I want to know whether earning through 3D work is halal or haram in Islam;
Which areas of the 3D industry are considered halal?
If I create game assets or low-poly environments and sell them on 3D marketplaces, is that income permissible?
Can I create environments for games or cartoons?
Is product animation halal, especially since many animations include music?
Does the use of music affect the permissibly of the income?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

The basic ruling is that design work is permissible, whether two-dimensional or three-dimensional, and earning income from it is ḥalāl. It is also permissible to create environments for games and animations, so long as the purpose of the design is something permissible – such as displaying permissible products or permissible games – even if these include figures such as cartoon images, which are not considered complete depictions of living beings.

However, it is not permissible to add music to any of these designs, and whatever portion of the earnings is in exchange for the music is not lawful.

As for the case where you yourself do not add the music, but those who purchase these designs go on to add music to them – you bear no responsibility in that regard, and the sin of doing so falls upon whoever adds it.

Allah Knows best.