Obtain start time for specified layer

[AnmolM]

EDIT :- Having rethought the approach, how can I save image data across calls to Render() ? My data is generated and overlaid onto a layer. So I don't want to access a layer in the previous frame, but my image information (basically the alpha channel that I generated).

Hi. I've gone through the docs, and I dont see a way to obtain the start time for a layer. in_data provides a way to get current_time, time_step, total_time, local_time_step and time_scale

However it also mentions that

>>

. If a layer starts at other
than time 0 or is time-stretched, layer time and composition time are distinct.
The current frame number is current_time divided by time_step. The
current time in seconds is current_time divided by time_scale.

>>

So layer can start at non zero time, how do we figure that out?

P.S. I want to start a plugin at start layer time + 1. and then have the user specify the length of the effect.

[Rick Gerard]

I'm not sure what you are asking? Are you trying to create a script that automates a render?

If you are trying to access a property from another layer and use that property at a later time you can use an expression. The start time of a layer can be retrieved by just using inPoint

If you want to offset the value of a layer below but offset it by the time difference you can use valueAtTime(time - in Point);

Expressions can only be added to properties that can be keyframed.

Explain exactly what you are trying to do and maybe we can help.

[AnmolM]

Hi Rick. I am developing a plugin using the AE SDK. It generates an animation that requires the previous frame data. I tried this..

if (in_data->current_time)
ERR(PF_CHECKOUT_PARAM(in_data,Spirograph_INPUT,in_data->current_time-in_data->time_step,in_data->time_step,
in_data->time_scale,&temp_param));
else
ERR(PF_CHECKOUT_PARAM(in_data, Spirograph_INPUT, in_data->current_time, in_data->time_step, in_data->time_scale,
&temp_param));

Do Stuff to temp_param...

ERR(suites.WorldTransformSuite1()->copy(in_data->effect_ref, &temp_param.u.ld, output, NULL, NULL));

As such, the first frame of active layer should be processed and copied to output. Then each successive call to render should have the new pattern overlaid on top of the previous one thus generating an increasing pattern by animating the size.

I am not seeing the increasing pattern, I only see one pattern per frame.