Post Parent World Transform Information

[marcoF]

Hello Houdini Folks,

I am working on a Outer Space Scene where i have the Earth and the Sun. The Suns orbit around the Earth is controlled via the Sun beeing parented to a Null in the Center of the Earth.

So far so good, but now i have no clue how to get the World Space Transformation Info from the Sun AFTER i have rotated the Null. The Problem is that the Transform of the Sunlight stays the same (i guess local).

I need the Suns Position to control a tool that generates a gradient over the earth dependend from the suns position - Tool works perfect but now after Parent-Rotation doesnt fetch the correct Transform Data.

Help would be very much appreciated cause im going nuts with such a basic thing since some hours

 

Cheers, Marco

 

[marcoF]

Here is a hip file if i didnt make myselfe quite clear. The Gradient that is dependent on the Sun position is inside the Cloud Geo.

Im using Mops and qlib if somebody gets broken assetmessage.

 

 

earthTransformGradient.hiplc

Edited May 7, 2019 by marcoF

[marcoF]

I found the solution by accident if somebody is interested.
if you click on a parameter with the right mouse you can choose "reference-scene Data". And from there you can pick any object in your scene, local transform or world transform. 
So the solution was build in. I am still curious how to do that manually but for now it works like this.