OCIO Layer

The OCIO layer is an effect layer that applies a stacked list of OCIO transforms in an optimised manner. All supported OCIO transform types can be created, configured, and stacked to achieve a customised colour pipeline as needed.

Note

For most simple cases we recommend using the standard OCIO workflow with an OCIO field on each component (e.g. Input transform in Video layer or Output transform in Display). See OCIO for further details.

Workflow

Effect layers receive their source from other layer types - either content or generative - through arrows. An arrow connects a source layer to a destination layer; the source layer is said to be “piped in” to the destination Effect layer. For more information on arrows, see the compositing layers topic.

To draw an arrow between two layers, hold down ALT and left-click & drag from the source layer to the destination layer.

1. Add an Effect layer to your track. For more information about adding layers, see creating layers.
2. Draw an arrow from your content layer to the Effect layer so the compositing order looks something like the following image. A Video layer piped into an Effect layer on the timeline.
3. Adjust the Effect layer properties to achieve the desired result.

OCIO layer properties

OCIO transforms

The list of OCIO transforms to define the colour pipeline can be configured here. The order of the transforms matters, and it is bottom-to-top (the bottom of the list is applied first, and the top of the list is applied last). Each transform shows the order by index number as a prefix of the transform name, and the transform type is added as a postfix (e.g. 1. myTransform [ColourTransform]). The transform is a Resource type, so you can create one and reuse it across other OCIO layers. Stacking duplicate OCIO transform resources in the OCIO layer is also allowed.

InputTransform

InputTransform applies a colour transform from the selected Input transform colour space into the currently selected Working space in the OCIO config (see OCIO Configs).

• Input transform: the source colour space to transform from.

OutputTransform

OutputTransform applies a colour transform from the currently selected Working space into the selected Output transform colour space in the OCIO config (see OCIO Configs).

• Output transform: the destination colour space to transform to.

ColourSpaceTransform

ColourSpaceTransform applies a colour transform from the Source colour space to the Destination colour space.

• Source colour space: the source colour space to transform from.
• Destination colour space: the destination colour space to transform to.

LookTransform

LookTransform applies a creative colour transform using a defined look from the OCIO config file. A look modifies the appearance of an image in a creative way, rather than performing a technical colour space conversion. It typically works alongside a viewing transform. For example, a look could be a neutral grade applied to film scans before VFX work, or a per-shot grade chosen by the director.

See: OCIO’s Looks Example

• Source space: source colour space to transform from.
• Destination space: destination colour space to transform to.
• Look transform: look transform to apply.
• Transform forward: transform from source space to destination if enabled, reversed direction if disabled.
• Skip colourspace conversion: skip the colour space transform if enabled.

NamedTransform

NamedTransform provides a set of colour transforms that are independent of the colour space being processed. For example, a utility curve transform where there is no need to convert to or from a reference space.

• Named transform: the named transform to apply.
• Transform forward: apply transform forward if enabled, inverted if disabled.

LutTransform

LutTransform allows applying a LUT between other OCIO transforms. The LUT file can be located like any other LUT in Designer (see LUT Layer). In addition to the traditional interpolation method of the LUT Layer in Designer, LutTransform offers various OCIO-supported methods.

• LUT transform: the LUT to apply, discovered from objects/LutFile
• Transform forward: apply LUT if enabled, apply inverse LUT if disabled.
• Interpolation: interpolation method to use:
  • Nearest: nearest neighbour
  • Linear: linear interpolation (trilinear for Lut3D)
  • Tetrahedra: tetrahedral interpolation (Lut3D only)
  • Cubric: cubic interpolation (not supported)
  • Default: the default interpolation type
  • Best: the ‘best’ suitable interpolation type

OCIO Transforms Lists

The OCIO transform table can be used to visualise and edit the list of OCIO transforms. There are a few actions you can use to edit your colour pipeline:

• Swap the order by dragging the transforms.
• Open the OCIO transform widget by right-clicking the row.
• Edit the transform element (e.g. source colour space) by left-clicking the field.
• Add a new OCIO transform by clicking OCIO transform +.
• Remove an OCIO transform by clicking the trash button -.

Common Layer Properties

Blend Mode

BlendMode controls how the output of the layer is composited with the layers below. Layers are rendered in a bottom-up order: layers at the top can modify the output of the layers below.

Changing brightness of a content layer in Designer is actually controlling the value of the alpha of the layer. Even when displaying a HAP video, the software will composite the layer with a controllable layer of alpha - one per layer.

There are two ways of expressing alpha in an image:

Straight alpha is an alpha channel which functions just like RGB. Alpha acts as a fourth channel of information per pixel which is as independent of the other three as R, G and B are of each other. For example, with straight alpha it is possible to have RGB = 255 (white) and alpha = 0 (fully transparent) on the same pixel. Internally generated content, such as gradient layer, are generated with straight alpha. This is the preferable style of alpha and considering the cleaner method of the two.

Premultiplied alpha takes the alpha and applies it to the values of the RGB channels per pixel. The more transparent something gets with premultiplied alpha, the closer it gets to black - as if the content is sitting on a black table. Premultiplied is the default output of Adobe Photoshop or AfterEffects. The result is our pixel at 255 RGB (full white) with 0 alpha would be calculated as a black pixel in the final image.

Here are explanations of what each individual blend mode will do.

Over

Makes a layer fully opaque. Premultiplies all alpha onto the RGB value of each pixel. Alpha = black, so adjusting the brightness of a layer in Over blend mode makes it darker.

Alpha

Default blend mode. It will apply alpha values as a transparency if the alpha is present. Brightness changes will make the layer more or less transparent.

Add

Adds the value of each RGB pixel together. Always creates a brighter result. Values clamp at 255.

Multiply

Reads the level of each subpixel as a level between 0.0 and 1.0, and multiplies source with blend. The result is always a darker image overall. For example: white x grey = 0.5. White turns transparent, black takes precedence. Alpha is applied in the same fashion as the Over Blend mode.

Mask

Applies a mask to the above layers in the stack with the same mapping. See Mask blending for more information.

Luma-Matte

This mode creates a Luma Matte by using a layer’s Rec. 709 luminance to control the alpha channel of the layers above it within the same mapping.

To determine transparency, the system calculates a weighted average of the red, green, and blue channels for each pixel. This resulting luminance value is then mapped as the alpha (opacity) value for the corresponding pixels in the upper layers.

As a result, white areas render the layers above fully opaque, black areas make them fully transparent, and gray values create proportional semi-transparency. This is a specialized Mask blend mode; for more details on the underlying logic, see Mask blending.

Inv-Luma-Matte

The Inverse Luma Matte mask works the same as the Luma Matte mask but the transparency is inverted so that white regions are transparent and black regions are opaque.

Multiply-Fade

The same as Multiply, but will make use of the alpha channel to calculate transparency in the source and blend layers. Since maximum transparency is premultiplied, alpha results in black. This will ignore black created through premultiplying.

Multiply-Alpha

Multiply with straight alpha. This mode assumes that the alpha has not been premultiplied onto the RGB values and will not apply a correction to the semi-transparent pixels.

Premultiply Alpha

Like how Multiply-fade will ignore the darkening caused by premultiplying, this blend mode will do the same with Alpha.

Colour Burn

Blend mode increases the contrast to darken the base colour while reflecting the blend colour. The darker the blend colour, the more intensely the colour will be applied in the base image. White as the blend colour produces no change. Using the colour burn blend mode can produce some harsh results at full opacity. The colour burn blend mode can be used to make tonal and colour adjustments to a layer.

Screen

This blend mode looks at each channels colour information and multiplies the inverse of the blend and base colous. The result is always a lighter colour. Screening with black leaves the colour unchanged. Screening with white produces white. The effect is similar to projecting multiple images on top of each other - where bright white is fully opaque, black is fully transparent and 50% grey is 50% transparent.

Overlay

Multiplies or screens the colours, depending on the base colour. Patterns or colours overlay the existing pixels while preserving the highlights and shadows of the base colour. The base colour is not replaced, but mixed with the blend colour to reflect the lightness or darkness of the original colour.

Hard Light

Multiplies or screens the colours, depending on the blend colour. The effects is similar to shining a harsh spotlight on the image. If the blend colour (light source/top layer) is lighter than 50% grey, the image is lightened as if it were screened. This is useful for adding highlights to an image. If the blend colour is darker than 50% grey, the image is darkened as if it were multiplied. This is useful for adding shadows to an image. Painting with pure black or white results in pure black or white.

Soft Light

Darkens or lightens the colours, depending on the blend colour. The effect is similar to shining a diffused spotlight on the image. If the blend colour (light source/top layer) is lighter than 50% grey, the image is lightened as it if were dodged. If the blend colour is darker than 50% grey, the image is darkened as if it were burned in. Painting with pure black or white produces a distinctly darker or lighter area, but does not result in pure black or white.

Darken

Looks as the colour information in each channel and selects the base or blend colour - whichever is darker - as the result colour. Pixels lighter than the blend colour are replaced and pixels darker than the blend colour do not change.

Lighten

Looks at the colour information in each channel and selects the base or blend colour - whichever is lighter - as the result colour. Pixels darker than the blend colour are replaced and pixels lighter than the blend colour do not change.

Difference

Looks at the colour information in each channel and subtracts either the blend colour from the base colour or the base colour from the blend colour depending on which has the greater brightness value. Blending with white inverts the base colour values and blending with black produces no change.

Exclusion

Creates an effects similar to but lower in contrast than the difference mode. Blending with white inverts the base colour values. Blending with black produces no change.

Colour Dodge

Looks at the colour information in each channel and brightens the base colour to reflect the blend colour by decreasing contrast between the two. Blending with black produces no change.

Hard Mix

Adds the RGB channels of the blend colour to the RGB values of the base colour. If the resulting sum for a channel is 255 or greater, it receives a value of 255; if it is less than 255 it receives a value of 0. Therefore all blended pixels have RGB channels of either 0 or 255. This changes all pixels to primary additive colours (RGB), white or black.

Brightness

This property (which appears as a light bulb icon) controls the brightness of the layer output.

If the layers blend mode is set to Alpha, then reducing the brightness to 0 also reduces the opacity of the layer to 0. This can be useful when you want to dissolve from one layer to the next. In that case, you can place the new layer above the old layer and increase its brightness level.

Note

Layers that are patched to Sockpuppet (DMX, OSC or HTTP) are made Dormant when their brightness is set to 0. This means they will not do any rendering or consume any resources until their brightness is changed to > 0. You can find more information about this here: Sequencing with Sockpuppet. Layers without a sockpuppet patch do not behave in this way.

Mapping

The mapping property controls how the layer output is mapped onto the screen(s) in the Stage level.

For information on mapping, including how to use the different mapping types offered by Designer, please see the chapter Content Mapping