Mesh scale in baking texture maps, workflow question

GreenFirefly

Hello!
I'm trying to get better understanding of workflow for game characters.

I sculpted model in zbrush and made retopo in blender. For this I used decimated export of the model. Now when I'm moving towards baking maps I realized that my scale is still wrong. Made some research and for some specific maps it seems the real scale is important when baking in Substance painter(?)

So my question is that at which state I am or was supposed to convert to the real scale?

As now my model is 4 m tall, sculpt and retopo. I was on purpose sculpting on bigger model, just that my brushes work well. But I guess I should have converted sculpt to real scale before exporting for retopo? I find zbrush scale a bit hard, so is there any good for workflow how to scale the model to the specific size in there. Or does anyone have any ideas how should I fix my scale now as I have progressed already this far? I'm not sure in which program or how I should scale that models stay the same. 

poopipe

Ideally you'd sculpt at the correct scale in the first place .  Ive seen people  import a reference cube or object to set their tool scale before starting to sculpt - not sure if there's a better way now.

Scale can affect  certain bake types eg. Ambient occlusion, thickness, anything with spatial parameters really . You can generally tweak numbers to get a good result - it only affects your ability to maintain consistency with other assets. 
Normals shouldn't be affected at all since the stored values are normalised.

The issues with Painter relate to the unit type in your fbx file. 
When I logged the bug in 2017 painters baker ignored the stored unit type and assumed centimetres so if you exported a file that is using metres as a base unit without conversion to centimetres the world space options in the bakers react badly. 

Anyway - with whatever you're making....
It's not a big deal and there's no need to start again. Just scale it as early in the process as you can without causing a load of rework and remember it for next time.

GreenFirefly

Thanks for your explanation! I made it in my head a lot harder than it actually was.

Now I'm only having issue with fbx export. Which goes a bit off topic but... after playing around with zbrush's scale master, I got it to right size. Or at least almost....

When I open fbx I exported from zbrush in Blender it shows that the scale is 0.01, but it is right size. If I apply it everything is ok. 
But the fbx itself is still too small. I can't use it for baking in Substance Painter without this process first bringing it to Blender, applying and exporting again.

So I think there is one small button somewhere which I have forgotten to press. Not sure if this is zbrush or blender problem, as both of them seem to know what the right size should be. Playing around with scale master didn't change a thing, same happened always. If anyone has encountered this problem, I would like to hear how to solve it. 

poopipe

zbrush is a bit of a dick in my experience. 
as a result I always set the meshes up  (i.e zero their transforms, line them up, fix normals etc) in max / maya / whatever before exporting again to bake in painter.