You can texture a high poly 3D model without manual retopology by using auto-retopology tools to create a low poly version, baking high poly details (like normal/ambient occlusion maps) onto it, or using software with automatic UV unwrapping for direct high poly texturing.
- **Auto-retopology + baking**: Tools like ZBrush’s ZRemesher or Blender’s Decimate Modifier generate clean low poly meshes quickly. Baking transfers surface details so the low poly appears high resolution when textured. - **Direct high poly texturing**: Software like Substance Painter or Mari uses auto-UV unwrapping for simple models, letting you texture the high poly directly.
For beginners, start with ZRemesher for auto-retopology then bake maps in Substance Painter—this workflow balances detail preservation and ease of use without manual retopology.