 So you don't know how to use polygroups in ZBrush, not a problem. Under polygroups you will see all the options in the poly menu. If you mask an area, and click group mask clear mask, or control W, you'll turn that mask area into a polygroup. If no mask is selected, the entire object will be grouped instead. If you use group mask, it will do the same thing, but also reverse the mask. Group is Dynamish sub will assign a white polygroup to your model. White polygroups are used to subtract shapes during dynamish, which basically just means when you dynamish two objects together, the white polygroups will be subtracted from the main object. From masking we'll divide everything into two polygroups, masked and unmasked. By polypaint we'll polygroup based on an object's painted colors. Here you can see the hair is polypainted from brown to red. So if you press this button, it will try and find similar colors and group them together. Group change point just means that you can group the last thing that you did. Just like in masking, if you hold control and left click on the timeline, and then click this button, everything you did up to this point will be grouped. Group front just assigns everything that is facing the camera the same polygroup. Group visible turns all visible objects to the same polygroup. If you don't like the colors of your groups, you can just randomly assign new ones with the regroup visible. The group by edges will isolate the edges of your object. The higher the value, the larger the edge group. Group by normals is my personal favorite. This will group polygons by angles. So for example we have a cube, a cube has six sides. Each side is very sharp and has the same angle, so if we group by normals it will automatically polygroup based on those angles. The required degrees for those angles can be changed here. The smaller the number, the more polygroups you'll have. If you press auto group, it will create separate polygroups for each object. If you click merge similar groups, it will try to group each object based on how many points they have. It's really useful when trying to separate the details from the base body. Merge stray groups supposedly takes all the random islands that are left over and puts them all into a single group. If you want to group things based on texture maps, click UV groups. If you want to group things based on UV coordinates, pick auto group by UVs. This one is really useful if you've already UV mapped a character and you want to see what the polygroups for each UV island looks like. Once you have polygroups to navigate between them, hold control shift and left click on a group and every other group will disappear. If you hold control shift and click on it again, instead it will show you all the other groups. And if you keep holding control and shift and left click on a new group, those new groups will also disappear. If you hold control shift and drag select on empty canvas, you will invert the polygroups that are visible. And at any point, if you hold control shift and left click on empty canvas, you will unhide all the groups. So, how is this useful? Because that's all we really care about, right? Well, let's say there's a part of your mesh that you don't like and you want to delete it. Well, if you mask that area, hide the group and then under geometry, modified topology and delete hidden, that part will no longer exist. Under subtool, you can also split apart an object based on the polygroups. Or let's say there's an area that you want to extrude. Well, if it's a polygroup, you can surgically extrude only that selected area. My favorite trick, though, is if you've extracted a piece of armor from the body and you want to ridge outline the edges, as long as you have things separated into polygroups, you can add a curve around that group and easily trace it with any design you want. Last thing, let's say you're sculpting with dynamesh and you're about to retopologize, but you want clean topology organizing your model into separate groups. Well, in this case, just create your groups and under deformation, polish by groups and under zero measure, keep groups, set how many polygons you want, remesh and you're done. You have clean topology separated nicely into groups. Hope that helps and as always, I'll be having a fantastic day and I'll see you around.