It’s not like the emissive output of the material is like a brush like you know from photoshop. Your adjusted material for example acts like a global stencil now, it’s not like like you press anywhere on the texture and you get your square shape. To make this work like a normal brush you need way more than just multiplying by a texture and it’s not only “adjust the texture”, because this is way more tricky. The material is not as easy as you think and your explanation are just reading from nodes. You don’t say anything why we need the vector length or why we are subtracting this length by 1. All you state are the obvious adjustable parameters. In the stream it feels like you wanted to explain why we are using this math, but hesitated and just said what it does and skipped all the math logic. If you reply with “I’m not here to teach you math” then you miss the point of teaching people how things work. In the end, I want to see you doing this material from scratch without looking at the solution. And no this is not specific for my needs, it’s just a plain simple brush we all know from any other paint application. If you can do this, I’ll take everything back <3.