Selfie Styklet Part 2
Welcome back for part 2 of making a selfie Styklet. Last time I wrote, I said I wasn’t satisfied with my results and was going to try something else. One thing that stood out to me was that at the scale I was working at, the details were not coming out well. The overall result was poor, so this time I'm allowing myself to scale up a bit and make a larger print.
I decided to try out a technique of using a "heightfield from the image" to see if I could get a decent representation of my face from the image. This technique creates a surface or mesh based on grayscale values of the colors in an image, essentially assigning a height to each of the values. This reminded me of the technique of creating "lithophanes".
If you’re wondering what a lithophane is, it's an old technique of etching or molding a scene in very fine porcelain such that when it's backlit, the image can be seen in gray scale on the porcelain surface. To learn more: https://en.wikipedia.org/wiki/Lithophane
I can’t imagine the difficulty of producing such fine engravings and the skill of the artisans was incredible. Here is an example from the above-mentioned Wikipedia article:
I went online and found a cool site called www.lithophanemaker.com where you can upload an image and it will create a lithophane for you. Here is the interface with my picture and the values I selected to create my own lithophane.
I tweaked the variables a little bit (the final ones shown above) and this was my resultant lithophane:
As you can see, this is etched into the surface. It is essentially a negative image, which if you backlight, gives you a neat positive image through the plastic. I figured I can take this file into Rhino, and do a Boolean difference operation to see if I can get a positive image.
This was the result of importing the mesh into Rhino, creating another mesh volume, and doing a mesh Boolean difference to get a positive.
I then imported my outline of myself so that I could use that to cut around the border of my face. But, all the mesh Booleans didn’t work, so I had to tediously select mesh facets to extract and delete (as an aside, when you use the extract mesh face command in Rhino, you can type in selection brush, which allows you to use the selection brush to paint around the contour you want to select).
This is the result:
Honestly, at this point I abandoned this approach as I could see that the result would end up being hideous, and I’d already sunk hours into getting to this point— I didn’t want to waste any more time.
I decided I would try again with my picture and outlines, but this time make a sort of contour map of my face.
I started off in photoshop to trace out some rough paths with the paint brush set to a hard brush. My goal was to create a sort of contour map of my face so I could create a relief. There is nothing of the skill of the lithophane engravers here:
Ultimately I want to take these contours into illustrator to make vector paths which I will then export into Rhino as a DXF file to use to create my relief. I made the contours in photoshop because I find it easier to trace around the image using a graphics tablet, as it is more natural than trying to make the vectors outright in illustrator. To make the export into illustrator easier, I right clicked on the pane of the photoshop layer on which I had created my brush strokes and clicked on select pixels. Then I went to the paths pane and converted these to paths, so that I can take these paths into illustrator to clean them up. The image below is of the contours I created in photoshop, converted to paths (as you can see, they are not very pretty, and they have a lot of control points).
To get the paths into illustrator you have to go to File->Export->Paths To Illustrator. This gets you the paths as vectors back into Illustrator. While this is a nice trick, unless you use a fine and hard brush, you’re going to get mixed results. Even with what I did, the results required quite a bit of clean up, which was really tedious.
This is the vector result in illustrator:
So, now I can take my paths into Rhino and extrude them, and hopefully with the contours the result will look a little better!
Here is what the 3D model looks like.
As I mentioned earlier, I made the envelope of this sticker larger so that the detail can print a little clearer. Previously I was at a width 22 mm of and a length of 43 mm, now the sticker will be a width 31.8 mm and a length of 60 mm, with the total height currently at 2.2 mm. I predict that the sticker will need to be extruded a bit higher in order for the features to read better, and perhaps also be scaled up a little, but we’ll try a test print anyway.
The result is absolutely horrific!! I look like a true plastic surgery disaster.
What can I do to salvage this? I’m going to try to clean the contours up a little bit and extrude the contours a bit higher, as the contours aren’t reading very well.
I went back into Illustrator and cleaned the contours a little- especially the lips, as Alex told me that they were particularly disturbing. As an aside, Alex is very friendly in her criticism. When I sent her the 3D file and she fired up the Styklet machine to print this out, she sent me a message saying: “The new face is interesting. I think it’s the lips that make it scary.” A note to everyone, when someone says what you made is interesting, they’re definitely holding some far more poignant criticism from you. If we translate Alex’s quote, what she really was saying was, “Holy mother of god, Eric, your selfie sticker is a nightmare from which I will never awaken.”
So these are the new contours:
As you can see, I cleaned the lips up a bit, trimmed the contour between my nose and brow, added some detail to the right cheek (which I’m not sure will work because it’s not symmetrical with the left), and I changed the detail under the eyes.
The 3D model, which I extruded higher, and trimmed down the hair to have a bit of stepping so that the sideburns wouldn’t be at the level of the widow’s peak, is shown below. I also ended up not adding the detail on the right cheek, because, as I predicted, it looked terrible. I also got rid of the dimple above the chin, as it didn’t read well. Lastly, I made the sticker slightly larger, from 31.8 x 60 mm x 2.2 mm, to 38.7 mm x 73.2 mm x 6.2 mm. I already told you I would extrude it higher, but I also scaled it up a bit, for reasons I’ll let you know soon.
This is the 3D model, and you can see the modified contour map next to it:
So, I sent this off to Alex to get a 3D print of it.
The results are in:
While it’s better than the previous one, I must say, this portrait doesn’t quite suit me. Moreover, it still has the dimple above the chin, which I was certain I had modeled out of the part, so I can’t understand why that it still there… Mystery…
Here’s a side by side of the progression of the selfie Styklets:
I must say, I’m not satisfied with how this one (or any of them, for that matter) turned out in the end, but I’m glad you’ve taken this journey with me. I may post a part 3, as I have another idea for how I might make this. Do you have any ideas you’d like to share? Here are my main takeaways:
Start with a good photo under good lighting.
The results from the various automated services I’ve found, while impressive, aren’t suitable for printing at a small, sticker size scale.
Making the sticker larger, and the features more pronounced (eg extruded higher) will result in a more legible sticker.
Many times, starting from scratch is better than trying to polish something that isn’t quite working.
That last one said, if I do remake it for a third post, I will start from scratch with a proper photo.
Finally, I mentioned that I made the final sticker a bit larger and that I would tell you the reason why. I suspected the print wouldn’t come out to my liking, as I could tell from the model, but Alex said that the eyes were ok. She threw one of our facemasks on it to prove her point, but the facemask was a bit too large for the sticker. I scaled up the 3D model so that the facemask would be a perfect fit, as you can see here:
Thanks for reading, and feel free to add your thoughts in the comments section, or come back and see us again. Perhaps I’ll finally get a nice result!