Edit

Edit changes labeled parts of an existing image. The source, marked regions, and region labels are required. The global prompt is optional.

Choose a source image

Select Edit, then choose the image under Image to edit.

You can:

• drop or select an image from your device;
• choose a render or upload already in CAD Scene;
• use the latest successful render.

The selected image is the source that Edit modifies. A composer reference image is only extra visual guidance. Read Image roles and source-image preparation before choosing a difficult source.

Changing the source clears the current canvas and marked regions. Choose the source before painting.

Mark a region

Use the image tools to identify every area that may change.

• Rectangle marks a rectangular area and is selected by default.
• Brush paints a freeform area.
• Eraser removes painted mask pixels.
• Undo and Redo step through mask changes.
• Clear all removes every marked region after confirmation.

The brush-size control changes the Brush and Eraser width. Nearby strokes can join into one region. Each detected region gets one dashed outline and one label field.

An Edit can contain up to eight regions. At eight, Rectangle and Brush stop adding regions. Eraser, Undo, and Clear all remain available. Delete or undo a region to continue.

Static example: Mark a tight rectangle around each intended change and give each region one concrete result label. Only marked areas belong to the Edit.

On larger screens, keep the Edit panel open when sending. Closing it removes the active canvas from the page, so CAD Scene asks you to reopen and review the regions.

Label each region

Every marked region needs a non-empty label. Describe the intended result, not the drawing action.

Useful labels are specific:

• replace the paving with dark basalt setts
• add a slim black steel window frame
• change the chair upholstery to olive wool

Avoid labels such as fix this or make better. They do not identify the material, object, or change.

The Composer's global prompt is optional. Use it only for guidance shared by all marked regions. If any label is empty, Send focuses the first empty field and lists the missing requirement.

What remains unchanged

Edit sends the source with a mask. The render request instructs the model to modify only mask pixels. It also instructs the model to preserve camera, perspective, framing, overall composition, and the existing photographic style.

Generative image models can still introduce small differences. Keep regions tight and labels concrete. Review the unmarked edges before accepting a result.

Edit instructs every model to preserve the source composition and aspect ratio. This instruction does not guarantee the original pixel dimensions.

For Gemini, quality selects a supported 1K, 2K, or 4K output resolution. CAD Scene does not send exact width and height to Gemini. GPT Image 2 may round or scale the source to valid dimensions. The composition-preservation instruction still applies.

Composer references in Edit are supported only by Gemini models. OpenAI Edit uses the source and mask only, so its reference control is disabled. Gemini Edit accepts up to five composer references.

How to review an Edit

Read an Edit comparison in three states. Start with the original source. Next, map each region label to its marked outline. Last, compare the result inside those boundaries.

Check the unmarked edges separately for drift. A sound result follows every region label while leaving the surrounding image stable.

Static example: Review the source first, then the marked outlines and labels, then the result. The final frame should change the marked areas while the surrounding camera, framing, and scene remain stable.

For a missing source, region, label, or open panel, see Troubleshooting and recovery.