Hi all, I sort of feel that I should be paying a fee for the amount of questions I ask on this forum! Anyway, until the bill arrives I was wondering if anyone had experience with loading camera data from PFTrack? I've used Boujou in the past without any problems, it just creats a .hip scene file. However, PFTrack exports as a .clip file and creates a geo file. Can't figure out how to get the info into Houdini. Any ideas?

Kindest regards,

JT

Hey Jon,

You read in the .clip file with a File CHOP which you export to a camera. I'm not sure what the .geo file is for but read that in with a File SOP. Maybe it's a ground plane or geometry for reference?

Cheers!
steven

Hi Steven, thanks for the reply. I followed your instructions. The file reads in fine though CHOPS, but I'm having a few issues exporting to the camera. I've checked the export flag on the file CHOP but what do I do from there?

Many thanks for your help.

JT

The chop doing the exporting needs two things to add up to a valid path to the node:

- exort prefix
- channel name

The export prefix is in the Common folder of all Chops. The channel name is what you inherited from the channel file. MMB on the icon of the Chop you are exporting to see the names. If you add the export prefix and the channel name, do you get a match? The slash between the export prefix and the channel name is added in for you.

The only way to change a channel name at this point is with the rename chop although if the external tool is working, this should be fine.

You know you have a successful export when you MMB on the Chop and you see to the right of each channel an export path added.

Hi Jeff thanks for the reply.

Sorry to be a pain but you lost me a little back there. This is my first time using CHOPS.

In the file CHOP, in the file tab, the “Name Options” is set to ‘Use name in file’.

Underneath the ‘name’ icon is greyed out but the field reads ‘chan0’.

In the common tab, the the ‘Export prefix’ reads ‘/obj’.

When I MMB on the CHOP, the Full Name is /ch/ch1/file1

I don't quite understand what you mean when you say

“If you add the export prefix and the channel name, do you get a match?”

Thanks for all you help.

JT

When you MMB on the CHOP icon, you should see three main areas in the info separated by two horizontal bars:

Top Section displays the path and the name of the chop.
Middle Section shows the channel information
Bottom section shows the actual names of the channels, their start-end conditions, min and max range, current value, and finally if successfully exported, the export path.

It is the bottom section you should be interested in. This is where the names of the actual channels you are exporting. You do NOT export the CHOP Operator. You export the channel(s). This is much different than channel referencing where the Operator name figures in to the equation. If you use a Rename CHOP and resolve the channel name to take /obj as the export prefix, all subsequent CHOPs become the export CHOP. I tend to always use a null CHOP or a Rename CHOP as the export CHOP so I can rewire above at will.

Hi Jeff, really sorry I’m still not entirely with you, so would that mean that I have to export each relevant channel individually though separate rename CHOPS? Should the prefix be set to /obj in all chops? I understand the breakdown when you MMB on the file chop, i'm just still not sure how to export the channels. Bit new to this.

Thanks

Regards,

JT

If all the channels in the CHOP resolved to proper targets, then a single CHOP would be required to export all the channels that it contained. Once again as long as the path matches.

It might be best just get a simple export going. Take a wave CHOP and leave it to default to chan1.
Follow with a rename CHOP and rename * to model/ty.
Now given that the default export prefix is /obj, turning on the export flag will now export the channel /obj + model/ty properly to the parameter /obj/model/ty.

Now go back to the wave CHOP and in the Channel folder put in chan which will create three channels called chan1 chan2 and chan3.
Now in the rename CHOP, change model/ty to model/tx model/ty model/tz. You could also put in model/t which would resolve to the same thing.

Take a look at the help for the rename CHOP to see how to use wildcards and characters to create patterns to rename groups of input channels to properly match up your target node(s).

Getting something simple to work usually helps getting something complicated sorted out.

Thanks Jeff, that help. I get how the channels are exporting now. The rename CHOP is displaying the Error: This CHOP has no effect. I followed your instructions, but i'm not recieving a successful export. Sorry, I really appreciate your help.

JT

hey JonT

basically the bgeo file is a point cloud of the exact points u tracked ur track.
so if u bring it in with a file sop and show points, they will line up exactly the same in ur pftrack scene.

then its crucial that u export in this order from ur chops onto ur camera.
once bringing it in with a file chop, make sure that the sample matches ur fps.

tx ty tz rx ry rz px py pz sx sy sz aperture focal resx resy aspect roll

or else ur variables get swapped out and cause wierd errors.

in my experience, i havent had to rename any channels etc,
its pretty simple, file chop and export chop

hope this helps



btw, i love the integration and it works really well so if u have any problems, please let me know and will help u.

anyways

all the best

aracid