SAM 3 object selection

Sogni runs SAM 3 image segmentation on the Sogni Supernet as a standalone job. Give it one original still and tell it what to select with click points, boxes, or a short text label. It returns one lossless PNG at the source's exact dimensions: a black-and-white mask (white is the selection) or, if you ask for it, the selection cut out on transparency.

SAM 3 selects; it does not generate. It never adds scene content, animates a subject, or preserves a person's identity from their name. Selection is deterministic for a given image and prompt, so changing the seed changes nothing.

#Workflow ID

#Product availability

• Sogni World: the first step of every new path, and Select anything inside the featured story worlds.
• Sogni API and SDKs: the exact model ID above. sam3Prompt points, boxes, and text are available from JavaScript SDK 5.31.0; applyMask, maxInstances, and negative boxes from 5.34.0.
• Sogni Creative Agent Skill: selects objects and cuts out subjects with the same model ID.

#Selection prompt

Coordinates run from 0 to 1 against the original image, with the origin at the top left. If your interface shows the image smaller, normalize the click within the displayed image and leave the uploaded original unchanged. Never send a cropped preview as the source.

Rules the SDK enforces before submitting:

• At least one point, box, or text prompt is required.
• Text and points cannot be combined.
• With points, you can add at most one box, and it cannot be negative.

A single point may select only part of an object, such as a lantern's flame or a car's window. For the complete object, add include points, use negative points on neighbors, or switch to a short text label with a box around the one you want. The box guides SAM; use the returned mask, not the box, for outlines and hit testing.

#Source requirements

• One PNG, JPEG, or WebP original. The result always matches the source's dimensions; width, height, steps, and guidance are ignored.
• Sogni World additionally requires each edge between 256 and 2560 pixels for paths.

#Pricing

SAM 3 is priced as one flat request, whatever the source size. Sogni shows the estimate before the job runs; call projects.estimateCost() for a live estimate in your own app.

#JavaScript SDK example

import { SogniClient } from '@sogni-ai/sogni-client';
import fs from 'node:fs';

const sogni = await SogniClient.createInstance({ appId: 'my-app', network: 'fast' });
await sogni.account.login('username', 'password');

const project = await sogni.projects.create({
  type: 'image',
  network: 'fast',
  modelId: 'sam3_image_segment_bf16',
  positivePrompt: '',
  numberOfMedia: 1,
  startingImage: fs.readFileSync('./original.png'),
  sam3Prompt: {
    points: [
      { x: 0.45, y: 0.6, label: 'positive' }, // inside the object
      { x: 0.12, y: 0.1, label: 'negative' }  // leave the sky out
    ],
    threshold: 0.5
  },
  outputFormat: 'png'
});

const [maskUrl] = await project.waitForCompletion(); // PNG at the source size

The completed job also reports how many selections were detected and returned, and each selection's score, normalized box, coverage, and whether it was included. Use them to tell a confident selection from a marginal one, or to spot that a text prompt matched more instances than you expected.

#Using the result

• Inspect the mask at full size before relying on it.
• Keep the original still. Use the mask as a selection guide for an editing model that accepts it, such as a context image for Krea 2 Identity Edit. A guide does not guarantee that every pixel outside the selection stays fixed, so check the whole result.
• Sogni World uses the mask as both the clickable outline in a scene and the guide for creating the next scene.