vray proxy+motion blur problem

[CGEV]

Hi,

We are currently working on feature film with CG crowd+stadium, so we'll probably use Vray Proxy.

I've attached an image to illustrate the result i'm trying to get with vray proxy and MotionBlur.

It's a simple scene, with an animated spheres, from frame 1 to 3.

I have motion blur checked on my render global, with interval center set to 0 and geometry sample to 8(everything else is default value).

I try to get the same result with the vrayProxy sphere(animated) ,exported with velocity .

I have exported vrayProxy with default value,then i have tried different values but i still don't get the result i'm looking for.

I'm not very familiar with vray proxy yet,so i probably missed something here.

Is there any solution for this to work?

Thanks.

Best Regards.

[vlado]

Can you post the original aniamted scene?

Best regards,
Vlado

[CGEV]

I've attached the original scene from which i've render the previous image.

Thanks.

[Svetlozar Draganov]

What settings are you using for the proxy-export - I got identical renders (motion blur) between scene with geometry and with VrayProxy.

[CGEV]

i checked export animation and export velocity :

-velocity interval start: -0.5
-velocity interval end: 0.5

I 've tried with default value first.Then i 've tried differents values for velocity interval start and end but still don't get good result.

[bigbossfr]

Vlado : it is impossible because the geometry samples of a proxy is limited to 2 (?).
Do you know a methode to have more geometry samples in a proxy ? or a workaround please ? or unlock something ?

Edit : i see what is wrong. ChaosGroup, please correct me if i am wrong :
Chervin, when you create a proxy with a velocity (export animation/velocity interval start end), it is for "deformed geometries".
For you example, create the sphere with export animation disable.
After, do the same animation for your proxy (connect all translations curves or, create a "parent constraint" with the original sphere) and you will get the same image.

If you use miarmy : http://www.youtube.com/watch?v=8k2D79ZfHJM&hd=1
As you can see, there is a character, and the character has multiple "parts" (arms, legs, head....). Each parts is a proxy (without velocity if you haven't deformation), and each part will be "drived" (by miarmy, so, with a good motion blur).

The problem can be : if you have a complexe deformation likes a arm with a complexe mouvement like your example (with the sphere), we need more sample in the proxy. But, this is an extreme case.

[Svetlozar Draganov]

i checked export animation and export velocity :

-velocity interval start: -0.5
-velocity interval end: 0.5

I 've tried with default value first.Then i 've tried differents values for velocity interval start and end but still don't get good result.

Disable "Export Velocity" and export the geometry to VrayProxy - then the motion blur should be the same.

[CGEV]

Sorry for the late reply, i did some test on my side.

I understand the 'trick' for non-deformed objects.

Indeed, connecting my "static proxy sphere" to the animated sphere works very well,the motion blur is the same.

But,i have to deal with deformed geometries in my case.

To Deex: Thanks for the video link. But unfortunately, there is no motion blur with miArmy driving vray proxy.

Forget the "sphere" and let me start from the beginning

I have cg characters mooving, running, etc...(deformed geometries ).

I have to match motion blur with live action,interval center is to 0 because i need "the middle of the interval to be at the exact frame position".

In this case, i must enable "Export velocity" before exporting VrayProxy.

I've done few tests with deformed geometries and i've succeed in getting the same result with vray proxy but:

Since velocity interval Start/End are based on Motion blur settings (duration frame and interval center), my question is:

Do I have to set my duration frame for the shot before exporting proxies or is there a way to control "velocity interval Start/End" after export?

To deex: Otherwise, you're right I have not succeeded to increase geometry samples more than 2.

[vlado]

If you are using a recent nightly build, you can maybe try Alembic; it should work fine with multiple geometry samples.

Best regards,
Vlado

[bigbossfr]

If you are using a recent nightly build, you can maybe try Alembic; it should work fine with multiple geometry samples.

Best regards,
Vlado

But Alembic takes the same memory ?

[vlado]

But Alembic takes the same memory?

.vrmesh files handle huge objects more efficiently (like millions of triangles), but for simple stuff, I guess it is comparable to Alembic, at least on the V-Ray side; not sure if the Alembic library itself takes up extra RAM for data.

Best regards,
Vldao