i want to understand how a video was created with houdini–i am a student playing around with 3d concepts ( i know bryce faily well)

its on the houdini site but cannot find it again
its a crowd of people in a university coutyard playing with what looks like a sizzler–throwin it from student to student–see if my knowledge on how this was made is close.

one –create a video of individual persons throwing and catching things–or a group of persons throwing and catching things–all against a flat background–white, blue or green–not to important.
two–bring this video into houtini–mask out the background–create a layer and a put a image of a gothic university court yard.
three–now we have a background layer and a video layer.
four–create a sparker with a particle generator–so it is like a sphere–also create a line and use that as a emiter for a sparker effect–this is also a layer.
now somehow have all the individual frames of the video on some sort of a timeline

place the sparkler/line image and keyframe it to various persons in the crowd

any direction would be really helpful
peter

It sound slike that was a Harry Pott(head)er customer story. But I think its inaccesible now. Couldn't find it either, but I can recall seeing it on SESI pages.

For your break-up…
You don't neccesarily need to take different background plates for your actors and the background. You can do it in one real plate, if you can film on the real location, then motion track, import camera data to your 3D app, generate our particle stuff, and thats it, almost… Needs some post maybe to get reflections/lighting feedback onto the actors, and you're done.

(Any PROs 'round to correct me, please ?)

WhoDjini
It sound slike that was a Harry Pott(head)er customer story. But I think its inaccesible now. Couldn't find it either, but I can recall seeing it on SESI pages.

For your break-up…
You don't neccesarily need to take different background plates for your actors and the background. You can do it in one real plate, if you can film on the real location, then motion track, import camera data to your 3D app, generate our particle stuff, and thats it, almost… Needs some post maybe to get reflections/lighting feedback onto the actors, and you're done.

(Any PROs 'round to correct me, please ?)

It''s there, on the latest SESI demo reel.

One thing to consider is how heavy this ball of sparks would be. It's always better to give actors real things to play with, but the cost of it is that you will need to deal with it in post, removing it from hands for example.

Another step would be to give them source of light, so you won't have to deal with light casting in composition, although I bet in 95% of cases, people fake emitted lights by mask and CC. This would require tests but I have a feeling that a light ball with some specific bright color (to correct in post), would add additional value (or trouble, you never know unless you try ).

In general, yes, this is a path: shoot (with prop), track camera, generate whatever you need, compose it over original plate possible with holdout masks).

I am also very interested in this topic. Can someone explain the camera tracker part (importance etc….) I have read about it but still dont completely understand it's purpose.

Regards,

Wayne

The purpose of a camera track is to match a CG camera to the movement of a live-action camera, such that any added CG elements can share the movement, lensing, and motionblur of the live action.

Depending on the complexity of the move, this can be a dead-simple operation, and an extremely tedious, hair pulling, teeth clenching operation.

Though it is possible to hand-match the cameras, often 3d party applications are used. Pftrack, 3d Equalizer, and Boujou are a few of the most notable.

keyframe
Though it is possible to hand-match the cameras, often 3d party applications are used. Pftrack, 3d Equalizer, and Boujou are a few of the most notable.

And expensive ones too, they are…

@Wavne:
Try vodoo tracker, just to get a feeling what tracking/match moving is… its free, or try to dig icarus out somewhere. It is the grandfather of PFTrack AFAIK. It was once publicly available, but then with the upcoming of PFTrack, was withdrawn. But the net never forgets

@SYmek:
I thought it was also a standalone customer story, sometimes, but I am getting old… thanks for pointing me at the reel !

Thanks Guys….