Sticker with other than rectangular shape

[Roland Melkert]

I thought the non-planar TEXMAP modes were able to help with this without the sticker author having to take it into account.

Yes you can switch to e.g. spherical mode when the surface is closer to it, but whenever the intended surface is very irregular you'll (if you are a perfectionist) need to compensate the texture for it.

There are tools to automate this, especially in the game modelling world.

e.g. blender might offer solutions for this.

ps: also even with e.g. spherical mode you need to compensate your texture for it, the best known example of this being a world map.