[Solved] Best way to generate grayscale/height maps from 3Dcoat

[Omni-Moulage]

Hi everibody,

With 3DCoat it is very simple to create a low relief model from a grayscale picture.

But I would like to find a way to generate a grayscale picture from an existing 3D model.

Somebody could help me for that ?

This morning I prepared a short video to show my method but the result is not tottally correct because the relief i created missing round shapes.

All help will welcome

2021-10-30 07-51-01.mkv

 

direct link if you prefer: https://photos.app.goo.gl/vAhhpgGANgZThQWz6

Edited October 30, 2021 by Omni-Moulage
video link added

[Carlosan]

Hi

Your method is correct, remember to save it as 16bit scale

try render using black as background color, fine tune light curves on any external editor and blur borders to get smooth transition between silhouette borders and background

[Carlosan]

Also can create images using Creating Brush alpha using 3d-model (On brushes Panel)

And then export it

--------------------------------------------

This video is outdated, but procedure is still the same

 

[sprayer]

53 minutes ago, Carlosan said:

Hi

Your method is correct, remember to save it as 16bit scale

try render using black as background color, fine tune light curves on any external editor and blur borders to get smooth transition between silhouette borders and background

Are you sure is this correct? He wants zdepth map, but rendering composite pass by default. But i just test 3dcoat rendered all passes  the same, looks like a bug.
3dcoat have depth pass not sure if it's the same zdepth. 

Just tested in 4.9 it's really a bug with passes, but depth pass looks just black, do not know how to use it, in zdepth you should set distance to bake depth to black\white color

Edited October 30, 2021 by sprayer

[sprayer]

Okay i found out it working but only with fog settings and it needs to be inverted so still it's not zdepth, maybe we should ask this feature.

Edit. It is also works in 2021 with fog, but i found it works in different way, i cannot achieve the same result as in 4.9 to have on model depth gradient from white to black, just in gray range.

Note you have to change shader. it won't work with matcap shader...again

 

Edited October 30, 2021 by sprayer

[Carlosan]

You are right, but currently is the only way because depth render have a bug.

Anyway, a tool equivalent to MRGBZGrabber will be the best solution.

[Omni-Moulage]

Thank you very much for taking the time to answer me.

After several tries, I decided to use "Fog Mask" then an external editor.

To begin with, I took 19 photos by varying the value of "Fog Density" (from 810 to 500)

Then from the external editor I compiled all the images to create a single inverted one.

The result is better than this morning but I think it can be improved a lot. (I just added two spherical shapes for the eyes)

 

 

 

the relief is poor :(

final result on a medalion

 

[sprayer]

It is poor because 3dcoat save in 8bit image, this is very small to store gray colors, only 256 colors in full range, you need atleast 16bit or 32bit image. Try to save it from photoshop

So this depth map is useless if you cannot save it in better quality. 

@Andrew Shpagin Can you take a look on this? zdepth map is pretty useful feature

[Carlosan]

Export depth along Y will be very handy.

* Remember that the camera used for the screen capture is top view

- Video Example

 

[sprayer]

@Carlosan Maybe i don't understand but how to increase image bitrate on save? Because 8bit (256 colors for alphas blacks and white) is not enough for displacement especially if you cannot to set it range between black and white because of fog restriction, you can see on screenshot from topic starter it is visible steps in depth. All displacement map saves in 16 or 32bit per channel

[Carlosan]

Save as TIF to get 16bit precision 

 

Or EXR file format to get 32bit floating precision

[Omni-Moulage]

After a lot of trying, I'm a little confused now.
I could not find better than to make several images by varying the value of "Fog Density" (especially to detail the eyes of the bear)
Are you sure that the bit level should exceed 8 ?
Because when I take a look at the precision of the first frame I show on my first post, the precision is only 8 bits.

[Carlosan]

Hi

Follow this steps please

 

[sprayer]

1 hour ago, Omni-Moulage said:

After a lot of trying, I'm a little confused now.
I could not find better than to make several images by varying the value of "Fog Density" (especially to detail the eyes of the bear)
Are you sure that the bit level should exceed 8 ?
Because when I take a look at the precision of the first frame I show on my first post, the precision is only 8 bits.

Yes to avoid terraces like this

you need 16bit format

 

 

I tested as Carlosan said, you can save more bit(what is strange) only via export.

So your steps

-in sculpt room rotate model to look on top

-go to render room choose depth pass

-turn on fog and adjust a bit to see it in viewport

-return to sculpt room, file->export->export depth along Y, choose tiff or exr format, make sure to mark checkbox

 

and save image, as carlosan said tif will be in 16bit, exr in 32bit.
This is really strange steps to me for exporting zdepth

But note big object may looks bad as you can see on my example. it requires big value of extrusion to looks rounded, or it will be flat like this

So small details like ornaments works best

Edited November 1, 2021 by sprayer

[Omni-Moulage]

All right Carlosan and sprayer, I thank you for explanations and help.

I will follow your recommendations.

Have a nice Halloween