Judah Mantell

Last Update a year ago

SceneForge Includes LUT and Color Correction 

Tools

As of version 0.6.15, a full color grading workflow window is available through both Stage and Shoot Mode.  You can take a look at the video above for more info, or read on for information about LUTs.

LUTs in SceneForge

Look Up Tables (LUTs) are files that contain information that tells the renderer how to display certain colors.  This is common functionality in video editors and other 3D programs.

SceneForge Supports two workflows when using LUTs:

.CUBE Workflow

Much like any other NLE or 3D software, SceneForge simply accepts .CUBE files for 3D LUTs.  These can be purchased from various vendors online, or created from scratch using a software like Lightroom or Resolve.

Image Workflow

SceneForge will technically read any PNG or JPG file as a LUT, but only correctly formatted ones will have the desired effect.
Rather than using three one-dimensional (1D) LUTs, a single 3D LUT is used.

In SceneForge these are read as a 32x32x32 LUT unwrapped into a 1024x32px Texture. They are created by taking a neutral LUT (below) and altering it to your desired look.

Creating Image LUTs

To start, make sure you have a Neutral LUT on hand.  You can download one from within the Color Grading window, or save and use the correctly-formatted Neutral LUT below.

If you were to apply this Neutral LUT, it would have no affect, but if you were to use a sepia-toned LUT, for example, your image would reflect that change.

See example below:

 (Source: Epic Games UE Docs)

To customize the Neutral LUT, open a camera snapshot in an image editor (Photoshop, in this example).

Then, apply any desired Image Adjustments you want to get the desired look.   (Adjustment Layers are the best way as they're easily moveable and non-destructive).

Then, simply apply those same adjustments to the Neutral LUT and save as its own image file. 

That LUT image will now contain the Image Adjustments you want and can be imported into SceneForge.

Unreal Engine uses a similar system and has a great guide on creating image LUTs in Photoshop.

(Keep in mind that UE uses 16x LUTs, while SceneForge uses 32x LUTs).

Trackball Color Control

Primaries Wheels:

You can control the Lift, Gamma, and Gain using trackball controls right within the existing color grading menu.

These follow the ASC CDL standard.  When you adjust the position of the point on the trackball, it shifts the hue of the image towards that color in the given tonal range.

You can use the different trackballs to affect different ranges within the image. Adjust the slider under the trackball to offset the color lightness of that range.

• Lift: Use this to control the dark tones. This has a more exaggerated effect on shadows.
• Gamma: Use this to control the mid-range tones with a power function.
• Gain: Use this to increase the signal and make highlights brighter.

Log Wheels:

These separately control the shadows, midtones, and highlights of the frame. Unlike Lift, Gamma, and Gain, you can use these to precisely define the tonal range for shadows, midtones, and highlights.

The slider below each wheel controls the offset of the color lightness.