Snow Effect on Textures
So I was screwing around in Photoshop, working on a texture of mine, when I discovered a cool little technique that you might find useful for when making any material that requires snow or frost in it.
Basically, I started with a nice rock image from CGtextures, then I cropped it to 1024x1024 pixels and made it seamless by manually editing the seams:
You can use this texture for the tutorial.
Once you have your desired texture, we can go ahead and start.
Step 1; duplicate the layer with your texture in it:
Step 2; desaturate the texture in the new layer using CTRL+Shift+U:
Step 3; making sure you're still in your new layer, open the Levels window using CTRL+L, and adjust the arrows until your texture looks something like this.
This is the most important step since the way it looks after adjusting the levels will ultimately determine where the snow will show up on your texture. So you can come back to this step later and tweak it as much as you'd like.
Step 4; Now go to the Select menu and click Color Range:
Step 5; Click on the WHITEST part of your texture in the window, and tick the Invert box:
Step6; hit Ok, and you will notice a bunch of marque lines on your texture, hit the delete key and you should be left with only the white areas, and you should see the original, unmodified texture underneath:
Click on the marquee tool, then click in the gray area around your texture to get rid of all the maquee lines.
You can already see where this is going. The step where we edited the levels has the biggest impact on how this will turn out. Right now it looks like crap, but you will run it through a couple of simple filters to give it a more natural look. Anyways:
Step 7; tired of those hard edges? Go to Filter -> Blur -> Gaussian Blur. The radius can be whatever you desire. I went with a radius of 2. Hit OK:
Step 8 (optional); there's room left for tweaking, obviously. Any pro photoshopper could manually edit the snow for better looks and whatnot, but if you're not that skilled, you can try using the Sponge filter (under Artistic) to give it some more depth. Definition will give the snow more contrast in shading, brush size will vary the amount of shading, and smoothness will determine how icy/crystallized the snow looks.
Not an amazing technique, but it can have good results. Here's a texture I made earlier using it:
I desaturated the entire texture since it's going to be for a stylized scene I'm making.
That's all for now.