Thought I'd update this thread with what I've learned. I FINALLY (!!!) figured out how to make OMSPs. First, you don't need to do this with every swatch if you are intending that only one swatch be invisible.
For the invisible swatch, follow this tutorial to add and enable "alpha blended." https://sims4studio.com/thread/1037/make-object-transparency-add-alpha?page=1
Then, and again, this is only necessary for the invisible swatch, change the shader to "phong alpha."
Lastly, use a blank png texture file for the invisible swatch.
I found that by doing things this way I am able to interact with my object when it's invisible.
HOWEVER, I did some testing just now and found that if I simply changed the shader to "phong alpha" on my invisible swatch and didn't add "alpha blended", I was able to interact with my OMSP once it was invisible. This makes me wonder if the most recent patch fixed things.
Hope this helps :smile:
