EXR animated Metadata

[alainfx]

Hi,

In this field :
Render Settings-->VRay Common-->Image File Output-->Image format options-->OpenEXR options-->Extra Attributes
we can easily add something like this : int_attr=53;float_attr=3.14;vec3_attr=(1, 2, 3)

Is it possible to have it animated ?
For example we would have some transform or shape node that has an attribute called "oilPrice", and animated it with maya.
Then we would add this in the OpenEXR options-->Extra Attributes : float_anim=<oilPrice>

So in Nuke we could get that animated oilPrice animated value.

Cheers.

[bigbossfr]

Hi,
Why you do not use preRender/preFrame mel ?
Like :

string $x = `getAttr "myshape.translateX"`;
setAttr "vraySettings.imgOpt_exr_attributes".....

[alainfx]

Hi,
I haven't tried it yet, but is it supposed to work with Settings ?
(maybe VRay only reads this setting once, at the start)

There are already several variables that are animated elsewhere, for example you can animate a VRayUserColor attribute and read it using the VRayUserColor node.
Some mel script in preFrame would also have made it possible, but this attribute solution was added, to make it easier to use.

[bigbossfr]

I haven't tried, but i don't see why it will not work.
You can also use expression, but not tested.
Expression is more simple.

[vlado]

I'm not sure it will work if you change it from a pre-frame MEL, I have to check.

Best regards,
Vlado

[alainfx]

I'm not sure it will work if you change it from a pre-frame MEL, I have to check.

Thanks Vlado.

I haven't tried, but i don't see why it will not work.

It depends on how VRay reads this part of the settings before rendering :
-Only once before render --> an expression or preFrame mel would not work.
-Before each frame --> it would work.
So if it didn't work it would not be a bug, it would just be one of the 2 possible ways.

You can also use expression, but not tested.
Expression is more simple.

It's more a pipeline matter for me.
I already have lots of expressions, scriptJobs, scriptNodes, etc...
This is all "active" stuff, and at some point it could create side effects if I forget one of them.
So, having something that is "passive" from my side would be nice.
But this is not a show stopper, I can live without it

[ivaylo.ivanov]

You are right, currently it is exported at the start of the sequence only. We must think what is the best way to implement it.

[alainfx]

You are right, currently it is exported at the start of the sequence only. We must think what is the best way to implement it.

Thank you.

[ivaylo.ivanov]

Implemented after revision 22424. When you put something between <> brackets, the expression first is tested for an attribute name. If the test fails, it's executed as a generic mel script. If this fails also, it's executed as a python script. These tests are done every frame, and they will try to catch changes in the returned values whatever the expression is.

[alainfx]

Thank you !
Is it in the "stable" nightly, or in the "nightly" nightly ?

[vlado]

Nightlies only; it's not tested well enough to make it into the stable builds.

Best regards,
Vlado

[alainfx]

Thank you.