This tutorial is using Auto1111 repo but others should be similar.
This is capable of completely transforming your screenshots from that 3d look to photo realism; you can also make it stylized. I will be using my Fallout 4 screenshots as some examples but you could also use it on some 3d renders of characters or drawn art. Use appropriate models for your desired style.
For my settings I use 60 steps, DPM++ Sampling, a resolution of 1920x1080 but you keep it to the aspect ratio of your initial image and a de-noising strength of 0.32 to 0.44. Different Samplers need lower or higher de-noising strengths. For making the prompt I start with deepboru tagger and adjust as needed.
Use appropriate negative embeddings/tags to fix bad iris or other issues. I hope this helps you make some cool images, thanks for reading.
