masking options / masking from photo

[lukasso]

hello.

Can someone share masking techniques from photo ?
I know that I can get photo as texture, then get it to alpha and to add to simple plane to mask with alpha and then inflate or offset with deformations. I can do that with couple of photos with different effect to make quite good relief.

but the object is so thin that I cannot print it…

when I don’t want it to by flat…for example I would like to add it to the box…well now it changes everything.
Box have more sides than plane so I cannot control how to add alpha with previous way just to one side…so I cannot get nice displacement from for example 3 photos with different details sharped…

I’ve also tried getting color from spotlight and then mask from color and deformation, effect is ok but not as detailed as I would get from 3 prepared photos with different parameters. And I cannot match 3 spotlight photos to exactly same place, right ?

any one have some more ideas ?

[Spyndel]

but the object is so thin that I cannot print it…

Let me address this first issue, rather than the second which is more complicated. If you’re getting results you’re happy with doing this and thickness is the only issue, it’s probably easier to just add some thickness to that plane rather than mess around with the other stuff.

If your shaped plane is high poly, which it probably is, the easiest way to do this is probably just to mask everything and create a Tool > Subtool > Extract with a negative thickness (will then extrude towards the bottom leaving top unchanged ) with smoothness set to zero (prevents distortion of detail), and “double” disabled (will only extrude in one direction.)

The resulting mesh will now be 3d, with separate, clean polygroups on the top and bottom. From here it is an easy matter to mask all but the bottom polygroup, and use gizmo to pull it down far enough that you can cleanly slice off any unwanted detail on the bottom with the Trim> curv brush, resulting in a nice flat bottom base and a sculpted top. Likewise you could simply delete the bottom polygroup, and fill the hole with Tool > Geometry > Modify Topology > Close hole.

I made this illustration for a user with another issue, but it shows what Im talking about:

[lukasso]

well thank You, I can say that it obviously works for what I needed

[Spyndel]

Ah yes, very nice.

Let’s get rid of those jagged sides for a cleaner print (hope you have access to a really nice printer BTW–most consumer grade FDM printers will not be able to capture that level of fine detail).

1. Extract extrudes along normal facing, not in a straight direction. So depending on the condition of the polys at your edges, this may result in “grooves” that will become more pronounced the thicker the extract is. So what you want to do is set your extract thickness as thin as possible before pulling it down.

2. If you find this makes it difficult to isolate the resulting polygroups, make sure you are very comfortable with the visibility and masking shortcuts. So in this case you would shift-ctrl click on the bottom polygroup to hide all but that polygroup, shift-ctrl click it again to hide that polygroup and show everything else, then mask everything visible by ctrl clicking in empty canvas space (assuming there is no existing masking). Or you could simply ctrl-shift-click on on the target polygroup in Move mode, which will do the same thing in a single action.

3. Just doing #1 should eliminate a lot of the distortion, but the sides may still not be perfectly flat. So just after performing the extract, before pulling the bottom group down, activate the Clip Curv (not the trim curv) brush, and use it to flatten the sides. This will require you to clip off a small but not significant portion of each side in turn. Maybe a millimeter or so, depending on how uneven the edges are.

---

Mind you, if this is a dealbreaker for you, and you need to place this relief on a very specifically sized 3D object with no deviations or trimming of the sides, we can also get that done. But from what I understand of your workflow this is going to involve layering multiple images perfectly aligned over one another. This is probably going to require UVs which is a whole other can of worms that doesn’t need to be opened if you can get results you’re happy with doing this.

[lukasso]

well I don’t have nice printer just consumer grade and it was a hard head bump…I have to change my technique I knew that I won’t be able to catch all the details, but I was more hoping it will be merely visible building so now I’m thinking to do it not so fast way

can You please elaborate ? I see that You obviously know what to do ^^
in point 1 : “Extract extrudes along normal facing, not in a straight direction.” or maybe this is exactly what you said next “So depending on the condition of the polys at your edges, this may result in “grooves” that will become more pronounced the thicker the extract is. So what you want to do is set your extract thickness as thin as possible before pulling it down.” ? if yes than it is understood

thanks

[Spyndel]

Yes, that’s correct. Make your extract as thin as possible. The thicker the extract, the more pronounced those grooves will become.