[Ruby API] Instancer scaling up during animation

[jiminy-billy-bob]

In Skatter, we use an Instancer V-Ray plugin to export "Render only" Skatter setups to V-Ray.

It works fine, except in animations. Instances duplicated via an Instancer plugin double in size at each new frame.
Our code is not called after the initial on_model_exported event, so I'm guessing this is an issue in V-Ray itself.

How to reproduce:
- Create a Skatter setup, pick a Host and a Scattered Object, and enable "Render Only"
- Create two SketchUp scenes
- Enable Animation in V-Ray
- Render

I attached an example .skp showacsing the issue. You need to have Skatter v1 installed, and simply start a render.

[jiminy-billy-bob]

Can someone at Chaos please tell me if you have registered this issue in your internal bug tracking system?

[Peter.Chaushev]

Hello, Thomas,
Apologies for the late reply!
The issue is logged in our internal tracking system (priority set to 'high').
A solution is pending. We will keep you updated on its progress.

Kind regards,
Peter

[jiminy-billy-bob]

Great, thanks!

[konstantin_chaos]

Hi jiminy-billy-bob ,

The animation issue that you're experiencing can actually be resolved completely on your side.
I assume that the instances property of the Instancer plugin is exported with the following data in your case:

Instancer InstancerName {
instances=List(
0,
List(1, TransformHex("D8B..."), Transform(Matrix(Vector(1, 0, 0), Vector(0, 1, 0), Vector(0, 0, 1)), Vector(0, 0, 0)), SU|44|29827),
List(2, TransformHex("5DB..."), Transform(Matrix(Vector(1, 0, 0), Vector(0, 1, 0), Vector(0, 0, 1)), Vector(0, 0, 0)), SU|44|29827),
List(3, TransformHex("130..."), Transform(Matrix(Vector(1, 0, 0), Vector(0, 1, 0), Vector(0, 0, 1)), Vector(0, 0, 0)), SU|44|29827),
List(4, TransformHex("5BB..."), Transform(Matrix(Vector(1, 0, 0), Vector(0, 1, 0), Vector(0, 0, 1)), Vector(0, 0, 0)), SU|44|29827)
);
}

The second transform for each of the items is its velocity transform and for static instances should be using a zero matrix instead of an identity one.

The correct way to set the velocity transform:
Instancer InstancerName {
instances=List(
0,
List(1, TransformHex("D8B..."), Transform(Matrix(Vector(0, 0, 0), Vector(0, 0, 0), Vector(0, 0, 0)), Vector(0, 0, 0)), SU|44|29827),
List(2, TransformHex("5DB..."), Transform(Matrix(Vector(0, 0, 0), Vector(0, 0, 0), Vector(0, 0, 0)), Vector(0, 0, 0)), SU|44|29827),
List(3, TransformHex("130..."), Transform(Matrix(Vector(0, 0, 0), Vector(0, 0, 0), Vector(0, 0, 0)), Vector(0, 0, 0)), SU|44|29827),
List(4, TransformHex("5BB..."), Transform(Matrix(Vector(0, 0, 0), Vector(0, 0, 0), Vector(0, 0, 0)), Vector(0, 0, 0)), SU|44|29827)
);
}

This should resolve the animation issue.

Regards,
Konstantin

[dominic_baker]

Hi Konstantin,

I am still experiencing the issue. I cannot find the velocity Transform menu in my Vray window. The only plugin I am using is Skatter before beginning my render, I am using Sketch up 2019

Dom

[jiminy-billy-bob]

This should resolve the animation issue.

Indeed it does!
I never thought an identity matrix would transform the instances, but I guess it can make sense depending on the implementation.

Thanks a lot, this is resolved!

[akylbek_orozaliev]

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[jiminy-billy-bob]

Does this happen to you using the latest version of Skatter?

[akylbek_orozaliev]

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