Spacescape tool for skyboxes.

Spacescape is a free tool for creating space skyboxes with stars and nebulas.

You can use Spacescape to make skyboxes for your free or commercial game, no license or royalties required!

See more on the official webpage.

Create textures with Materialize.

The development team comes with this great tool named Materialize:
Materialize is a stand alone tool for creating materials for use in games from images. You can create an entire material from a single image or import the textures you have and generate the textures you need.
You can use this tool for:
What can this tool do?

• Diffuse -> Height 
• Diffuse -> Metallic
• Diffuse -> Smoothness
• Height -> Normal
• Height + Diffuse -> Normal 
• Normal -> Edge 
• Normal -> Occlusion 
• Normal + Height -> Occlusion 
• Normal -> Height 
• Seamlessly tile your textures. 
• Save and load in a variety of formats. 
• Automate many processes with clipboard commands in XML format.

You can find video tutorials created by Michael Voeller:

Free textures from texturehaven .

The team from the texturehaven website come with this info:

100% Free 
All textures are licensed as CC0 and can be downloaded instantly, giving you complete freedom. 
No paywalls, email forms or account systems.

You can help this website:

With Patreon, you can contribute to help us pay the server cost and develop new texture scans.
When a goal is achieved, something new will come.
Think unlocking 8k textures, PNG files, increasing uploads and more.
Not only can you contribute financially, but you can get directly involved in the process, helping decide what textures we shoot, and ultimately the direction this site is going. 
Spendings of donation each month is verified by public finance reports.