Need help/guidance with normal mapping/displacement/texture baking/poly optimizations

[ngnht]

Hello.
First of all, I'm a complete noob: the first time I heard about Blender was early September this year.
The other 3D software I've used before was ZBrush, but it was just for fun sculpting, nothing serious, so very limited knowledge of Blender and ZBrush.
My specs are:
Lenovo y580, i7-3630qm 2.4Ghz CPU, gtx 660m 2GB GPU, 8GB RAM.

I'm doing a college project; my goal was to create two fairly detailed creature models and animate them.
I've been following a series of tutorials on Youtube by Hokiroya on creature modelling and got to the stage where I've completed the sculpt and barely finished unwrapping it.

The main issue I have right now is that I need to transfer the detailed texture/maps onto the lower-detailed model, but texture baking takes days.
I don't know what I should do to optimize my models, as I don't know how to use Decimate modifiers.
Also I don't know what to aim for in terms of time, how much it should take with my hardware. I know it's not powerful, given it's a 2012 laptop.

The issues:
- The sculpted model at highest level is at 16mil tris, I have no idea how it ended that way.
I have made a mistake of merging teeth and spikes with the model at the sculpting stage, I suspect this is the main issue and the cause of these excess tris.
My save files take up to 1GB!

I have another model that I've made using Blender+Zbrush+Meshlab, it has colours that show in Blender, it has 4mil tris and I'm willing to give up on the colourless 16mil one.
I've tried baking the 4mil-tris model's texture onto the low-poly one, but it takes 40 hours if nothing interrupts the process (the most I've gotten is 16% after 7 hours, and it got interrupted)

I saw some advice about how using Substance Painter is what I would want to use in my case, but it crashes every time I import my model from Blender; registry tricks don't help either.

- Vague understanding of how UV unwrapping, Normals, and Displacements work.

- Even If I'm following a tutorial closely, I still don't know if I'm doing the right thing, if I've missed anything, and I'm unwilling to anxiously spend days watching the progress bar only to find out that I baked maps wrong.

Any help would be greatly appreciated.

[ngnht]

Автор сообщения: The Renderer

This gap does not appear in Blender before you export it to ZBrush?
How do you export it? Do you use the plugin or a file (which format)?

It looks like some problem with the symmetry/mirroring. One of your pics looks like you are using a mirror modifier in Blender, is that correct?
If yes, did you export the whole mesh or only half of it to ZBrush? If only half of it, try with the complete one. If it was the complete one, make sure the geometry is right after applying the mirror modifier.

There was no gap prior to exporting from Blender, but there was an obvious seam due to unwrapping iirc.
I exported it using an .obj

When I exported it to ZBrush, the whole mesh was exported, it looked the same as in Blender, but then I applied subdivision levels in ZBrush to have higher resolution for applying alphas and the gap appeared.

[still__alive]

That sounds like maybe the mirror modifier was not applied to your mesh when it was exported from Blender. There is a checkbox in the export settings to apply modifiers that must be checked or they won't be applied when you export.

[ngnht]

Автор сообщения: still__alive

That sounds like maybe the mirror modifier was not applied to your mesh when it was exported from Blender. There is a checkbox in the export settings to apply modifiers that must be checked or they won't be applied when you export.

Hrm, okay, thanks, I get the idea.
I'll try to export my lower-poly mesh with freshly applied normals, this time with mirror mod applied either in modifiers or in export settings, don't want to lose the sculpting details.

If that doesn't work, guess I'll have to apply alphas all over again. It's a little annoying, but it's great to feel that the stuff that used to take a week now only takes an hour or so.

[still__alive]

Автор сообщения: ngnht

Автор сообщения: still__alive

That sounds like maybe the mirror modifier was not applied to your mesh when it was exported from Blender. There is a checkbox in the export settings to apply modifiers that must be checked or they won't be applied when you export.

Hrm, okay, thanks, I get the idea.
I'll try to export my lower-poly mesh with freshly applied normals, this time with mirror mod applied either in modifiers or in export settings, don't want to lose the sculpting details.

If that doesn't work, guess I'll have to apply alphas all over again. It's a little annoying, but it's great to feel that the stuff that used to take a week now only takes an hour or so.

Oops, I didn't fully think that through. I realize now that there is an error in my logic - if the mirror modifier was not applied, you would only have one half when importing the .obj into zbrush. So it can't be that simple.

My other thought was that the part that is disappearing is because of your normals being inverted, but this makes me doubt that as well:

Автор сообщения: ngnht

When I exported it to ZBrush, the whole mesh was exported, it looked the same as in Blender, but then I applied subdivision levels in ZBrush to have higher resolution for applying alphas and the gap appeared.

This makes it sound like something is wrong with the mirror modifier, but it can't be that it isn't applied because you should only have half the mesh. I think. It is almost like the mirror modifier is there, but not merged at the center(clipping setting issue or something), and when you apply the subsurf in Zbrush the smoothing that is applied pulls those verts slightly back causing the gap.

[The Renderer]

Автор сообщения: still__alive

It is almost like the mirror modifier is there, but not merged at the center(clipping setting issue or something), and when you apply the subsurf in Zbrush the smoothing that is applied pulls those verts slightly back causing the gap.

Yeah, that sounds likely. ngnht, make sure merge and clipping are turned on in your mirror modifier. And after you apply the modifier, check to make sure the vertices on the mirror line are actually connected. You can hover over part of the mesh in edit mode and hit "L" to select all connected vertices. If it only selects half of your mesh, they two halves are not connected.

[ngnht]

Автор сообщения: still__alive

This makes it sound like something is wrong with the mirror modifier, but it can't be that it isn't applied because you should only have half the mesh. I think. It is almost like the mirror modifier is there, but not merged at the center(clipping setting issue or something), and when you apply the subsurf in Zbrush the smoothing that is applied pulls those verts slightly back causing the gap.

Автор сообщения: The Renderer

Yeah, that sounds likely. ngnht, make sure merge and clipping are turned on in your mirror modifier. And after you apply the modifier, check to make sure the vertices on the mirror line are actually connected. You can hover over part of the mesh in edit mode and hit "L" to select all connected vertices. If it only selects half of your mesh, they two halves are not connected.

Yes, when I applied the mirror in Blender the latest time, that is, before exporting, even with clipping and merging options activated, the middle vertices acted weird: the two halves were connected, but there were 2 specific vertices that somehow just wouldn't merge with each other, and would open up a triangular opening if I selected them and moved around.

And even after some manipulations they did connect, if I Alt+Selected the middle line along the
whole length of the model, then moved it intensively with my mouse, continuously to one side over the edge of the screen, this selected line would eventually move to the side gradually instead of staying in place and moving only at Y-axis.

I mean, instead of moving up-down and forwards-backwards, it would also gradually move left-right, while with both halves still being connected.

[The Renderer]

Автор сообщения: ngnht

Yes, when I applied the mirror in Blender the latest time, that is, before exporting, even with clipping and merging options activated, the middle vertices acted weird: the two halves were connected, but there were 2 specific vertices that somehow just wouldn't merge with each other, and would open up a triangular opening if I selected them and moved around.

And even after some manipulations they did connect, if I Alt+Selected the middle line along the
whole length of the model, then moved it intensively with my mouse, continuously to one side over the edge of the screen, this line would eventually move to the side gradually instead of staying in place and moving only at Y-axis.

I don't understand that last part but you have to make sure they are all connected before exporting. You can do the following to find any non-connected parts:

Go into Edit mode, deselect everything, then pick Select -> Select All by Trait -> Non-Manifold (or Shift-Ctrl-Alt-M). That will select all vertices that are adjacent to a boundary, i.e. not connected. Any vertices that are selected and that are not at an intended mesh boundary you'll have to fix (=merge with another vertex).

[ngnht]

So I have created a normal map, applied textures, it's not perfect, but will do. But they both appear only in Rendered/Material viewport shading. Can I make it so that I can see normals and textures applied to my low-poly model in Solid mode?

[The Renderer]

Автор сообщения: ngnht

So I have created a normal map, applied textures, it's not perfect, but will do. But they both appear only in Rendered/Material viewport shading. Can I make it so that I can see normals and textures applied to my low-poly model in Solid mode?

No, solid mode (as the name implies) can only show your models as solid colors. Is there a specific reason you need the maps to show up in solid mode?

[ngnht]

Not really, I'm just concerned about how it will all work when I'm going to start animating it.
I need to bake an animation so that the render doesn't calculate every single deformation, is that right?
Also, I should be doing all this in Cycles render, right? I had troubles baking maps in Blender Render, and Blender Render's rendering viewport doesn't show anything, too.

[The Renderer]

Автор сообщения: ngnht

Not really, I'm just concerned about how it will all work when I'm going to start animating it.
I need to bake an animation so that the render doesn't calculate every single deformation, is that right?
Also, I should be doing all this in Cycles render, right? I had troubles baking maps in Blender Render, and Blender Render's rendering viewport doesn't show anything, too.

I'm no expert when it comes to animation but I don't think there is any point in baking the animation as long as you stay in Blender. You usually only do that to export it to some other software where the bones and other Blender specific parts don't work. Or if you have computationally intense physics based animation (cloth, rigid/soft body etc).

I strongly suggest Cycles, yes. Blender Render is severely outdated and shouldn't be used anymore. In my opinion.
What you could also do is download 2.8 and use the new Eevee engine that allows realtime rendering (like a game engine). It's less precise/realistic than Cycles but it probably would be more than enough for your purposes. The materials are identical between Cycles and Eevee, so you can easily switch from one to the other as you see fit. Just three things to keep in mind if you try it: 2.8 is still in Beta, so save often. You cannot open 2.8 files with 2.79, so make sure you keep a backup. And while the materials are identical, the lights work differently, so you may have to create a different lighting setup for Eevee and Cycles.
An added benefit would be that you can work with Eevee turned on and see the applied normal maps and materials while you do so.

But of course that would mean learning 2.8 and Eevee, so maybe stay in Cycles for now, and if your final render times are infeasible you can think about switching.

[ngnht]

Yes, I've downloaded 2.8 some time before, but quickly realized I couldn't do anything because of the brand-new interface xD
So I just put it off for now.