I have developed this model: Huermeces_del_Cerro.html
It has two toggle buttons.
The left one, hides/shows certain object of the model.
The right one, switches the texture of main object from normal to highlighted.
I would like to change this action so that the right button switches the texture from colored to grayscale.
I have seen, in the Sketchfab “3D SETTINGS”, that this is possible by changing the texture “Format” from “RGB” to “Luminance”.
Is it possible to implement this feature with the API?
Could anyone suggest the basic lines of code required to assign either “RGB” or “Luminance” to the texture “Format” parameter?