Merging Contexts

[tony]

Hi,

I'm trying to make a custom version of the trail sop and I'm struggling to get my head around one bit. I've figured out how to evaluate my geometry at different times thanks to the TimeCompare example, but what I want to do is be able to merge multiple contexts, so I can have the geometry from my current frame and the geometry from a different frame all together. Here's my code so far:

SOP_myTrail::cookMySop(OP_Context &context)
{
fpreal t = context.getTime();
fpreal new_t;
OP_Context second_context = context;

// This is the frame number we want to evaluate
new_t = FRAME(t);

// The context takes seconds, not frame, so we convert.
new_t = OPgetDirector()->getChannelManager()->getTime(new_t);

// Adjust our cooking context to reflect this
context.setTime(new_t);

//Same again but with second context and 1 frame before
new_t = FRAME(t);
new_t-=1;
new_t = OPgetDirector()->getChannelManager()->getTime(new_t);
second_context.setTime(new_t);

*****************************************************************************
context+=second_context
*****************************************************************************

//Lock the input context
if (lockInput(0, context) >= UT_ERROR_ABORT)
return error();

// Duplicate our incoming geometry
duplicateSource(0, context);

unlockInput(0);
}
[/CODE]

The bit with the stars around is where it errors. I'd be very grateful for any advice.

Cheers

Tony

[Guest mantragora]

I don't know the answer but there is a an example "of an implementation of the Object Merge SOP" in HDK help. It may give you some ideas about merging multiple gdp into one.

[Guest mantragora]

I got it. Below full operator implementation with hip file.

Source Code:

http://www.mediafire.com/download/h6u9mb1d5vlfaeu/SOP_MergeTwoSourcesWithTimeOffset.zip

Edited February 19, 2014 by mantragora

[tony]

Thanks for pointing me in the direction of that example, it's really useful.

Your mediafire link doesn't seem to be working though?

Cheers

Tony

[Guest mantragora]

Hmm, just tried it and it works.

[tony]

Sorry my mistake, it is working fine. That's exactly what I was after, thank you.

Cheers

Tony