Models, quality, credits, and daily limits

Every render has a model, model-specific output settings, and an image count. CAD Scene shows the total credit cost before you send.

Choose a model

A project has a default model. New Composer sends start with that model. Changing the model for one send does not change the project default. Changing the model resets its Quality, Resolution, and Aspect to that model's defaults.

Nano Banana 2 is the app default for new or unset selections. Its native defaults are 2K Resolution and a 3:2 Create Aspect. Existing app-wide and project defaults keep their saved model.

Four models are currently available.

Nano Banana 2

• Supports Create, Enhance, and Edit.
• Supports Composer references in all three modes.
• Offers 512, 1K, 2K, and 4K resolution.
• Offers the widest Create aspect-ratio range.

Nano Banana Pro

• Supports Create, Enhance, and Edit.
• Supports Composer references in all three modes.
• Offers 1K, 2K, and 4K resolution.
• Offers the conventional Create aspect-ratio range.

Nano Banana

• Supports Create, Enhance, and Edit.
• Supports Composer references in all three modes.
• Uses a fixed 1K resolution.
• Offers the conventional Create aspect-ratio range.

GPT Image 2

• Supports Create, Enhance, and Edit.
• Supports Composer references in Create and Enhance.
• Does not accept Composer references in Edit.
• Offers Low, Medium, and High provider quality.
• Offers 1K, 2K, and 4K resolution.

Model capability is a compatibility choice. CAD Scene does not promise that one model is always faster or visually better.

Controls and limits follow both the selected model and the active mode. In Edit, the model capability sets the maximum number of named regions. Every current selectable model supports eight. CAD Scene reads that value from the model registry, so a future lower-cap model will update the canvas, Send requirements, Render again, and Create variations without a separate hardcoded limit.

Changing to a lower-cap model would preserve existing regions and state the exact number to remove before Send. You could remove regions or choose a compatible model. Render again and Create variations would mark an incompatible model unavailable instead of trimming the stored mask metadata.

Quality and cost

The model list is always visible in the render settings popover. Fine settings sit under a collapsed Settings disclosure. Open it to review the current selection.

CAD Scene hides a control when it has only one possible value. Nano Banana's fixed 1K Resolution is recorded without showing a one-choice control.

Gemini models expose Resolution, not Quality. Their cost can change with Resolution. GPT Image 2 exposes both provider Quality and Resolution. Either setting can change its cost. Selectable Resolution defaults to 2K. GPT Image 2 Quality defaults to Medium.

GPT Image 2 2K and 4K outputs are experimental. Their provider support may change.

Create aspect

Create shows each supported aspect ratio directly. There are no orientation groups. The default is 3:2 when that ratio is available.

Ratio availability changes with the model. A ratio tooltip shows the expected requested dimensions for the current Resolution. The final Output size can differ from that request.

Enhance and Edit size

Enhance and Edit do not show Aspect. They preserve the source proportions while applying the selected Resolution.

OpenAI may round the requested dimensions to a valid provider size. Generation details records the Requested size and measured Output size separately.

Changing models resets the output settings to that model's defaults. Review the Settings disclosure after every model change.

The Composer is the source for the exact current cost. It calculates the per-image rate from the selected model, Quality, and Resolution. Image count multiplies that rate. The preview updates before submit, including inside Render again and Create variations.

The popover header shows a compact total such as 5cr. This means 5 credits for the current image count. The resting Composer bar does not show a cost.

The free 4K upscale is a separate Lanczos resize. It does not create another provider generation or change the original render settings.

Project defaults

The Default model in app-wide Settings applies only when you create a new project. The new project stores that model with its current native defaults.

Each project's Default render settings then control new Composer sessions in that project. They store the model, Quality when supported, Resolution, and Create Aspect.

Composer changes last for the current session. They do not rewrite project defaults. An unavailable saved model switches to the product default and shows a notice.

Credits and limits

Render credits are charged when the send is submitted. One send with multiple images creates one charge equal to the per-image rate multiplied by the count.

Generate Composition and Generate one field have fixed costs. Each action shows its current cost before confirmation. Lanczos 4K upscale is free.

Create variations, Render again, retries, and Modify, Relight, or Effects operations submit new Renders. They use the normal per-image rate for the model and settings resolved by that action.

Credits and rolling daily limits are separate checks. Having enough credits does not bypass a limit.

Current rolling 24-hour limits are:

• 1,000 render submissions.
• 1,000 Composition generation requests.
• 1,000 field generation requests.

The render limit counts submissions, not output tiles. A single send with several parallel images uses one render-submission quota entry. It still charges for every image.

When a limit is reached, CAD Scene reports the estimated reset time. Wait for the rolling window or contact support for a higher cap.

Refunds

Failed and successfully cancelled render jobs refund their charged credits. Each output image has its own job and refund record. A failed tile does not cancel or refund its successful siblings.

Composition and field generation debit before the provider call. A provider or response failure refunds that operation.

Retry, Retry with model, Render again, Create variations, Modify, Relight, and Effects are new submissions. They create a new charge. A refund for the failed original does not make the replacement free.

An insufficient-credit rejection does not create renders or jobs. The transaction is rolled back.

When credits are the only remaining blocker, CAD Scene keeps the blocked control and opens the available plans and top-ups. A completed return is verified before confirmation appears. Stripe must report it as paid or no_payment_required. Continue returns to the original control. It does not submit the action automatically.