Bifrost is coming IN Maya 2015!

[ivaylo.ivanov]

Probably the velocity is in seconds, not in frames. And yes, MB of fluids is very difficult since usually you have just exact frames and velocities which means linear interpolation. We are thinking how to make the motion blur work more out of the box for bifrost meshes.

[Hampan2]

Interesting! As far as I can gather, the velocity is in seconds. Is there a workaround to scale the values to frames instead?
The goal to make moblur work out of the box sounds great also, but I would really like to get this working

*edit*

Found a velocity scale vector in the meshing fold out.

[vmp]

Hey timdog can you elaborate on how you were able to shuffle the Velocity Color Set into the Motion Vector slot of the mesh? is this then rendered with motion blur turned on the render setting's or was there another step? i need to render a short shot with a bifrost alembic

Arthur

[vmp]

ok, figured it out was pretty much as you mentioned, plug the colorset.name into the motion vector color set for the mesh. it would be good to get this to work using the alembic imported as a vray proxy

Arthur

[timdog]

Heres a clarification for anybody else interested in doing this, you create a new mesh node and from the bifrost mesh(contains a velocity color per vertex channel) you plug "outmesh" to "inmesh" and "colorsetName"(not "colorSet") to "motionVectorColorSet" . Now turn on motionblur and youre good to go. As mentioned before the MB default is extremely strong so really need to dial that down, might be a better way than tweaking duration, maybe just multiply the values down or something?

[vmp]

is there a way of doing something similar with a vray proxy? instead of meshing to alembic i created a vrproxy from the bifrost geo, i can see that the the velocity and verocity color sets are on the mesh, but i cant seem to get the info from them.

i tried using a vraycolorvertex connected the setname from the color set and plugged this into the diffuse of the proxy Material, but just renders black, doing the same thing with the alembic cache i get the color info into the shader.

Any ideas as to what i would need to do to make this work or does it even work?

Arthur

[vmp]

my bad, user error i didnt have the export vertex color option on, now that i have the verext colors if i try to connect this into the motion vector color set as timdog's connection pic motion blur doesnt work for the vray proxy.

i can use the alembic file but the problem is the water sims are pretty dense and kill the viewport performance, atleast with the vray proxy it doesnt kill the view performance

arthur

[georgi.zhekov]

You can import the alembic file as vray proxy.

[vlado]

It looks like for the moment there is no way to tell the V-Ray proxy to use the Bifrost velocity. Why couldn't they have named it just "velocity" like everyone else...

Best reards,
Vlado

[vlado]

You can import the alembic file as vray proxy.

Velocity will still not work...

Best regards,
Vlado

[ivaylo.ivanov]

I think we can reuse the "Motion Vector Color Set" attribute to tell the proxy from where to get the velocity. This is the most general form so it can work with other non-standard naming conventions. Sadly the gpuCache node (which is also exported as proxy) doesn't have this option...

[Hampan2]

In the meshing section, there is a scale factor you can dial in.
I lowered it to 1/25 and got quite nice blur.
However, since the mesh doesn't interpolate between frames you will get a very linear blur.

[vmp]

it would be great if there is a way to use the Motion Vector Color Set in the vray proxy, vray proxy is much better to use with these highres meshes.

Arthur

[ivaylo.ivanov]

Yep, this is coming in the beta 2 and some of the next nightlies.

[vmp]

excellent, this why i love using Vray
Arthur