sculpting crash issue

[Dateline NBC]

85% of the time i go from sculpt mode to object mode with tab it instantly crashes with not even a millisecond of freezing, just closes.

[Scre]

there are loads of things that can cause this, we need more details like PC/Mac specs, how many verts we talking about, how complex is the sculpt ?

[Mr Chappy]

Are you sure that when you press Tab it is returning you to Object mode and not to Edit mode, I normally find it takes me to Edit mode.
Edit mode can struggle a lot with a high poly sculpt and could easily crash your system. Use the drop down menu instead to make sure you are going to Object mode and see if you still have the problem.

[Dateline NBC]

Originally posted by Scre:

there are loads of things that can cause this, we need more details like PC/Mac specs, how many verts we talking about, how complex is the sculpt ?

gtx 760 2gb
i5 4670 3.4 ghz
8 gb ram

the complexity doesn't make me lag one bit (using multiresolution subdivision for it) and i can click subdivide upto like 6 times without it getting laggy, even subdividing it to stage 3 can get me a crash.

Originally posted by Mr Chappy:

Are you sure that when you press Tab it is returning you to Object mode and not to Edit mode, I normally find it takes me to Edit mode.
Edit mode can struggle a lot with a high poly sculpt and could easily crash your system. Use the drop down menu instead to make sure you are going to Object mode and see if you still have the problem.

and actually it's not what you think it is, i ESPECIALLY MAKE SURE that i dont return to object mode after sculpt so that it doesn't crash, so i always try to make sure it stays on edit mode before going back into object mode

[Mr Chappy]

I tend not to use Multires unless I have to, my system for some reason seems to run smoother when I use other options. Dynotop is my preferred choice which may not suit you... I only use Multires for the last level of detail so I can turn it off when I'm not sculpting.

Just noticed something odd when using Multires, when I switch from sculpt to edit to object mode and keep repeating this switching loop my RAM usage goes up each time I complete the loop, getting bigger and bigger and bigger, some sort of memory leak... This could cause you a problem so def check on what your RAM usage is.

[Mr Chappy]

If I just loop from Sculpt mode to Object Mode without going into Edit mode then this memory leak is almost completely gone.
Try cutting out going into Edit mode from your workflow, set the Mutlires preview setting to something a lot lower than it's sculpt setting so when your return to object mode it hopefully won't be a problem.

(I did check the mem leak with just looping between Sculpt and Edit modes(no Object mode) and the problem does exist with this workflow).

I'm out of ideas if this does not sort out your issue...

[Mr Chappy]

I don't think its an actual memory leak. I think it might be the RAM needed for "undo", mine levelled out after a lot of looping at 3300 MB but that is a HUGE increase from the 97 MB I started out at.

Like I said above cutting Edit Mode out of the loop pretty much stops this from happening, which makes sense now I think I know the cause. You could also look at the setting for "undo" as another option.

[Dateline NBC]

Originally posted by Mr Chappy:

I don't think its an actual memory leak. I think it might be the RAM needed for "undo", mine levelled out after a lot of looping at 3300 MB but that is a HUGE increase from the 97 MB I started out at.

Like I said above cutting Edit Mode out of the loop pretty much stops this from happening, which makes sense now I think I know the cause. You could also look at the setting for "undo" as another option.

thanks for the advice
butafter actually playing with and discovering dynotop i think im gonna stick with that, its pretty swell.

[Mr Chappy]

Yep I'm a big fan of Dynotop, though you may need to learn how to "Retop" as a result. It's not that hard but it can be time consuming...

[Dateline NBC]

Originally posted by Mr Chappy:

Yep I'm a big fan of Dynotop, though you may need to learn how to "Retop" as a result. It's not that hard but it can be time consuming...

retop?

[Mr Chappy]

Dynotop sculpted meshes generally have very bad topology(look this up if you have never heard of it). As a result they can be hard to UV unwrap and therefore to texture. They are also no use for animation in this state, animation works well with quads but not with tris.

To fix this issue you retop a dyno sculpted mesh to give it good topology so you can unwrap/bake(generating a normal map etc from your high poly dynotop mesh for your lower poly retopped mesh)/animate etc.

There are plenty of youtube videos showing how to retop in Blender :

Quick timelapse overview : https://www.youtube.com/watch?v=eP9WQpt4Ahk
Great full tutorial from start to finish : https://www.youtube.com/watch?v=pO58JyGh7SM

Multires avoids this issue but has it's own drawbacks, like using way more polys in places where they are simply not needed which eats up your systems power, and not being as fluid when sculpting.

[Dateline NBC]

Originally posted by Mr Chappy:

Dynotop sculpted meshes generally have very bad topology(look this up if you have never heard of it). As a result they can be hard to UV unwrap and therefore to texture. They are also no use for animation in this state, animation works well with quads but not with tris.

To fix this issue you retop a dyno sculpted mesh to give it good topology so you can unwrap/bake(generating a normal map etc from your high poly dynotop mesh for your lower poly retopped mesh)/animate etc.

There are plenty of youtube videos showing how to retop in Blender :

Quick timelapse overview : https://www.youtube.com/watch?v=eP9WQpt4Ahk
Great full tutorial from start to finish : https://www.youtube.com/watch?v=pO58JyGh7SM

Multires avoids this issue but has it's own drawbacks, like using way more polys in places where they are simply not needed which eats up your systems power, and not being as fluid when sculpting.

so he overmodelled the sculpture with an actual modelling layer? huh

[Mr Chappy]

Yep, you use the "Snap to" feature enabled when working on a separate mesh which projects the verts onto the high poly mesh.