I'm releasing a free, #opensource #3d model of a patch of crabgrass! It's basically grass with runners that make it look like a crab.
https://radiance.thinkmoult.com/html/crabgrass.html
Having multiple grass species in your model repository is vital to creating realistic looking grassy fields. This grassy patch is special, because it's been defined using #radiance photometrically accurate material definitions.