Instant-ngp: https://github.com/NVlabs/instant-ngp
Although Nvidia's instant-ngp isn't directly suited to building 3D models, it can output them.
This code allows the capabilities of it can be tested without any local installs or local GPUs: https://colab.research.google.com/drive/1mi3HuK4vBvmY6cc2nU6jgfjN8GpuA2ls?usp=sharing
Instructions are included for how to make your own scenes, which requires a local install of colmap, but no GPUs.