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# SCNMorpherCalculationMode

The interpolation formulas for blending between target geometries.

```
enum SCNMorpherCalculationMode
```

## Overview

A morpher computes its current surface by summing weighted geometry elements from the base geometry and all target geometries. The position of a vertex on the surface is produced by adding the position vector of a point on the base geometry to the position vectors of the corresponding points on all target geometries. The morpher’s [`calculationMode`](/documentation/SceneKit/SCNMorpher/calculationMode) property selects the formula used to calculate this sum.

If the mode is [`SCNMorpherCalculationMode.normalized`](/documentation/SceneKit/SCNMorpherCalculationMode/normalized), the position from the base geometry is weighted by one minus the sum of all target weights, as in the following formula:

```objc
Position = (1 - weight0 - weight1 - ...) * Base + weight0 * Target0 + weight1 * Target1 + ...
```

If the mode is [`SCNMorpherCalculationMode.additive`](/documentation/SceneKit/SCNMorpherCalculationMode/additive), the position from the base geometry is not weighted, and SceneKit uses the following formula instead:

```objc
Position = Base + weight0 * Target0 + weight1 * Target1 + ...
```

## Topics

### Constants

[`SCNMorpherCalculationModeNormalized`](/documentation/SceneKit/SCNMorpherCalculationMode/normalized)

Target weights must be in the range between `0.0` and `1.0`, and the contribution of the base geometry to the morphed surface is related to the sum of target weights. This is the default mode.

[`SCNMorpherCalculationModeAdditive`](/documentation/SceneKit/SCNMorpherCalculationMode/additive)

Target weights may take on any value, and weighted contributions for each target are added to the base geometry,

## Relationships

### Conforms To

[`RawRepresentable`](/documentation/Swift/RawRepresentable)

[`Equatable`](/documentation/Swift/Equatable)

[`BitwiseCopyable`](/documentation/Swift/BitwiseCopyable)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`Hashable`](/documentation/Swift/Hashable)

[`Sendable`](/documentation/Swift/Sendable)

---

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