Instance Method

setOpacity:atTime:

Sets the opacity value at a specific time within the time range of the instruction.

Declaration

- (void)setOpacity:(float)opacity atTime:(CMTime)time;

Parameters

opacity

The opacity to be applied at time. The value must be between 0.0 and 1.0.

time

A time value within the time range of the composition instruction.

Discussion

Sets a fixed opacity to apply from the specified time until the next time at which an opacity is set; this is the same as setting a flat ramp for that time range. Before the first time for which an opacity is set, the opacity is held constant at 1.0; after the last specified time, the opacity is held constant at the last value.

See Also

Managing Properties

- setOpacityRampFromStartOpacity:toEndOpacity:timeRange:

Sets an opacity ramp to apply during a specified time range.

- setTransform:atTime:

Sets the transform value at a time within the time range of the instruction.

- setTransformRampFromStartTransform:toEndTransform:timeRange:

Sets a transform ramp to apply during a given time range.