Thea Darkroom

Darkroom is Thea Render's IPR window, which provides a fast preview in Interactive and Production rendering. It can be used to configure the Display Settings as well as the Denoiser options (in case of production rendering).
Thea Darkroom window consists of the menu bar, rendering controls, Render Image, progress bar and display settings.

Darkroom Menu Bar


  • Save: Saves Darkroom Image in selected format.
  • Send to Picture Viewer: Launches the Picture Viewer and copies the image to it.
  • Block size: Once Interactive Render starts, the initial image consists of small square blocks. By increasing their pixels, these blocks are now bigger and working with IR while editing your scene is faster, but may offer a lower viewing quality
  • Enable SuperSampling: The IR image is produced with Super Sampling.
  • Enable Termination Criteria: Enables Termination Criteria in Interactive Rendering. The same values as in Render Settings > Thea Render > General > Termination are used.
    Here you can choose whether you want to hide the different areas of Darkroom.

Render Controls


  • Starts rendering
  • Stops Rendering

Causes the scene to be retransferred to the engine. That means the next time you render, the whole scene will be reconverted from scratch.

Render Mode
Allows you to switch between Interactive and Production modes.

Render Engine
Image Resolution: Sets the default camera’s resolution based on the selected option.

  • Fit to darkroom: The camera resolution will be equal with the size of the Darkroom image.
  • Custom: The width and height that is set in Render Settings > Thea Render > Output will be used as camera resolution/
  • Any other constant values: Sets the limitation to the resolution of the camera to the selected width and height (e.g. 1920x1080)

Interactive Render Controls
These controls are visible and functional only in Interactive Mode.

  • Pick focus: Sets the Camera's focus distance based on the clicked position in the Darkroom Image.
  • Pick material: Sets as active the picked material.
  • Render Region: Allows to create and modify the Interactive Render Region in the Darkroom Image. To create a render region, hold left click and drag & drop anywhere in the Darkroom Image. To modify the region, drag the handlers in the corners of the region. If you double-click anywhere in the Darkroom Image, the render region will be disabled. The minimum Render Region is 32x32 pixels.

Production Controls

These controls are visible and functional only in Production Mode. They are synchronized with the corresponding parameters in Thea Render Settings.

  • Time limit: Sets the time limit. Format example: 1h 15m 30s. Use 0 for infinite.
  • Sample limit: Sets the sample limit.

Send to Picture Viewer
Launches Picture Viewer and sets its image from the Darkroom.

Save Image
Saves Darkroom Image.

Refresh Image
Retrieves the last generated image from the engine.

Darkroom Image
This is the area that hosts the image produced by the engine during rendering. In Interactive mode, the image is refreshed automatically every 100ms, while in Production mode it is refreshed once every second.

Camera Controls
In this area you can also apply camera manipulation commands as happens in Cinema 4D's viewport.

  • Pan: Hold Alt + Mouse wheel and drag the mouse.
  • Rotation: Hold Alt + Left click and drag the mouse.
  • Zoom: Hold Alt + Right click and drag the mouse. Alternatively, you can hold Alt and use the wheel up and down to zoom in and out.

Progress Bar
These controls are updated by the engine on rendering.

Time elapsed
This field shows the passed time in seconds.

Shows the rendering state.

Shows the progress per render pass.

Display Settings
These settings are used to configure Thea's active camera display settings. On modification, they are automatically transferred into the engine, refreshing the Darkroom Image accordingly.

There are three Tonemap methods that can be applied to the image: Standard, Reinhard Global/Local and Filmic.

  • Standard: No Tonemapping is applied.
  • Reinhard Global/Local: Reinhard Global performs great for low contrast images while Reinhard Local, on the other hand, produces images of higher contrast. Both methods respect the chromaticity of the image (color hue & saturation) while adjusting the brightness of each pixel.
  • Filmic: It provides better control over the Highlights and Shadows of the image while giving a photographic look. With this Tonemap method, it is possible to increase the overall exposure of the scene without losing details or overburning the highlights.

These options refer to denoising and as we have described above they are functional only in production mode. The Enabled parameters are used to switch the denoising effect on and off. Denoise Strength and Denoise Details affect only Non-Local Means.