HDRP MTree is not baking billboards properly. I can't imagine how others have not noticed this, except perhaps because they are baking the billboards close to the lighting conditions they have... for the scene they baked in.... or perhaps because billbaords are not seen much intheir games, but in a top down game they dominate, and with a bright spot in the middle... of every tree when seeing hundreds at once ...its very noticable. Notice also how the left ones are brighter than the right ones. When rotated, this also causes weirdness in the way the forest looks, and causes color problems as well. Those roots really tie the tree together. Look awesome. EDIT: After lots of experimenting and changing of the billboard camera, (including putting in my own local volume and directional light rotated to face down on top of the tree instead of from the side) I finally got satisfactory billboards. EDIT II: I ended up not needing billboards of any real detail. Instead I modeled out low poly tree models, and the amount of savings in Tris, combined with the GPUInstancer Asset store asset, made it so I could have a map full of thousands of tree models, about 800 tris each, at about the cost of only 20 fps at most.