Bifrost is coming IN Maya 2015 which is huge news, first major update in Maya for years..
Just curious if chaosgroup have any plans for this and if we´ll be able to efficiently render stuff done with this great tool - trillions of particles, foam, smoke, water?
Cheers
Nope you wont, because this first Bifrost iteration does not have foam itself yet 
bifrost in 2015 is more like a tech demo…
to much features missing… there is no way to render it with a third party renderer…
you have to use mental ray…
In the introductory video it looked like it is possible to save alembic caches, so rendering those would be possible 
Also it looked like they are generating vertex colours for velocity and vorticity.
We have to look at it, but I think no one has done it, yet.
Yep, I think even without converting to alembic, we will be able to get all the data from the Maya mesh Bifrost creates. The tricky part will be supporting the bitfrost material.
if anyone was up to the challenge, it’s the Chaos team. Looking forward to your magic with this.
Maybe make a custom node? so u can collect data from biFrost mesh, like foam/speed/vel info → VrayMtl, just let me know, ill be glad to test it
cheers
btw, where can i get that ver?
If you have access to the VRay 3.0 nightlies, you can get a build for Maya 2015.
Yeah got vray 2.4 nightlies to work with alembic geo in Maya 2015 but still cant figure out how to get motionblur.
In the alembic geo, there is a world velocity channel (something velocity per second huh?), is it possible to do anything with this?
Is the velocity stored as Alembic velocity or as an extra channel - if the second, what is the channel’s name?
Best regards,
Vlado
On the bifrost mesh theres is two vertex color sets named “bifrostVelocity” and “bifrostVorticity”(says in the color set editor), the latter is good for shading foam.
Both of them is exported with the alembic mesh using standard Maya 2015 alembic export options (a checkbox named “write color sets”)
I cant really rename anything here like you can in for example naiad where you have control over channel names etc.
Either way it looks like 3d velocity per vertex data and I assume its possible to convert this to something usable in either vray or nuke?
*UPDATE* Can copy the bifrostVelocity vertex color set and rename it to “v” as I remember preferred by vray , also deleted all other vertex color sets but still no mblur.
How does vray mblur work anyway? Does it have two modes, one calculating transformation out of the actual vertexes and another one reading a v channel attached to the vertexes?
V-Ray is looking for either a “v” or a “velocity” named vector3 array property in the Alembic file (for the moment it must be vector, not color). If this is not present, V-Ray will ask the Alembic library to interpolate the vertices in time. This is only possible if the number of vertices does not change.
Best regards,
Vlado
I can get some motionblur w vray if I shuffle the Velocity Color Set into the Motion Vector slot of the mesh. It seems to be somewhat correct if not perfect but its very sensitive and I have to crank down the motionblur duration to something like 0.025. In the video you can see its working pretty well but theres also some glitches in the mblur, looking down right , the first seconds, theres some weird “flashing” going on at the edges. I suppose this is because this motionblur is limited to a one frame interpolation and cant curve in its motion? Anyway its a starter: https://vimeo.com/95202751
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.
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.
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
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
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?
