I get nice results but since it’s using normals to stretch meshes it doesn’t work with flat or hard edge geometry, so I’m trying to get the advanced sample to work now. docs.nvidia.com/gameworks/index. … sample.htm
Hey, yes you can always extract the vectors information using a TOPtochop, make sure to reduce image resolution and use the next frame mode, otherwise it can be pretty slow.
Is this meant to be the vectors of pixel movement like optical flow or something else? Maybe I just don’t get it, but if I connect a more simple source to this setup to see it more clearly(a circle top for instance, moving left to right) it’s showing vectors going in almost all directions, when I would expecct it to be only the axis of movement. Am I missing something or is the shader not actually designed to show this?
Hi, keep in mind the original optical flow shader by Andrew Benson which is used here is fast but a rough approximation, compared to more sophisticated but much slower algorithm found in opencv.
It doesn’t do too well on hard edges, and you’ll get better results if you blur your circle beforehand. Even if vectors are a bit off the overall direction is correct.
Funny timing, just saw it was added to the palette, same algorithm though. (though the palette one needs its format forced to 16/32bit float or it will clamp results to positive values)
Build 2017.7180 - Jun 05, 2017
New Palette
opticalFlow added to Tools folder in Palette.
Could somebody be so kind as to provide me an example of practical usage of this technique? Its inclusion in the palette suggests that this is of value, yet my previous comments about inaccuracy have led me to pigeon-hole it as an inaccurate, purely aesthetic technique. Is this correct?
Ha depends what you mean by “practical”, I’m mostly in this business to make pretty useless things to look at and play with, this is a recent example with this optical flow technique : instagram.com/p/BVSaPBonvKN … cent.houze
Also this one uses the same optical flow technique to push the fluid around : vimeo.com/218695680