another dilemma with vrayphysical camera and blur

V-Ray V-Ray for 3ds Max General
1

vrayphysical camera blur doesnt work with meta particles like water from the super spray particle emitter. :frowning:

And motion blur in the renderer tab doesnt work when using vrayphysical camera.

So… how do I get motion blur for my water particles when using vrayphysical camera?

2

more info

It seems you cant use motion blur for mesh deformations (meta particles) with a regular camera or with a vrayphysical camera.

So I guess I’ll have to try doing the motion blur (post process) in the video editing package (I currently use vegas, but hope to try final cut pro eventually).

3

in my understanding, when using physical camera, all settings in render setting (camera) are ignored and instead, the settings from physical camera are used. For example, all you need to do is check - use motion blur, and then adjust your shutter in the camera.
Meta meshes are a different story; since they have changing topology from frame to frame, i.e. number of vertices changes, there is no way to blur them inbetween frames. However, in some cases such meshes carry motion information with them, such as from real flow, in that case you can blur them with duration >= 1.

4

when using physical cam, just check the motion blur box. You might have to lower the shutter speed to actually get the blur happening

5

THANKS

Thanks jacksc02… but Morbid was right on… (check his response concerning my use of metameshes)

6

hi morbid,
i’ve happend that problem a week ago. had a realflow mesh, but havn’t reached motion blur. is there a hint for getting it?

7

You should still be able to export channels and make at least some 2.5D blur happen in post, for those meshes.
Being by design very chaotic, i doubt many will see the moblur is faked :slight_smile:

Lele

8

basicly when you are exporting meshes from RF, you need to check an option = store motion information. This will compute vector inside each of the iso files. And so, when rendering with vray you can use 3d motion blur, with duration lower then 1.0 or use motion vector such as rpf output. I have done that a number of times. However this was before physical camera was intergrated. So I dont know how or if it all it will work with that.

9

:idea: ahaaa, thanks man, i’ll give it a try.

10

Re: another dilemma with vrayphysical camera and blur

This is because the mesh obtained from the particle system has a constantly changing topology (vertex and face count) so V-Ray cannnot figure out which part of the mesh goes where. Like Morbid Angel said above, a real flow mesh can provide this information.

Best regards,
Vlado

11

i cant get the real flow motion info to be seen by vray. store motion info is set to on during mesh export. i tried setting the frame duration in vray to less than 1.0 as suggested, but no blur. the only way to get it to work is to increase geo samples, but this works whether frame duration is less than 1.0 or not. what am doing wrong?

thanks

12

What are your motion blur settings currently? (Interval center and duration for regular camera, or the respective shutter settings for the physical camera)

Best regards,
Vlado

13

Currently I am using regular max camera with interval duration set to 0 and duration set to 0.5. The changing topology warning comes up (as expected since its a real flow mesh), but i thought that the motion data included in the real flow mesh would be seen by vray and overide that. is that correct?

thanks

14

You can try to keep the interval center at 0.5, and the duration less than 1.0 and see if it works.

Best regards,
Vlado

15

wow, that worked… :smile:
i can control the mblur though the realflow plugin now.

Does that mean i dont need to play with the geometric samples now (since that way a way to force deforming toplogy to mblur) or is that still important?

thanks a lot, Vlado..

16

Geo samples probably won’t make much difference since realflow is only updating itself once per frame so it wouldn’t be able to hand vray any subframe information.

17

hey thanks.. :slight_smile:

yes i noticed they didn’t do much although subdiv still had an effect on quality of the blur. i have been reading some Glu threads on here too, any thoughts on which is better in terms of workflow with vray? i just started using RF so I’m not married to it… kind of a painful program but nice fluid sims..