Everything has reflection. Making textures with polarization?

[Vizioen]

I was reading this article here: http://filmicgames.com/archives/547 Where the author has its own homemade setup to apparently take photos with only diffuse values and one with only the specular values.

I remember Grant Warwick posting on his facebook that he was saving up for a camera-setup to do this exact same thing (I think), so he could create his own textures. How would I go on about this. Or how does it even work? I want to be able to do this too, because I have troubles guessing the specular values sometimes and also because I want to shoot my own textures.

Any thoughts?

[vlado]

Sorry, I don't have any advice for you, but I'm very curious what will happen with this

Best regards,
Vlado

[joconnell]

The two things you need are polarizing film to go over whatever light you're using to shoot the textures, and a circular polarizer to go on your camera lens. Rotating the polarizer on the lens will turn it through different directions of light and you'll get either more specular or more diffuse. Ideally you'd have a black room and two lamps left and right of the object you're shooting so you can evenly light the surface of it. The guys in Ikea went pretty hard core with this - they used four lights from up, down, left and right and mounted a camera into the ceiling of their studio pointing down. They shot the texture with each light turned on individually and then blended the four images after to get an even result. They were able to get some really nice normal maps out of the images this way too!

http://udn.epicgames.com/Three/Takin...rTextures.html has a good view of a setup. It's probably not totally perfect but if you've got a specular image and a non spec one, you can probably do something like a difference or a subtract in photoshop to pull one from the other and make it more pronounced.

[Vizioen]

The two things you need are polarizing film to go over whatever light you're using to shoot the textures, and a circular polarizer to go on your camera lens. Rotating the polarizer on the lens will turn it through different directions of light and you'll get either more specular or more diffuse. Ideally you'd have a black room and two lamps left and right of the object you're shooting so you can evenly light the surface of it. The guys in Ikea went pretty hard core with this - they used four lights from up, down, left and right and mounted a camera into the ceiling of their studio pointing down. They shot the texture with each light turned on individually and then blended the four images after to get an even result. They were able to get some really nice normal maps out of the images this way too!

http://udn.epicgames.com/Three/Takin...rTextures.html has a good view of a setup. It's probably not totally perfect but if you've got a specular image and a non spec one, you can probably do something like a difference or a subtract in photoshop to pull one from the other and make it more pronounced.

Thank you for the link joconnell. Very interesting read, I might experiment with this when I have some spare time. Also; I'm an idiot. I found an explanation on the same website: http://filmicgames.com/archives/233 But if some of you have some experience with this I would love to hear it.