# Transformation Constraint 自设变换约束

## 选项

Target 目标

By default, the Min and Max values bound the input and output values; all values outside these ranges are clipped to them. When you enable this button, the Min and Max values are no longer strict limits, but rather "markers" defining a proportional (linear) mapping between input and corresponding output values. Let us illustrate that with two graphs Fig. fig-constraints-transformation-extrapolate. In these pictures, the input range (in abscissa) is set to (1.0 to 4.0), and its corresponding output range (in ordinate), to (1.0 to 2.0). The yellow curve represents the mapping between input and output.

 禁用延伸: 输出值都被限制在 (1.0 至 2.0) 范围内。 启用延伸：输出值是按输入值等比例得出的 “自由”值。
Target/Owner

Controls the percentage of affect the constraint has on the object. See common constraint properties for more information.

### 源至目标的映射模式

Location, Rotation, Scale

X/Y/Z Min, Max

### 映射到

Location, Rotation, Scale

X/Y/Z Source Axis

The three axis selectors allow you to select which input axis to map to, respectively (from top to bottom), the X, Y and Z output (owner) axes.

The Min and Max number fields control the lower and upper bounds of the output value range, independently for each mapped axis. Note that if a min value is higher than its corresponding max value, the constraint behaves as if it had the same value as the max one.

Before Original (Rotation)现有值之前

The new rotation is added before the existing rotation, as if it was applied to a parent of the constraint owner.

After Original (Rotation)现有值之后

The new rotation is added after the existing rotation, as if it was applied to a child of the constraint owner.

Note

• 由于历史原因， 混合*模式在位置和旋转中默认为 *添加 ，缩放中默认为 替换

• 当使用目标的旋转变换属性作为输入，无论真正的值是什么，约束将始终"重置回" (-180, 180)范围。例如，如果目标绕 X 轴旋转420°，约束实际使用的 "X" 输入值将是：

$$((420 + 180) modulo 360) - 180 = 60 - ...$$

这就是为什么此约束不是真的适合齿轮 ！

• 类似地，当使用目标缩放变换属性作为输入，无论真正的值是什么，约束将始终使用其绝对值(即对负值取负)。

• 最小值 高于其相应的 最大值 时，两个值都会取为 最大值 。这意味着不能创建"反向"映射...