Placing one entity relative to another.

CesiumJS
1

Hi,

I am trying to place a sphere at a relative position of a point on an entity, e.g., the wing-tip of the aircraft model or the top corner of the milk truck model. Computing the model matrix of the model it might appear straightforward to apply a translation and generate a model matrix but (for what are probably good reasons) it isn’t possible to set the model matrix of an entity.

I wondered if anyone had any suggestions as to how this might otherwise be achieved? There is a thread referring to the use of # to use a reference frame relative to the reference frame of another entity but it seems to peter out in 2016 and that approach doesn’t seem to work if coded.

Many thanks,

Hugh

2

Hi Hugh,

While you can’t set the model matrix of an entity, you can get it, then use that to transform your relative position to world space.

Here’s a working example.

Thanks!

Gabby

3

Perfect, Gabby. Thank you!