Focus Toolkit Documentation

Focus Toolkit

A Cinema 4D plugin for streamlined camera focus management with Octane Render support.

Author: Anlv ([Behance](https://www.behance.net/anlv))

Compatibility: Cinema 4D 2026+ with Octane Render

Overview

Focus Toolkit simplifies camera focus workflows in Cinema 4D. It creates, manages, and organizes focus objects for cameras, integrates with Octane camera tags, and provides a live-preview dialog for aperture and focal length adjustments — including Dolly Zoom (Hitchcock effect).

Quick Start — Modifier Keys

The plugin is activated as a single command. Hold a modifier key to access different modes:

None: Create or activate a focus object for the selected/render camera. Activates the Place tool.

CTRL: Select the render viewport camera and scroll to it in the Object Manager.

ALT: Open the Advanced Camera Tools popup menu.

SHIFT: Open the Camera Settings dialog (aperture & focal length with live preview).

Features

1. Focus Object Creation (Default)
   
   - Selects the active camera (or falls back to the render viewport camera).
   - If the camera already has a focus target, activates it and enters Place mode.
   - If not, creates a new Null object named <CameraName>_Focus, links it as the camera's target object, and enters Place mode.
   - Automatically creates an Octane camera tag if missing, sets autofocus off, and defaults aperture to 2.8 cm.

2. Camera Settings Dialog (SHIFT)
   A non-modal dialog with live scene preview:
   > Note: Aperture settings currently only work with Octane Render. Focal length and Dolly Zoom work with any renderer.
   - Aperture Presets (F-Stop): No Blur, F/1.2, F/1.4, F/2, F/2.8, F/4, F/5.6, F/8, F/11, F/16, F/22, F/32. (Octane only)
   - Custom Aperture: Manual input in cm. (Octane only)
   - Focal Length Presets: 8mm, 17mm, 24mm, 35mm, 50mm, 75mm, 85mm, 100mm, 135mm, 300mm.
   - Custom Focal Length: Manual input in mm.
   - Dolly Zoom (Hitchcock Effect): When enabled, changing focal length automatically repositions the camera to maintain the same framing/composition on the focus target.
   - OK / Cancel: OK keeps changes; Cancel restores the original aperture, focal length, and camera position.

3. Advanced Camera Tools Menu (ALT)
   A popup menu with two sections:
   
   - Focus Management
   Create New Focus Object: Sub-menu with two options: Delete Existing Focus (replace) or Keep Existing Focus (create alongside).
   Set Common Focus for All Cameras: Creates a single shared Common_Camera_Focus null and assigns it to every camera in the scene.
   Delete Current Camera Focus: Removes the focus object of the active camera.
   Delete All Camera Focus Objects: Removes focus objects from every camera in the scene.
   
   - Advanced Features
   Smart Focus to Selected Object Surface: Calculates the closest surface point of the selected polygon object to the camera and positions the focus object there. Falls back to object center for non-polygon objects.
   Add Target Tag to Selected Object: Adds (or updates) a Target Expression tag on the render camera pointing at the selected object.
   Add Target Tags for All Cameras: Adds Target Expression tags on every camera in the scene, all pointing at the selected object.
   Rename Camera with Focal Length: Renames selected cameras to <Name>_<FocalLength>mm. Updates existing suffix if present.
   Organize Focus (Move to Camera Child): Moves each camera's focus object to be a child of that camera in the Object Manager hierarchy, preserving world position.

4. Select Render Camera (CTRL)
   Sets the selected camera as the render viewport camera and scrolls to it in the Object Manager.

Octane Integration

- Automatically creates Octane camera tags (ID 1029524) when needed.

- Disables Octane autofocus and sets aperture via the Octane tag.

- Aperture presets calculate physical aperture size from F-stop and focal length: aperture_cm = (focal_length_mm / f_stop) / 10.