ZBrushCentral

Lag / delay while sculpting using Dynamic Subdivs

ZBrush Usage Questions
#1

Hi all,

I hope someone could shed some light on this issue…

If I have Dynamic Subdiv button on - my brush strokes are slow even the cursor takes a while to catch up to the pens new position. (Geometry> Dynamic Subdiv> SmoothSubdiv. Set to default 2.
However if I apply the Dynamic Subdiv so they become real subdivions (3 levels) I don’t have much lagging/slowing happening, even though the Total points has gone up.

Troubleshooting:
Checked and there are no actual subdivisions while using Dynamic Subdivs.
Turning off lazy mouse had no effect.
Updated windows 10.
Tried updating XP PEN drivers.
Set Dynamic Subdiv> SmoothSubdiv. Set to 1. Which helps BUT doesn’t give a clean preview, the way I prefer to work in early on.

Specs:
Processor: i5 6600K
Ram: 16GB
GPU: GeForce RTX 2060 (set in creator mode - new driver) - also tested game mode without any luck.

HDD: more then 100GB free SSD.

Never had this issue before.

Thanks!

#2

There is a performance cost associated with sculpting on a mesh with virtual subdivision. This performance hit will be substantial if it is applied to a mesh that already has a medium or higher polycount. It’s really only intended to be a low-poly modeling aid.

If you’re looking to do sculpting–as opposed to modeling–work over multiple subD levels, then you should create those subdivision levels traditionally.

#3

Hello Spyndel,

Thanks for your reply.

My model is only in the block out phase with 50K points total. So I don’t think that is particularly high. Also this wasn’t an issue at all before Zbrush 2019? I also was using brushes link pinch and even a brush like that caused delay.

This why I’m concerned about this sudden change in Zbrush behavior.

Thanks!

#4

Dynamic subdivision has always caused performance lag. It is in fact the most common cause of people reporting mysterious performance problems because they have switched it on accidentally on a medium or high poly mesh (50k polygons is a medium poly mesh, btw). It is intended to be a visualization tool for low poly work where creating actual subdivision would be destructive. It is not intended to replace traditional subd levels for the purposes of sculpting.

Per the Documentation: “The Dynamic Subdivision system contains alternative functions to ZBrush’s Classic Subdivision Surface mode, allowing you to apply dynamic smoothing to your models without actually dividing the polygons.This feature is mainly designed to work in association with the ZModeler brush and low polygonal models.”

I’m not saying it’s impossible something has changed, and Dynamic SUBd is causing even more lag than it has previously in some situations if being employed outside of its intended use, but this has always been a thing.