[SOLVED] Bas-relief portraits? Anyone succeeded?

[cnczane]

Have any of you out there in MeshCAM Art-land tried to model a human head from a photograph for a low-relief carving?

With all the knocking I've done to my own head trying to find or invent a straightforward (I gave up on easy) way to do this, I'll soon be able to model it with a flat board...

I'd like to offer "Portraits by Bonzo!", or something like that, to the buying public.

Anyone? (Someone to try.)

BFtinker.png (293.89 KiB) Viewed 5945 times

Thank you.
--
daZane

[Randy]

Bonzo, every couple of years I do some searching which has in the past been fruitless.

Most "bas relief" software is nothing more than producing a height map based on the grayscale values ( http://www.ransen.com/phototomesh/Pictu ... relief.htm ), which MeshCAM does natively.

But on something like a face, the brightness on broad curved surfaces is more like the derivative of the slope of the surface at that point. I have thought in the past that you could start at a corner and integrate height along the scanlines based on the grayscale values, but I quickly discouraged myself from that line of thought. There are also literal shadows involved (hair shading other hair and underlying surfaces, etc.) so the integration technique might be workable on something like a sphere or egg, but not much more.

In Googling today I ran across this (which I have not read) http://www.researchgate.net/publication ... uman_faces

There is an article at http://www.sciencedirect.com/science/ar ... 0313000283 which I don't have access to but looks promising.

There is a semi-manual method at http://forum.vectric.com/viewtopic.php?f=7&t=18894 where he biases the gray levels to give the gross shaping.

If your own research does reveal a solution, I'd appreciate hearing about it. I've spent a non-trivial number of hours (so far) taking this image, which was never a 3D sculpture

Wings grayscale reduced.jpg (245.16 KiB) Viewed 5942 times

and modeling it in 3D, so far

zephyrus-rendertest4.png (492.79 KiB) Viewed 5942 times

I am definitely not an artist--just the "what's in front of what else" depth logic is about as much as I can manage...

The image is from the mid-1930's, so I'm trying for an Art-Deco style relief that might have been carved on a building facade.

Randy

[cnczane]

[Ahhh, my chrome browser just crashed and ate my reply. If the following is not Brilliant!, well, you should've seen what I wrote before! I was laughing. I was crying. I was uplifted. I was... well, you get the picture.]

Thanks Randy. Google search being the watered-down, pat-on-the-head shadow of its former self, I think it's giving all of us the same-old same-old. (I'm starting to be curious about how to search the dark net... In fact, these days, I often try to jump to the 100th page of the search results.)

I don't think Wu's group is onto anything, really. I downloaded one of their "depthmap" results and fed it into MeshCAM. What MC saw was a typical lithophane. Similarly, I think the photomesh people are just separating a photo into a cookie-cutter outline, which they raise, and a high-pass filtered version containing the edges which they just paint on the cookie. "Bas-relief-like." I would call it.

I also saw M. Rabin's Herculean effort with his pup's model. It reminded me of this, that I learned of recently:
http://twistedsifter.com/2013/11/worlds ... g-chunhui/
in terms of requiring a certain level of "commitment." :^)

Of all the software I've seen so far, I thought MeshCAM Art seemed the most promising, but I thought, if so, surely, someone's done it? [Did you do SuperFTD-Man with MC A?]

I had some correspondence with the proprietor of my3dscanner.com (now defunct) Pavel Prozor (in Czech Republic?) who said he was going into the bas-relief-from-photos business, and his results looked promising--making me think he had actually found a method, but alas, he too no longer answers the bell at my3dscanner.com.

I'd give it a try, but MC Art has that 30-day limit and how-it-goes at my house is: settle in to give it a try... [interruption]... [BOOM]... it's 31 days later...
--
David, Zane of CNC

[Randy]

Not quite, David/Zane/Bonzo. FTD-man is Hermes/Mercury and this is Zephyrus, personification of the West Wind. And sorry, I am using a conventional 3D CAD program to model him. I stalled out on his facial details last October and haven't gotten back to the project yet. But I think that I'm not doing the reliefs quite properly for bas-relief, especially on the wings. I have multi-megabytes of reference photos of coins, medals, building carvings, etc. but I think I might need to actually section a few coins (lacking a high-resolution 3D scanner, which would cost far more than a few sacrificial coins...) to see what the feathered wings' cross section actually is.

Randy

[cnczane]

BTW, here's what I meant about Wu's group not exactly having discovered the Lost-Dutchman-mine of 2D conversion; it has caught a lot of the aspects of a depth-map, but has some of lithophane as well (nose, hair). (I changed the background from black to the same gray found along the edge, and then normalized to stretch the values for maximum dynamic range, in GIMP of course.)

Caesar_afterWuetal.jpg (55.67 KiB) Viewed 5932 times

--
David

[boltz]

If I were trying to accomplish this, I think my first efforts would involve using Blender. I would first do a rough approximation using grayscale displacement and then retopologize and use the mesh modeling tools to fine tune the result.

[cnczane]

@boltz

My thoughts regularly turn to Blender and its -alikes. However, Blender represents a huge time commitment to learn it and, in the end, still requires one to develop, through practice, an artistic sense.

My thinking is that since, no matter which tool is chosen, one is going to have to spend hours developing the art sense, it would make sense to spend that time in a tool that didn't take up a lot of time itself. I wondered if MeshCAM-Art had been taken into non-geometric areas. Or if it had been tried, and found unsuitable.

And I fully admit that, once mastered, very little time is spent learning a tool.

Thanks!
--
David, CNC-zane
BTW I found this (and Sculptris) to be more "approachable" than Blender:
http://stephaneginier.com/sculptgl/

[AdPrinter]

I haven't been on this site, for some time now. And saw this post. I find this subject to be of the greatest interest, in using MeshCAM Art. I have been working with MC Art for several years now, and routinely use it to successfully carve many artistic pieces. Thru many trial and error sessions, I have gained a comprehension for how to shape the various artwork pieces into the desired shapes, using MC Art. As hard as it may seem to believe, I have only just gotten around to doing a serious attempt at sculpting a face from a photograph.
It is important to note here, so that anyone reading this is NOT misled: The "Photo" was simply used as the pattern, which was imported into Corel Draw, to trace and overlay with various closed-cell shapes such as circles, and bezier curves and assigning different colors to each, in an effort to "Shoe-Horn" them into the capabilities of MC Art! My first attempt, actually came out pretty decent. However, the subject was a photo of my wife, (who has forbid me from showing to anyone, since she is ashamed of her weight). She suggested that if I want to be showing photos of such carvings, that I do a self-portrait!
So.... that work is still in progress. But after having completed the first one (of my wife), the best description of it that I can offer is this: It provided an excellent "Foundation Blank" to work with, for hand-carving with a dremel tool. Although many hours were spent working with MC Art in an effort to digitally sculpt the piece, the actual results just did not produce the details as pictured in the MC Art preview window. This is due to my Stock size (11" maximum width or length), and tooling limitations, (1/4" dia roughing bit, and 1/8" dia finishing bit). The best advice I can offer, from this experience, is to GO LARGE! I have considered gluing multiple pieces of wood together, in order to have a blank piece of stock large enough to accommodate. However, for now, I am working within the limitations of my stock/bit sizes. (And finishing by hand with the dremel tool).
I will post the results, once I finish the self-portrait piece. The actual artwork used, for importing into MC Art has the appearance of a clown (this was necessary in order to assign contrasting colors to the various areas, for the purpose of using the Shape tool in MC Art to sculpt into the desired shapes). Have a blessed day! -Michael

[AdPrinter]

Just wanted to post a link to my facebook page, so that others can see some of my carvings.
https://www.facebook.com/michael.hobgoo ... tos_albums
Feel free to browse thru the various photo albums, which contain many of my carving results over the past five years or so.
Have a blessed day! -Michael

[cnczane]

Hi, Michael,

First, thank you for... no...

First, thank you for responding.

Second, thank you for the thoughtful guidance regarding how to use Meshcam Art to approach human sculpting. Your estimation reinforces my notion of how MC Art works.

Thirdly, thank you especially for sharing a link to your work. But, umm, how does FB work? I know I am the Very Last Person in the First and Second Worlds who does not "get" it, but when I followed your link, I didn't see your models as I expected.

Is there a form I must use to sell my soul to Facebook demons first? (If so, could you post a few of your best here?)
--
David "CNC" zane