Apologies for the confusion here. Over the years the devs have shifted the Detail size values. If my memory is correct, the values in this course ranged from 10-30 px. However in recent years that same behavior is more in the 5-12 px range.
So I recommend trying:
See if that behavior better fits what's happening in the videos.
acribit and @theluthier I tried versions from 2.66 up to 3.2 and there doesn't seem to be any difference in detail size (which makes sense, because this is measured in pixels).
What does make a difference (again, because it is measured in pixels!) is the size of your window and resolution (basically the size of your pixels)
Here I made the same stroke with the same brush and settings, but the top one was made with Blender in fullscreen and the lower one with blender in a small window:
spikeyxxx Oh my...you're a mega blender detective! Maybe THAT's what the change was all along.
I remember getting several questions like this years ago and troubleshooting into the detail size having been altered...but you're right, it is based on pixels. However bizarre that the pixel size changes depending on the app window. Admittedly I don't understand that 🤔
However bizarre that the pixel size changes depending on the app window. Admittedly I don't understand that 🤔
Well when your Blender window is half the size of fullscreen (I mean half length and half width, so effectively a quarter of the size), then your model (when you don't additionally zoom or so) only uses a fourth of the amount of pixels:
spikeyxxx Oh so the detail size pixel value is calculated from the Blender window size? That seems odd to me...wonder why they do it that way.
Regardless this is a great discovery 👏
@theluthier the pixel size is the pixel size of your monitor. When you have a window smaller than full screen, it has less pixels.
If you have a 4K monitor, one pixel is smaller than on a 1920x1080 monitor.
But if you only use a part of your monitor, you have less pixels (of the same size though).
Look at the Iris example above; a one pixel stroke on the small image would be broader than a one pixel stroke on the full screen image.
It's tricky to explain, but once you have your eureka moment, it becomes so evident (like many things in CG).
So if I look at the word flower, in the larger image it is 8x2 pixels, whereas in the smaller image it is 5x1, approximately.
If I had a detail size of 1, the stroke would be the size of the word in the small image, and half the size in the larger.
A similar effect as zooming in or out with constant detail selected.
To sum up,
Its different for everyone 😁
spikeyxxx I think I finally get it. I was hung up on monitor DPI and the fact that it doesn't change relative to Blender window size. BUT the crux is that detail size calculates the pixel length of polygon edges which IS RELATIVE to window size.
