A few questions about strictly low-poly workflow

[Mistale]

Hi,

I've been using 3D-Coat on and off since I bought it last year.

It's a wonderful product, but there are a few unsolved (for me) questions that prevents me from using it for *real* work.

I'm finding it difficult to get a grip on the preferred workflows for different tasks since there's so many ways to the same thing, and I don't have enough time to really learn all the ins and outs of every combination.

I mainly do low-poly modeling for mobile games, so that's the area I'm interested in stream-lining using 3D-Coat.

Questions about sculpting:

- What's the best way of keeping multiple 3D-Coat files in the correct scale through-out the entire pipeline?

...Should I change the voxel density (doesn't seem to be working, reverts to 1.0)?

...Or res+ A LOT to get enough resolution for the scale I'm working in?

...Or use measurements on export of retopoed mesh (I guess that's a no-no if you want to merge voxel-layers from different files to check an entire scene)?

Questions about retopo:

- Is there really no way to mark an edge as hard or apply smoothing-groups to faces inside the retopo room?

Since I do really low-poly work, a lot of the defining features of each model depends a lot on whether an edge is hard or smooth.

I've read that smoothing groups can be applied upon import of meshes, but I've found no information about smoothing of edges on a mesh created in retopo room.

Questions about paint room:

- I've read on several sites that voxel-based painting is implemented. But when I try to use it, my voxel layers turn to surface mode upon return to voxel room. Is that how it's supposed to work? When I turn the layers to voxel-mode again to adjust something on the model, all paint disappears.

If this is the intended behaviour, does that mean that painting must wait until there's no more work to be done in voxel-mode?

- I find the shading used in the paint room really strange. Especially for low-poly models. Perhaps it's just because I haven't found out how to define lighting or if it's even possible. I don't know how the shading is calculated, but for me the sides of the model turns almost black, and it's just the forward-facing faces that are somewhat evenly lit.

Low smooth shading seems to be gentler than the standard shading, but I find myself switching to flat shading almost all the time to be able to see what the object really looks like. What I would really like is to be able to use different standard shaders such as vertex-lit or pixel-lit, and define ambient and diffuse (including directional) lighting in the paint room. Possible?

- How do you paint *on* edges in a good way? If I try using any brush, it always switches between applying paint on one OR the other faces, not evenly across both connected faces.

My use-case is hand-painted textures where I might want to have a highlight running on top of some of the edges.

What I wish is that the stroke would be projected on the model using the current viewport orientation, and disregard which face the origin of the brush is currently resting on. Is there a setting for this somewhere?

- Same as above, but more regarding UV-seams. Is it possible to draw *on* the edge of a UV-island inside the UV-editor? When I try, the brush symbol disappears as soon as I get close to the seam, and if I try to paint as close as I'm allowed with a small brush, there will be a small unpainted section left at the seam.

- How does drawing using lines or curves really work? Nothing happens when I try to paint using them, but the new spline-based painting works flawlessly.

Is there something that needs to be done before using those modes in the E-panel?

- Is there a way to get a decent result with the "Calc occlusion" command? I've tried using several hundreds of ray to get good AO, but I think the results look mostly like a sports stadium with shadows from several spotlights rather than the kind of AO you get from baking in xNormal or Blender.

Questions about general workflow:

- What's the preferred way to deal with changes in the model introduced later in the pipeline, perhaps even after rigging of a character in another application?

Is it best to leave 3D-Coat out of it and deal with it in an ordinary modeling application, or is it possible to import the mesh, adjust it inside the retopo room, and then export it again without losing information from a 3rd party application?

A lot of questions... BTW I don't mean to bash 3D-Coat in any way! I'm really in love with the freedom it allows when creating, and I just want to be able to get a firm grasp on how to use it for my particular use-case.

Thank's in advance!

Anders

[popwfx]

...

What's the preferred way to deal with changes in the model introduced later in the pipeline, perhaps even after rigging of a character in another application?

Is it best to leave 3D-Coat out of it and deal with it in an ordinary modeling application, or is it possible to import the mesh, adjust it inside the retopo room, and then export it again without losing information from a 3rd party application?

...

I'm not the person to answer all of your questions, however this question you ask above here is of great importance for me. It seems by far (based on the lack of responses I get to some of my workflow questions) that the typical use case is people retopo-ing and UVing & painting models created entirely in 3DC's voxel Sculpt room. This is not what I typically do - we use lots of externally created hi-res models, but want to use 3DCoat's power for Retopo, UV & Painting (& texture baking). I'm not sure what the best practices are for this workflow, but I can tell you that I've taken (LightWave) models into and out of 3DCoat for UVing, Retopo & painting with no problem.

It appears except for one thing, that 3DCoat keeps the model intact fine in all respects (including morph and weight maps on the imported geometry). The one thing it does destroy is Lightwave Skelegons (which are essentially 2 point polys that are bone placeholders for rigging) - those get stripped if I paint and export the LWO again. This is annoying but can be worked around by saving iterations and copying the Skelegons back into the model after exporting from 3DC.

Also, just to be safe, I tend to have 3 folders for objects 1) Original - contains my externally modeled stuff, 2) Pre-3DC Prepped Models - which contain my originals that are collapsed or layered or whatever to work best before import into 3DC, and 3) 3DC Output - which is the outputted UV'ed Retopoed or Painted models exported from 3DCoat. Obviously I also save the .3b files which have the imported models embedded within them.

This way I can always go back a step and tweak something if I find something is stripped or not quite right about the model.

3DCoat is relatively friendly to imported and exported media and usually doesn't screw it up for workflow using external apps, however at least with Skelegons being stripped - that is at least one problem I hope gets fixed. I also have yet to double-check whether point order gets changed too, I suspect it does, so that might make morphing between pre-3DC-import and post-3DC-export models a problem. But at least in LightWave I've found a "ReKnitter" plugin that supposedly can re-order the points and hopefully restore morphability between different iterations if needed.

But yes - I think more tutorials on the use on non-voxel-3DC-sculpted pipelines needs to be elaborated on. Otherwise, you can do what you ask here about import & export, but be careful and save iterations in case you come across something like I did with Skelegons. (I myself can't predict parts of my workflow and occasionally need to re-UV or re-texture something late in the game and need to be able to pop into and out of 3DCoat even if rigging or whatever has begun.)

[Mistale]

@photonvfx: Thank's a lot for your thoughts on the subject! That cleared it up quite a bit. I'm more used to the world of parametric cad in my daytime job, so it's great to hear how a typical workflow may look in this type of industry.

[alvordr]

Questions about sculpting:

- What's the best way of keeping multiple 3D-Coat files in the correct scale through-out the entire pipeline?

...Should I change the voxel density (doesn't seem to be working, reverts to 1.0)?

...Or res+ A LOT to get enough resolution for the scale I'm working in?

...Or use measurements on export of retopoed mesh (I guess that's a no-no if you want to merge voxel-layers from different files to check an entire scene)?

Not sure that I understand your question, as scale vs density/resolution are very different things.

Questions about retopo:

- Is there really no way to mark an edge as hard or apply smoothing-groups to faces inside the retopo room?

Since I do really low-poly work, a lot of the defining features of each model depends a lot on whether an edge is hard or smooth.

I've read that smoothing groups can be applied upon import of meshes, but I've found no information about smoothing of edges on a mesh created in retopo room.

Hard edges during sculpting can be helped by using various brushes and brush paint types (such as square, spline, etc.). However, during Retopo, it's simply the classic case of putting 2 or more edges or edge loops closer together to form the hard edge. Making them more smooth can be a case of pulling them further apart.

Questions about paint room:

- I've read on several sites that voxel-based painting is implemented. But when I try to use it, my voxel layers turn to surface mode upon return to voxel room. Is that how it's supposed to work? When I turn the layers to voxel-mode again to adjust something on the model, all paint disappears.

If this is the intended behaviour, does that mean that painting must wait until there's no more work to be done in voxel-mode?

I'll skip this question, as I do most of my work in Voxel mode.

- I find the shading used in the paint room really strange. Especially for low-poly models. Perhaps it's just because I haven't found out how to define lighting or if it's even possible. I don't know how the shading is calculated, but for me the sides of the model turns almost black, and it's just the forward-facing faces that are somewhat evenly lit.

Low smooth shading seems to be gentler than the standard shading, but I find myself switching to flat shading almost all the time to be able to see what the object really looks like. What I would really like is to be able to use different standard shaders such as vertex-lit or pixel-lit, and define ambient and diffuse (including directional) lighting in the paint room. Possible?

At the top near the [Camera] button are other buttons that allow you to adjust the angle source, intensity and ambient lighting. Play with left clicking and dragging those back and forth to get the preferred settings. The only tip I have for the last part of this set of questions is to play with the various materials on the Voxel before you bake occlusion to the paint layer.

- How do you paint *on* edges in a good way? If I try using any brush, it always switches between applying paint on one OR the other faces, not evenly across both connected faces.

My use-case is hand-painted textures where I might want to have a highlight running on top of some of the edges.

What I wish is that the stroke would be projected on the model using the current viewport orientation, and disregard which face the origin of the brush is currently resting on. Is there a setting for this somewhere?

I haven't experienced this problem. Paint goes on fine for me. However, you might consider going to Textures > Texture UV editor in the menu at the top...this will pull up a flat image of your UV layout and you can paint on that, instead.

- Same as above, but more regarding UV-seams. Is it possible to draw *on* the edge of a UV-island inside the UV-editor? When I try, the brush symbol disappears as soon as I get close to the seam, and if I try to paint as close as I'm allowed with a small brush, there will be a small unpainted section left at the seam.

Hmm....not sure here. It may help to see an image of your UV layout and model with wireframe on. The only thing that comes to mind is if you don't have all your polys UV mapped, for some reason. They won't get painted.

- How does drawing using lines or curves really work? Nothing happens when I try to paint using them, but the new spline-based painting works flawlessly.

Is there something that needs to be done before using those modes in the E-panel?

I'll skip this one, as I don't use it.

- Is there a way to get a decent result with the "Calc occlusion" command? I've tried using several hundreds of ray to get good AO, but I think the results look mostly like a sports stadium with shadows from several spotlights rather than the kind of AO you get from baking in xNormal or Blender.

I personally never use Calc Occlusion. I simply let the Retopo Room either Merge with NM and bake the local occlusion (tweaking the setting to my liking) and check 'Weld vertices' and 'Don't snap subdivision vertices to the surface,' either Auto-mapping or using my own UV setup. I do no subdivision or smoothing. Everything else is unchecked.

Questions about general workflow:

- What's the preferred way to deal with changes in the model introduced later in the pipeline, perhaps even after rigging of a character in another application?

Is it best to leave 3D-Coat out of it and deal with it in an ordinary modeling application, or is it possible to import the mesh, adjust it inside the retopo room, and then export it again without losing information from a 3rd party application?

I would suggest doing the rework in 3DC and then rigging or simply adjusting your rig afterwards.

[Mistale]

Thank's a lot alvordr for taking your time answering my questions! My replies to your answers are in the quote below.

Questions about sculpting:

- What's the best way of keeping multiple 3D-Coat files in the correct scale through-out the entire pipeline?

...Should I change the voxel density (doesn't seem to be working, reverts to 1.0)?

...Or res+ A LOT to get enough resolution for the scale I'm working in?

...Or use measurements on export of retopoed mesh (I guess that's a no-no if you want to merge voxel-layers from different files to check an entire scene)?

Not sure that I understand your question, as scale vs density/resolution are very different things.

I figured that to be able to model in "world-scale" (for example in meters), the density would have to be changed to allow for enough voxels on models that don't occupy many units in size. I want a 1x1x1 cube to ultimately export as 1x1x1 units, and to be the correct size if I merge 2 or more files together inside the voxel-room.

Questions about retopo:

- Is there really no way to mark an edge as hard or apply smoothing-groups to faces inside the retopo room?

Since I do really low-poly work, a lot of the defining features of each model depends a lot on whether an edge is hard or smooth.

I've read that smoothing groups can be applied upon import of meshes, but I've found no information about smoothing of edges on a mesh created in retopo room.

Hard edges during sculpting can be helped by using various brushes and brush paint types (such as square, spline, etc.). However, during Retopo, it's simply the classic case of putting 2 or more edges or edge loops closer together to form the hard edge. Making them more smooth can be a case of pulling them further apart.

Ok, I see what you mean. However, when fiddling about with the latest beta just now I found the option of creating smoothing groups upon merging the retopo mesh to the scene. I don't know how I could have missed it before, but it lets me do exactly what I want.

The method you propose works fine, but since I have a very limited polygon-budget on mobile games I try to avoid creating extra loops.

Questions about paint room:

- I've read on several sites that voxel-based painting is implemented. But when I try to use it, my voxel layers turn to surface mode upon return to voxel room. Is that how it's supposed to work? When I turn the layers to voxel-mode again to adjust something on the model, all paint disappears.

If this is the intended behaviour, does that mean that painting must wait until there's no more work to be done in voxel-mode?

I'll skip this question, as I do most of my work in Voxel mode.

- I find the shading used in the paint room really strange. Especially for low-poly models. Perhaps it's just because I haven't found out how to define lighting or if it's even possible. I don't know how the shading is calculated, but for me the sides of the model turns almost black, and it's just the forward-facing faces that are somewhat evenly lit.

Low smooth shading seems to be gentler than the standard shading, but I find myself switching to flat shading almost all the time to be able to see what the object really looks like. What I would really like is to be able to use different standard shaders such as vertex-lit or pixel-lit, and define ambient and diffuse (including directional) lighting in the paint room. Possible?

At the top near the [Camera] button are other buttons that allow you to adjust the angle source, intensity and ambient lighting. Play with left clicking and dragging those back and forth to get the preferred settings. The only tip I have for the last part of this set of questions is to play with the various materials on the Voxel before you bake occlusion to the paint layer.

Holy cr*p, how could I miss that!? That's exactly what I've been looking for. I've been searching through every meny, but missed the obvious spot to look for camera related functions... Guess I'm close to being legally blind

- How do you paint *on* edges in a good way? If I try using any brush, it always switches between applying paint on one OR the other faces, not evenly across both connected faces.

My use-case is hand-painted textures where I might want to have a highlight running on top of some of the edges.

What I wish is that the stroke would be projected on the model using the current viewport orientation, and disregard which face the origin of the brush is currently resting on. Is there a setting for this somewhere?

I haven't experienced this problem. Paint goes on fine for me. However, you might consider going to Textures > Texture UV editor in the menu at the top...this will pull up a flat image of your UV layout and you can paint on that, instead.

This only seems to happen with very sharp edges. I have no trouble painting edges in the viewport if they have somewhat of a fillet. Then the brush rolls over them smoothly and it's easy to paint on the edge itself. Painting inside the texture uv editor works, but it would be great if you could somehow paint as easily over sharp edges in the viewport as on any other surface without the brush constantly switching between faces.

- Same as above, but more regarding UV-seams. Is it possible to draw *on* the edge of a UV-island inside the UV-editor? When I try, the brush symbol disappears as soon as I get close to the seam, and if I try to paint as close as I'm allowed with a small brush, there will be a small unpainted section left at the seam.

Hmm....not sure here. It may help to see an image of your UV layout and model with wireframe on. The only thing that comes to mind is if you don't have all your polys UV mapped, for some reason. They won't get painted.

All faces are mapped. It just seems that there is some type of barrier that prevents painting exactly at the edge of the island. Imagine a uv-mapped cube where the seams are located at 90 degree edges. If I want to paint a stroke directly on the edge which is shared by two islands, I can chose between painting in the viewport and get the same problems with the brush switching between faces as in the previous question, or try to paint the stroke two times in the texture uv editor (painting exactly on the edge of each island that shares the same edge). It's the latter method that won't work since I'm not allowed to put the the brush with it's center on the island's edge.

- How does drawing using lines or curves really work? Nothing happens when I try to paint using them, but the new spline-based painting works flawlessly.

Is there something that needs to be done before using those modes in the E-panel?

I'll skip this one, as I don't use it.

- Is there a way to get a decent result with the "Calc occlusion" command? I've tried using several hundreds of ray to get good AO, but I think the results look mostly like a sports stadium with shadows from several spotlights rather than the kind of AO you get from baking in xNormal or Blender.

I personally never use Calc Occlusion. I simply let the Retopo Room either Merge with NM and bake the local occlusion (tweaking the setting to my liking) and check 'Weld vertices' and 'Don't snap subdivision vertices to the surface,' either Auto-mapping or using my own UV setup. I do no subdivision or smoothing. Everything else is unchecked.

This seams to be a user error from my side. I assumed that the calc occlusion command baked the occlusion from the voxel-model, but since the result is so different from what you get using your proposed method, I guess it only calcs it from the low-poly mesh. Any way, the AO looks fine when baked during merging. Thanks for the tip!

Questions about general workflow:

- What's the preferred way to deal with changes in the model introduced later in the pipeline, perhaps even after rigging of a character in another application?

Is it best to leave 3D-Coat out of it and deal with it in an ordinary modeling application, or is it possible to import the mesh, adjust it inside the retopo room, and then export it again without losing information from a 3rd party application?

I would suggest doing the rework in 3DC and then rigging or simply adjusting your rig afterwards.

Okay, will try that!

[alvordr]

All faces are mapped. It just seems that there is some type of barrier that prevents painting exactly at the edge of the island. Imagine a uv-mapped cube where the seams are located at 90 degree edges. If I want to paint a stroke directly on the edge which is shared by two islands, I can chose between painting in the viewport and get the same problems with the brush switching between faces as in the previous question, or try to paint the stroke two times in the texture uv editor (painting exactly on the edge of each island that shares the same edge). It's the latter method that won't work since I'm not allowed to put the the brush with it's center on the island's edge.

I would say that perhaps the UV seams need to be cut in such a way that the edges you're concerned about aren't the seam...that way they should overlap in the island, as you paint. This isn't the answer I would call THE answer, but it might help.

[Mistale]

I would say that perhaps the UV seams need to be cut in such a way that the edges you're concerned about aren't the seam...that way they should overlap in the island, as you paint. This isn't the answer I would call THE answer, but it might help.

Thanks for your effort! In this case I'm modeling sharp jagged rocks, and I see no other way than placing the seams at the edges.

[Jax_Cavalera]

Ok, I see what you mean. However, when fiddling about with the latest beta just now I found the option of creating smoothing groups upon merging the retopo mesh to the scene. I don't know how I could have missed it before, but it lets me do exactly what I want. 

The method you propose works fine, but since I have a very limited polygon-budget on mobile games I try to avoid creating extra loops.

Thank's a lot alvordr for taking your time answering my questions! My replies to your answers are in the quote below.

 

Would you by chance be able to explain briefly what you did here to use this feature please.  I'm trying to use 3D Coat for Low Poly modelling as well and baking plus small tid bits like that feature would really be great to understand.  Also.. do you experience artifact problems when you do low poly baking and how do you approach things like the toes and fingers of your models when building a retopo mesh?