrinkwrap modifier.
- Keep it under 10,000 triangles, and use only boxes and cylinders.
If a task could go more than one way, say which you want, or the agent picks: Prefer adding edge loops over smoothing the whole mesh.
If parts float apart or overlap, ask the agent to compare their positions, taking parent and child objects into account: Compare the placement of the floors and the railings using local and world coordinates, then fix the gaps.
Keep chats focused
Use one chat per task or asset. Every turn carries the chat’s history and screenshots, so long chats get slow. When you see This chat is getting heavy, start a new chat. Your Blender file and checkpoints carry over.
If the agent goes in circles, start a new chat and describe what you learned in the first one.
Write prompts in English for the most reliable results.