Count Joshula

uncheck Voxelize Before Quadrangulation, and it will appear

If the mesh you created in Groboto3d is of acceptable polycount, then just use that mesh as the retopo mesh to bake the details.

Okay, I found out what is happening, which I didn't quite realize. If you export using "Diffuse" for a texture, the color will be darkened where ever there is Metalness painted. You can see the image below for descriptions (Hovering over stuff in 3d Coat often gives you a description). What seems weird to me, is that changing the Texture Workflow doesn't seem to do anything for me. "Color (albedo)" seems to get the color information despite being set to "gloss/specular" workflow. Anyway, if you are using Metalness and your paint layer's Metal Opacity is above 0%, then Diffuse will be darkened. So, you need to export "Color (albedo)" and not Diffuse. If you are not using Metalness, or your Metal Opacity in your paint layers is set to 0%, then you can export with Diffuse and still receive color information. If anyone wants to clarify or expand on this, please feel free to interject.

A couple more things. Even though in my screenshot it says the preset is "Unity (Standard)" . The preset isn't 3d coat's original preset, it's my own that I use for the standard shader. Also, when I export using 3d Coat's "Unity (Specular)" preset, I get the black diffuse texture like you do, but it's because the color is being stored in the "Specular Color" texture, and not the diffuse. So, I think that something is similar is probably happening to you. But, depending on your workflow it still renders in Unity fine with the black diffuse as long as color is being stored in the Specular. (see below) However, when I export it with the exact settings Carlosan has in the screenshot above, the diffuse exports with the color, so I'm not entirely sure what would cause it to be different for you IF you followed his export settings exactly.

No problem, let me know how it goes

And, here are my settings in 3d Coat. This is how I typically export when using the Unity Standard shader.

Not sure what's going on, it worked instantly for me. Here's a screenshot inside Unity:

The presets are only going to change what textures are exported, not how they are exported. So, 3ds Max vs Unity "color (albedo)" texture shouldn't be any different. That being said, what you are experiencing does seem a little weird. Would you mind uploading your project? Also, what will this be used for? Unity? Because I have a decent amount of experiencing exporting to Unity. (Also C4D and Octane, but you didn't mention those at all)

Ya, that's not how I export. I go to File > Export Object and Textures. So, go there and really examine all your options there and get familiar with it. Note: 1. You can uncheck Export Geometry if you don't want to export geometry. 2. You can save presets for your specific workflow.

The streaks between faces is padding, that should be okay. If you are not using a PBR lighting system, then you should export "Diffuse" not "Albedo"

https://www.youtube.com/user/AlienMinefield/videos

I would have to know a little more about your project. Are you importing a model that's already UVed? If that's the case, just select the brush tool, then select the Smart Material and paint the parts you want, then switch to another Smart Material. What you're asking seems realllly straight forward. So, I'm not sure what you're having trouble with.

Basically you're going through the autotopo and it's not calculating properly, so it doesn't output a mesh. 3d Coat isn't good at telling you that it failed. But, that's what's happening. Your mesh is probably too complicated for it. I've been using 3d coat for awhile now, and I just don't think you're going to be able to do it the way you are trying. If you want good retopology, you'll have to manually do it. Not to mention, like Javis mentioned, the topology already looks good and low poly.

Ya, so the scene is very large. It's like if you were to stand at the top row of a football stadium to view a coffee cup in the center of the field. It's a terrible way to view a coffee cup, but the coffee cup is still to scale. So, for some reason when you import an object, 3d Coat is making the scene really big, and that makes your object really small. Why it does this I have no idea, but it does the same thing to me as well. So, there is either a reason for this, or it's just another quirk of 3d coat (in which there are many).

What I mentioned would scale all the islands at once, not individually. It sounds like you want to scale all the UV islands from each individual UV island's center point, because you left too much padding between the islands. But, I think you're going to have to just scale all the UVs at once, then adjust the spacing manually. You might be able to do what you want with other 3d software, but I don't think you can do it in 3d Coat. Anyway, that's all I got, so hopefully someone else chimes in. Good luck!