There is an issue with the intuos pro (2017 model) driver and Zbrush R8. After a short amount of use, pressure sensitivity is decreased by roughly 50% or more. You can see this by launching zbrush and drawing a mask on a sphere. Notice the intensity of the mask. Undo your mask stroke and draw another mask stroke and undo. After a short time of doing this repetitivly you will see bug. The mask stroke will eventually become lighter in intensity and the brush size of the stroke will also decrease without having manually changed any of Zbrush’s size or intensity settings.
This does not happen with an Intuos 3. So there is something odd between Zbrush and the Intuos Pro (2017) Windows 10 drivers. I’ve tried the most recent wacom drivers, the previous drivers, and a driver version from september. They all seem to have this issue.
Other applications such as photoshop or mudbox do not experience similar odd behavior with pressure sensitivity. It does not appear to be a hardware issue. It is uniqely a Zbrush odd behavior. Alt tabbing back to zBrush has no effect. The only way to fix the problem is to relaunch Zbrush but that works temporarily. The only work around I’ve found that helps deal with this problem is to change the wacom pressure sensitivity to a “softer” setting in the wacom panel to counter balance the pressure problem in Zbrush.
I contacted Wacom. They suggested, I contact you.
I’ve made a short video showing you this odd behavior. In the video you will see me draw a mask stroke until the bug kicks in and you will notice the pressure response of zbrush change immediately. https://streamable.com/dolln