First of all, sorry for being silent these days, I'm very busy on an RL project, but I'm still around :p
Secondly, I've been asked a few times to make a Maitreya version of the Happy Spanker. As you may know, it is currently just two spheres, regular prims, they're not even mesh. So why am I not making a Maitreya version of them ?
It would be easy, I've already made a few tight-fitted Maitreya items, like the Proud Girls and recently the Body Harness.
But if I did that I'd be faced with this alpha-sorting issue on rigged mesh. Let me explain.
The texture I made for the Happy Spanker is an alpha-blended one, meaning that it has partial transparency. It cannot be masked or it would look dirty and weird. If I made a fitted mesh version for Maitreya, it would ideally have to go under the "Underwear" layer so that when you're spanked while wearing panties or a catsuit, your butt would redden under it and not through it. Same if you are wearing jeans (either on the "Clothing" layer as an applier, or mesh jeans), as it does not make sense to see your butt redden through them.
Problem is, as I mentioned above, the texture is alpha-blended, which means it would be hidden under any other alpha-blended texture rendered on your body or even fitted to your body, like transparent catsuits, sweat, applied panties or even stockings (since they use the same lower part of the body). And it would hide an applied tattoo that is alpha-blended as well. You know this issue well I bet, this is why you have to switch "Mask Mode" on your Maitreya HUD when you wear more than one transparent layer on your body. It's annoying, it's a rendering issue (not a bug but an optimization, so it's there for a purpose and won't be fixed by LL), and it happens only with rigged mesh, not with unrigged mesh (or sculpties or prims).
This is the reason why I don't want to make a Maitreya fitted version of the Happy Spanker just yet. Not until I find another solution. If you don't believe me, you can try the Code-5 spanker that is fitted to Maitreya, and try to use it along with a transparent catsuit. It literally makes a hole through your suit. Same with sweat.
But yeah, I too would love to make a Maitreya-fitted Happy Spanker so that it follows the curve of my body perfectly. Prims are sooo 2010. More recent is not always better though, I guess.
There is hope though, that LL will release their "texture baking on
mesh" feature one day. If they do, then it might be possible to make a fitted mesh version of the Happy Spanker that won't make your butt burn through your clothes.
Have fun !