zBrush user with questions on 3DC partial subdivision

[Wallan]

Hi.

 

I'm evaluating 3DC and the possibility for it to cover some things that I'm unhappy with in zBrush.

 

The main problem I have with zBrush at the moment is that it can't handle models with multiple textures without workarounds. At the moment my fix is to join all textures into one texture. It's limiting and takes time.

 

My first need, the ability to open a model with several textures and seamlessly paint them seems to work fine in 3DC.

 

My other need, the possibility do a partial subdivide is more of a problem for me. So far I have not been able to figure out how / if I can import a model, do a partial subdivide(with retained UV mapping) and export it again.

 

When I imported the model for texture painting I have the Paint, Tweek, Retopo,UV,Sculpt and Render modes. In all modes but Sculpt the models is visible but wen i go to Sculpt the model is not visible. I have also tried to import the model inte surface sculpting bet get an self intersection message  when I do so. It says I can open it anyway but nothing seems to happen.

 

I also tried Tweak mode. It seems to be possible to do all the tweaking I normally need except for partial subdivision.

 

So, am I missing something, is there a way to do what I need?

[ajz3d]

Hi Wallan.

First of all, what exactly do you have in mind when you mention partial subdivision? Subdivision of selected objects? Local subdivision? Or something else?

 

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In 3D-Coat you can import geometry for editing in three different areas of the program.

 

The first area is the sculpt room. If geometry is imported there, 3D-Coat drops all of the geo UVs and immediately triangulates it. Geometry from the sculpt room can be accessed in the sculpt room, paint room (for vertex painting) and render room. If the imported object was linked to some texture (e.g. to .mtl file) it will be imported along it and applied as vertex colours (although it's been a lil' bit broken for some time now and a workaround is required to import texture). You can subdivide the geometry before importing, but because UVs will be lost, it's probably not what you're looking for.

 

Second area is the retopo room. When you import geometry there, it will be accessible only in the retopo room and the paint room (if you enable Show Retopo Mesh). Geometry imported to retopo room will retain its UVs, but textures aren't available. You can subdivide the retopo mesh, but only with simple subdivision - Catmull-Clark's algorithm is not available. CC subdivision of all retopo groups (at once) can be done with most of the bake commands (usually it's one of the bake for per-pixel painting ones).

 

Then there's the paint room and UV room. If you choose to import geometry to either one of these rooms, it will be accessible from paint, UV, tweak and render rooms. The model will retain UV information and can be subdivided on import (with CC). You cannot subdivide selected objects though - only everything at once. If you decide to subdivide the object, then you can access the low-poly version with the View->Low-Poly command (useful for tweaking).

[Wallan]

Well I migh wanna do something like getting a figure model in and increase subdivision on the hand only for sculpting more details.

 

In zBrush I can do partial subdivision to increase polygons and After finishing sculpt I can use Decimation Master to reduce polygons. Both can be done while retaining UV:s. After that process i have more detail where needed but a model with same or even less polygons in total.

 

It works fine. Only problem is that when exporting i will only get one material so I either must pack all textures into one texture or manually split model to one Tool per texture. Both workarounds take time.

 

I really like the painting, retopo(almost never need that), and UV in 3DC.

Tweek does most things i would need.

 

It's only that little last thing that don't seem to work the way I need I guess.

Pity, would be a "Must have application" if it I could subdivide and reduce polygons in selected areas with retained UV:s in the tweek room as well. 

 

As it is, I suppose subdividing on import to paint room is the closest I get.

I tried it and expected to get a choice of levels of subdivision but there is only no subdivision or a single number of 4 milions something. Cant I select how much subdivision I want, a lot of things got terribly slow?

 

So lets say that I could add the level of details I want this way.

Is there something in 3DC corresponding to the Decimation Master in zBrush that can take the model down from say 4M polygons to 200k-400k  with retained visual quality and retained UV:s?

 

 

 

I'm currently running as demo, when trying to change texture size i cant select 4096 and larger. They are marked as diasbled.

Is this because I'm running a demo or is there another reason for them being disabled.

I need to know becase my single texture models uses 8k textures?

[ajz3d]

Well I migh wanna do something like getting a figure model in and increase subdivision on the hand only for sculpting more details.

In zBrush I can do partial subdivision to increase polygons and After finishing sculpt I can use Decimation Master to reduce polygons. Both can be done while retaining UV:s. After that process i have more detail where needed but a model with same or even less polygons in total.

Well you cannot retain UVs when you import a model into Sculpt room. You have however several ways of increasing local density of your sculpture:

- using Subdivide tool

- using SHIFT or CTRL+SHIFT action of any of the surface tools.

In both cases your VoxTree layer must be in surface mode (the letter to the left of its name must be an "S", not "V").

 

It works fine. Only problem is that when exporting i will only get one material so I either must pack all textures into one texture or manually split model to one Tool per texture. Both workarounds take time.

I really like the painting, retopo(almost never need that), and UV in 3DC.

Tweek does most things i would need.

It's only that little last thing that don't seem to work the way I need I guess.

Pity, would be a "Must have application" if it I could subdivide and reduce polygons in selected areas with retained UV:s in the tweek room as well.

As it is, I suppose subdividing on import to paint room is the closest I get.

I tried it and expected to get a choice of levels of subdivision but there is only no subdivision or a single number of 4 milions something. Cant I select how much subdivision I want, a lot of things got terribly slow?

You get only one subdivision level because paint, tweak and UV rooms are supposed to be used on low-poly geometry. The heavier your asset is poly-wise, the less subdivision levels you will be offered to choose from. I don't know why it has been implemented like this, but there seems to be some kind of poly cap here. Normally, for low-poly meshes you can have up to 6 subdivision levels, which is more than enough for texturing.

 

So lets say that I could add the level of details I want this way.

Is there something in 3DC corresponding to the Decimation Master in zBrush that can take the model down from say 4M polygons to 200k-400k with retained visual quality and retained UV:s?

Only without retaining UVs. If your sculpt is in surface mode, then you'll find it in Sculpt->Decimate - this will decimate the whole layer. For local decimation you can set SHIFT or CTRL+SHIFT action of a surface brush to Decimate, or you can use Clean Clay tool set to Decimate.

 

I'm currently running as demo, when trying to change texture size i cant select 4096 and larger. They are marked as diasbled.

Is this because I'm running a demo or is there another reason for them being disabled.

I need to know becase my single texture models uses 8k textures?

Probably because of the demo. 3D-Coat supports textures up to 16384 square pixels though I recommend using UDIM and smaller maps instead of single 8k+ ones. Less wasted texels and it feels faster. Edited September 16, 2015 by ajz3d

[Wallan]

Thank's for helping.

 

Suppose 3DC won't be the big savior for me.

 

A pity, being so close.

 

As it is I will still have to use zBrush for partial subD and mesh decimation, witch means that I still must keep my single 8k textures.

If I could have done it all in 3DC  I would not have any need for that 8k textures,

 

Well well.

 

Lack of partiall subdivision the way I need it to work can to some extent probably be replaced with the ability to paint normals directly to textures rather than trough real geometry.

 

Will have to test those possibilities a little more.

[ajz3d]

How about the following workflow?:

1. Import your sculpture into Sculpt Room (Without voxelization).

2. Sculpt local hires details (LiveClay toolset dynamically adds more resolution to painted areas while you brush). You can also use tools that I described above to manually increase local resolution. Decimate a bit if you notice performance drop.

3. Import your low-res mesh to Retopo Room (it will keep its UVs).

4. Create several UV-sets that will act as UDIM and distribute selected UV islands among them.

5. Bake normal and/or displacement maps (use subdivision if necessary).

6. Texture-in even more details in the Paint Room.

7. Export the model and textures with Export UV-Sets as Tiles option enabled.

Edited September 17, 2015 by ajz3d

[Wallan]

I will give it a try.

 

But when importing for surface sculpting (had no luck before but with voxelisation turned of it worked) the mesh loads with a lot of "random" polygons beeing semi transparent. How do I solve this?

[ajz3d]

I'm not sure what these semi-transparent polygons might be. Maybe inverted normals? Can you post a screenshot depicting this phenomenon and your import settings?

Edited September 17, 2015 by ajz3d

[TimmyZDesign]

I think maybe that is just because you need to switch to another tool. You are seeing the preview and the actual mesh at the same time, so there is flickering of polygons occupying the same space until you exit the merge tool. Just a suggestion, maybe it will help...

[Wallan]

Tried to reload the model again and this time it worked better.

However, the model imported is tiny and I cant zoom in close enough.

Found a preferences/view/Near Plane Modulator that I tried to change setting for but it made no difference.

Any other setting that could fix it? 

 

Guess scaling up would solve it but want to avoid it if possible.

[ajz3d]

Tried to reload the model again and this time it worked better.

However, the model imported is tiny and I cant zoom in close enough.

Found a preferences/view/Near Plane Modulator that I tried to change setting for but it made no difference.

Any other setting that could fix it? 

 

Guess scaling up would solve it but want to avoid it if possible.

Experiment with those three settings:

Geometry->Define Measurement Units->Units

Geometry->Define Measurement Units->UnitsScale

Geometry->Edit Scene Scale->SceneScale.

They will affect scale of the 3D-Coat scene only (your model should still export in original scale) and modify settings of various tools to fit this new scale.

 

I usually work with: (Meters, 1000, 100) [units, UnitsScale, SceneScale].

 

Near Plane Modulator never worked for me.

[Wallan]

Ok. Better:)

 

All brushes are incredibly large is there any overall size adjustment option for the brushes that scale them all down closer to whats useful for my model?

 

Also, when I try to sculpt on my model, that's made of several parts, such as torso and arms.

It seems as I only can scultp on one part at once, witch destroys the model when working on borders between parts.

 

Is there any option that makes it possible to work on all parts at the same time?

Edited September 18, 2015 by Wallan

[ajz3d]

Is it their visual representation in the screen space that is large or their numerical radius (order of magnitude)?

--

Some of the brushes, like Move and Pose have Through All Volumes checkbox available. By ticking this option you enable them to affect all visible and non-ghosted VoxTree layers that are caught within the brush radius.

 

Most of the brushes don't have this option I'm afraid. But it sounds like a good feature request.

Edited September 18, 2015 by ajz3d