Author Topic: $50 Material Scanner Project  (Read 3047 times)

Hey all! So it's bugged me that there's no easy cheap way to just walk around and scan cool surfaces using Substances new tools, so I made my own. It's not too hard or expensive to do! Figured I'd share the design here so that other people can make even better ones!

SHOPPING LIST:
Basic Soldering Kit (if you don't already have that stuff)
4 cheapo on-off switches and a project box
A sheet of black construction board
Black construction tape
some linear polarizing sheet (search for it online)
4 feet of daylight white led tape
any 12v source (a plug is cheapest... battery is cool because you can go outside)

MAKING THE SCANNER:
1) Cut out and tape the construction board so it looks like the one I have. Leave an opening at the top. You could also maybe use a softbox instead of cardboard? up to you!
2) Wire up the 12v source and switches so that the 4 led's can be switched off and on individually. I can draw this out later if someone needs more info.
3) Adhere the led strips to the inside of the glorious cardboard pyramid you made, like in the image
4) cut 4 strips of polarizer sheet, and then tape them over those led strips. IMPORTANT!!! Cut two lenghtwise, and the other two widthwise, so that the polarizer sheets all point in the same direction.
5) Cut another square of polarizer, and tape that over the top opening. IMPORTANT!!! Align it so that it's turned 90 degrees from the ones on the leds. You'll know it's rotated correctly when it seems to black out the lights.
6) Make whatever terrible (or fancy) thing you want to make it easy to connect your camera to this thing. I bet it would be cool to make a bracket that you can attach to your camera lens! I was too lazy. DO IT DON'T BE LAZY LIKE ME! BE A HERO. SHOW ME UP WITH YOUR SUPERIOR SKILLS. GET ALL THE LIKES.

TAKING THE SCANS:
1) lie it down on any surface so that it doesn't move
2) take 5 pictures: one lit from each of the four angles, and then a fifth with all of the LEDs on at once. PROTIP: Use a remote to snap the picture! If you're using an iphone, the + button on the headphones works great!

IN SUBSTANCE:
1) Just load up their premade scanning node presets, turn off whatever prefiltering they try to do, and that's it!
2) (OPTIONAL) Instead of using their color output, pipe in you OWN color using that full-lit example. I personally liked the result out of that better.
3) Keep clicking buttons and shuffling nodes around for another couple hours so your can bill the client for a full day's work.

And that's it! So easy.

STUFF THAT CAN MAKE THIS EVEN BETTER:
1) I'm not getting specular out of this because I'm lazy, but it's not hard to do. Replace that top polarizer with something you can rotate 90 degrees, and then take another set of photos. The difference between the two images is your specular!
2) You could automate this entire thing using an arduino instead of my luddite idiot-switches. You would seriously look so cool if you did that. Do it!
3) The whole thing is pretty light, and could easily be attached to the end of a camera, and then that camera could be on a tripod. Then you could take pictures of walls and ceilings and whatnot!
4) Iphone camera works shockingly well here, but a real SLR would do even better of course. No big deal... just a matter of making a different adapter on the end! Keep in mind if it's a mirrored SLR, you'll need a circular (quarter wave) filter, or else those linear polarizers are going to give your some odd results.
5) You don't NEED a bigger version, but it might be nice. I was thinking those softboxes for flash photography might be a great place to start for a nicer, bigger version of this?

And that's it! Hopefully this helps some of you wondering how to make your own scans, and also I hope this leads to even BETTER versions from other people!

If you need any more info, let me know and I'll be glad to help :)

-Bryan K

Last Edit: March 11, 2017, 08:15:55 pm

Hey, that's really cool.   ;D

Question - What's the purpose of the polarizing sheets?  I understand what polarized light is, but *why*?

Other thought - Another way to take "hands off" photos so you don't jostle the camera is to use voice activation on the phone.  If I turn it ON on my Android phone, I can say "Cheese" or "Smile" (and maybe one other word) to take the picture.
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thank you!

the polarizing sheets are to neutralize the specular reflections (which are directional based on light direction), and only show diffuse emission (which is omnidirectional like a glow). This technique is called "cross polarization". Smarter people than me came up with this technique; i'm just borrowing the idea here.

in other words, this device shows true diffuse, and also removes the specular highlights that cause incorrect shape data.

good call on the voice commands 😀

Ah, neat trick with the polarizing sheets.  Thanks for sharing and enlightening me.
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Hi!Really interesting your project.

Sorry but I'm totally new about texture scanning technology...

I think the specular are crucial for realistic materials, but can you explain something more about this point

"1) I'm not getting specular out of this because I'm lazy, but it's not hard to do. Replace that top polarizer with something you can rotate 90 degrees, and then take another set of photos. The difference between the two images is your specular"

It will be really helpful...I wanna try to build my own scanner with a camera based on your project.

Cool! Can't wait to see what you come up with.

Basically, you get specular by rotating the polarizing filter 90 degrees, and then subtracting the result from the original images. Here's a link describing the process. Instead of all that code, you could easily set up a node graph in substance to do the exact same thing.

http://filmicworlds.com/blog/how-to-split-specular-and-diffuse-in-real-images/

I chose not to do that part for the V1 prototype, but it's certainly the very next thing I would add, along with mounting hardware for a tripod/camera.


Hi!

Thank you for your answer....I'm totally new in this texture word But I'm considering to learn Substance. I'm really interested in the Photoscanned materials. I will try to build this device and let you know.Thanks!

This is really neat :]

I thought you need 8 light angle rotations and not 4?  But seems this works well, what's the difference?

you can use 4 or 8.

I actually tried both in an early prototype using a simple set of holes and a light, and chose 4:
-for simplicity
-with a box you can get double the light intensity per side because of the shape
-you can light more evenly, because the strip extends the length of the surface that you are scanning.

With 8, you would likely get more shape accuracy at the cost of what's listed above. Perhaps if you're still shooting the diffuse at full-on and using that result instead of Substance's default way of deriving diffuse, the light attenuation might not matter too much? Not sure. Didn't run those early tests thru Substance to process.
Last Edit: March 20, 2017, 03:49:42 pm