Texture Sources

Here is a list of sites where you can download some decent textures.
Note that most textures available these days are procedurally generated and made for PBR materials. TDM uses a non-PBR engine (idtech4), so these textures typically require some work to make them look good in game. See Textures for more information.

Free

• Textures.one - search engine for multiple free texture sites.
• Texture Haven – 1k to 8k textures, no signup required.
• CC0 Textures – 2k to 8k textures and Substance files, no registration required.
• Share Textures - seamless, CC0, no registration required.
• cgbookcase.com - CC0, PBR, no registration required.
• 3DTextures.me - CC0, no registration required. Free for basic downloads (Patreon supporters may get higher resolutions + source files).
• OpenGameArt textures category - No registration required. CC and/or GPL licences. Lets you search by licence.
• HDRI Haven - photographic panoramas for skyboxes, etc. CC0, no registration required. You'll need to convert them to cubemaps.
• A collection of royalty-free particle shapes from the makers of the TimelineFX software.

Other sources

• Poliigon – Textures, brushes, models, and HDRI maps, usually for architectural rendering. Only some of those are free. Textures from 1k to 8k. Requires login credentials.
• Quixel Megascans – Textures and models, selected free assets. Signup required.

Please add to this list.