Hasta La Motion!

Shot a test scene in a studio with tracking markers on the wall at 1m intervals.
Tracked and solved in PFTrack, with correct filmback and lens focal length.
Scaled the scene in PFTrack, measuring between 2 points and making that distance 1m.
Exported from PFTrack as a Nuke scene, which opens nicely into Nuke, with a very nifty point cloud (of nulls) you can attatch to the scene file as reference.

Imported a Maya fbx of the yet-to-be-built sets, made lifesize, ie 1m is 1m.
BUT, I’m having to reduce the fbx to 20% of it’s size to apparently fit the PFTrack exported scene, not what I expected.
What ‘gotcha’ am I missing here, as in my mind the scales should match?
Is the PFTrack or Maya scene scale wrong?

thanks in advance

mike.c

i am currently trying to learn PFTrack, i started with motion capture, which i got it to work smoothly. what i’m having trouble with at the moment is camera tracking, i have the test objects sticking, which is good i guess, but then i could never get the grid to stick to the actual ground plane in the footage.

i used to think tracking a shot will require measurements of camera aperture and focal length, then i watched some dude track a shot with PFTrack on Youtube without the measurements, so i went and tried myself, but it’s not working.

can some one give me a definitive answer? do i have to have the exact measurement of camera aperture and focal length to track a shot?

thanks for you time.

Ding

Since this has been asked for some times now,
I just wanted to point out that there’s a new tip available on VFXPedia.
http://vfxpedia.com/index.php?title=…_Techniques#3D

(Yes…this message has been posted on PigsFly already,
but I figured one or the other of you folks might not be signed up there…;-))

So if you have saved an FBX or OBJ sequence out of your 3D application
and want to bring it into Fusion on a per-frame basis
this is how it works in Fusion5:

This assumes you have a sequence of FBX or OBJ like "MyMesh0000.obj, MyMesh0001.obj, etc.
and want to have MyMesh0000 at frame 0 and MyMesh0001 at frame 1 of your composition.

– Add an FBXMesh3D to your scene and load any of the meshes.
– Adjust the material of the mesh in the FBXMesh’s Material tab.
– Once this is done to suit your needs, add an animation to the materials
by right-clicking on any of the color sliders and selecting "Animate MaterialsStdInputs group".
This step is very important, because else on loading a new mesh all color values would be reset.

Now for the trick. Go to the FBXMesh’s Scripting tab and in the FrameRenderScript add the lines

MyPadding=4 –set the padding of your sequence
MyFrameNum=string.format("%0"..MyPadding.."d", time) –derive the framenumber from the current time in padded format
ImportFile="Comp:\\OBJ_SEQUENCE\\MyMesh"..MyFrameN um..".obj"

Most likely you would have to tweak the path to your needs.

That’s it.

Have Phun.

Eric.

http://www.youtube.com/user/GuardianShortMovie