(Fixed, Fixed, Fixed) [HOU-1685] [HOU-1616] [HOU-1549] motion blur issues

[LeoYfver]

when rendering velocity blur it doesnt take the interval_center/shutter_offset into account. mantra does this correctly.

It also seems too take into account the geomtry before and after which i think shouldnt be the case. maybe im worng here though.


I have examples in this scene:

https://drive.google.com/file/d/1S2U...ew?usp=sharing

vray version: 43001, 87bfc3a
houdini 17.5.327 linux

[Gosho.Genchev]

Hello!

Messaging to inform you we're looking into this. In short, when velocity blur is used, we write the velocity channel itself with the mesh so those options on the ROP have no effect, by design.
We'll see if we can do something about this and come back to you with more info.

All the best!

[LeoYfver]

Thanks for looking into it! As of now i cant match the velocity without changing the interval_center on the node which in this case i dont want

Regards Alexis

[LeoYfver]

Gosho.Genchev Was wandering if there is some progress here. We always have had trouble matching fx elements with velocity blur with our deformation/transformation blur and we are using weird values in our motion blur settings to get them to match somehow. I think this is the problem that causes it.

[bdancer]

Next nightly will contain some fixes, let me know pls if those will work for you.

[LeoYfver]

it works! and it helps alot having this fixed.

In the example scene there is also an example of sphere that is both transformed and has velocity blur. We just want to take into account the @v attribute when we have it and not both @v and geo samples. Is there a way to do it?

it is the example to the right with the trail1 node

[LeoYfver]

here is a bit more visible problem. When having an alembic with frame range like alembic_1000.abc, alembic_1001.abc, alembic_1002.abc and i have duration on 0.5 and interval center it will try to find a geometry that dont exist. In this case we dont want that, we just want vray to pick up the velocity from the @v attribute

https://drive.google.com/drive/folde...-R?usp=sharing

[LeoYfver]

This is starting to beome a bigger problem now when we mix different kind of geometry in the scene. Is it something that can be looked at?

in this example scene there is 2 alembics that should have the same motion blur. But because 1 has a framenumber in its sequence it picks it up from the wrong frame.

https://drive.google.com/drive/folde...Qa?usp=sharing

Regards Alexis

[bdancer]

Changes are currently under review, both cases will be fixed next week.

[LeoYfver]

sounds good, thanks

[LeoYfver]

Everything works perfect in latest nightly. Thanks alot for the fixes!

[LeoYfver]

geometry blur dont work in version "43001", "657d636" no moblur at all. Works in version "43001", "490e262".

[LeoYfver]

We also have wrong behaviour with motionblur when instancing. Here is an example file explaining the issue

[Gosho.Genchev]

geometry blur dont work in version "43001", "657d636" no moblur at all. Works in version "43001", "490e262".

It was indeed broken but should work in 657d636 - it does for me, and our tests go through successfully there.

[LeoYfver]

Gosho.Genchev did you guys get time to check the instancing motion blur issue above?