Imager Tonemap - Arnold User Guide
Use the tonemap imager to artistically modify the image's tone mapping using a Filmic or a modified Reinhard curve.
Both the Strength and the Length need to be different from 0, for the Toe and Shoulder to make a difference.
Input
Input points to the previous imager operation in the chain (so that you can stack them and apply multiple operations serially).
Enable
Enables this imager.
Layer Selection
Selects layers processed by this imager with a glob or operator expression. An imager can use a selection to determine whhich AOVs will be selected to be processed by the imager at render time. The selection is an expression that can consist of multiple selections concatenated by:
or(union)and(intersection)not(negation)and not(exclusion)()for nested scoping
Each selection uses glob patterns and regular expressions and a node will be processed by the imager if the expression matches the node name. By default, glob matching is used unless the selection is in a regex quote, i.e. r'<my_regex>'. For example:
specular or diffuse
not r'sss_(direct|indirect)'
r'color_(mask1|mask2)' or r'mask[34]'
Mode
Tonemap mode.
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| filmic (default) | reinhard | heatmap |
Filmic Toe Strength
Amount of curvature for the tonemap curve in the darker values.
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| 0 (default) | 0.5 | 0.9 |
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| 0 (default) | 0.5 | 1 |
Filmic Toe Length
Amount of darker values affected by the toe.
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| 0 | 0.5 (default) | 1 |
toe strength: 0.5
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| 0 | 0.5 (default) | 1 |
Filmic Shoulder Strength
Amount of curvature for the tonemap curve in the brighter values.
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| 0 (default) | 0.5 | 1 |
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Filmic Shoulder Length
Amount in f-stops of brighter values affected by the shoulder.
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| 0 | 0.5 (default) | 1 |
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Filmic Shoulder Angle
Curve slope when white is reached.
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| 0.1 | 0.5 | 1 |
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| 0 (default) | 0.5 | 1 |
Reinhard Highlights
Reinhard photographic tonemap operator strength.
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| 1 (default) | 0.5 | 0 |
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| 1 (default) | 0.5 | 0 |
Reinhard Shadows
Additional tone mapping control for darker values.
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| 0 (default) | 0.5 | 1 |
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| 0 (default) | 0.5 | 1 |
Lut Filename
Specifies the LUT file to load.
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| No LUT | LUT (.cube) |
Lut Working Color Space
It is possible to specify a working color space here to convert to the specified space, apply the LUT, and convert to linear or rendering color space again.
Preserve Saturation
Preserves color saturation for extreme bright values.
This is for values that are beyond 1, if you don't preserve saturation they go to white, otherwise, they keep their color.
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| Disabled | Enabled |
Gamma
Gamma curve exponent for midtones value control.
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| 1 (default) | 2.2 | 3 |
Mix
0 preserves the input untouched and 1 applies the full node effect.
Heatmap
Imager mode that creates a spectrum based on the looked-up AOV quantity. The color ranges from blue (at minimum) to red (at maximum).
Heatmap Min
Heatmap minimum value clamp.
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| 0 (default) | 0.1 | 0.2 |
Heatmap Max
Heatmap maximum value clamp.
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| 1 (default) | 0.5 | 0.25 |
Heatmap Input Mode
Interpretation of the incoming RGB color value.
- length: vector length of the RGB color values.
- min: minimum value of RGB components.
- max: maximum value of RGB components.
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| length | min | max |