Ok for this tutorial we're going to have a quick look at how to make a worn metal texture in Photoshop. This is going to be fairly quick & easy so it will not be suitable for all purposes. Thing is, no tutorial really ever is. The best ones show you how to go through the process & get an end result, but really only serve as a basis for your own experimentation. To that end please don't email me saying, "It didn't cover how to add mud/sand/blood spots/etc. I'll try to cover as much as I can, but after that it's up to you to experiment and discover new techniques. Ok? Ok.
I also won't be covering all the ins & outs of Photoshop either. If you need to learn the basics, buy a book or look up some online tutorials on using the tools. This tut will expect you to know how to access & use the filters, tools like fill, make selections and know things like when I say 158,174,199 that its an RGB value that equates to a colour & how to get that colour up. Ok? Ok.
Rule 1 of texture creation: Never use the default settings - not on anything, (filters/tools/etc) ever.
For this tut I will be using Adobe's Photoshop, a Wacom Graphire 2 tablet and the 3d Total texture CD, (http://www.3dtotal.com/services/cd/cd.htm) along with a couple of textures from my own personal collection. Don't worry if you don't own the CD or a graphics tablet, you can still follow the tut using a mouse and some workarounds. I'll try to explain some of the workarounds but obviously I can only think of so much & it wouldn't be as much fun if I didn't leave you some room to maneuver.
Sorry I can't include the exact textures I used here. The ones on the 3d Total texture CD are obviously available by buying the CD, so giving them away for free is out of the question. As for the others, I can't remember exactly where I got some of them, which means I can't find out what the rules were regarding redistribution of them. Most were found on texture websites or on occasion a 3d artist's personal site that I visited so its probably not a problem but I'd prefer to play safe here. If you look you WILL find some that you can use. Also magazines like Computer Arts and 3d World regularly have textures on their cover CD's.
First, open Photoshop & create a new file, 512 pixels by 512 pixels, with a white background.
Ok great. Now fill the layer with noise, using these settings:
& now add a motion blur with these settings:
Rule 2 of texturing: Layers are your friend. Use as many as you need. Play with blending modes & transparency - a lot.
Now add a new layer & fill it with 158,174,199. Set the layer blending mode to colour burn & the transparency to 75%.
Next, select the background layer & add an unsharp mask filter with these settings:
Note: Its a very good idea to name your layers. You can change the name of the background layer by double clicking it. I've named my layers 'metal tex' and 'metal colour'. Not very imaginative but I know at a glance what they are.
So now we add another new layer above metal colour. I've named this layer 'paint'. Fill this layer with 10,119,90. If you click on the little arrow on the far right of the colour tab & change to 'HSB sliders' if it isn't set already. Now we'll do a little painting. I used a large round brush (65) & painted some splotches on, using the HSB sliders to change the colours:
I then added a Gaussian blur, with a radius of 5 pixels.
Those splotches are looking too distinct. What I did to remedy that was to use the burn tool (65 brush again) on the light parts and the dodge tool (same again) on the dark parts. NOTE: I never use either of those tools on much more than 15 - 20% exposure as I feel its better to start subtle & build up, rather than have it higher only to find its too much. After that I used the blur tool (100 brush) on the whole thing & just smushed it all around until I was happy.
Ok, add a little noise again, somewhere between 1 & 2. I generally stick to Gaussian, but this time I unticked the monochromatic box. Play with it & see what you prefer.
Rule 3 of texturing: Chaos = real. Randomness including splotches, tonal shifts, noise, water streaks, dents etc all add believability to a texture. Go outside & look at where dirt collects on surfaces & where scratches & wear occur too. Take pictures if you can. You'll also get some sunshine & fresh air to boot!
Here's where it gets a little tough if you don't have the 3d total texture CD. Its time to add some grunge layers. The CD contains a number of grunge maps which are invaluable in creating dirty & worn textures. I'd recommend the texture CD, as it's good value for money & no I don't get commission. You can probably find some on the net for free, (I have)& its a good idea to build up a collection if you can. Failing that, you can create your own, either by taking pictures of dirty surfaces and then altering them in Photoshop by making them monochrome & playing with the levels, or you could paint them as well as using filter effects like noise or horizontal grain for instance, to enhance them. A word of warning - don't just use the clouds filter. It produces random fractals each time yes, but on the whole its easy to spot & doesn't produce great results. If you want to use it, my advice would be to use it in conjunction with other filters like noise or difference clouds, (try running that one about 8 to 10 times for different effects.) or hand painting as well. I generally only use it as a layer to alter the hue or saturation of a colour layer below by using blending modes. It's not just me saying this - Alex Lyndsey from DVgarage.com (an ex-ILM employee) says the same thing. Incidentally DV garage sells a grunge pack too - the surface toolkit, but its fairly expensive for the average artist. They do do some video tutorials that show how things wear & get dirty & what to look for when creating textures for free, which are worth checking out.
I added 2 grunge layers: on which was simply a picture of some concrete I found on the net, the other was a premade grunge texture which I used to add dark random spots to the surface.
Already it looks better. "But what was the point in having the first two layers Mike? We can't even see them!" Well hang on, we're getting to that soon. Ok, so for now, go ahead & add a layer mask to the paint layer, but don't do anything to it just yet.
Rule 4 of texturing: Your object/surface has a history. Think about what it is. What is the object used for? Is it used in the home or in warfare? Is it cleaned regularly? Does it bump against other stuff a lot? Think about how the object is used day to day. This will give you a better idea of where & how to place things like scratches, dirt & dents etc.
Ok, so now go to the channels tab & hit 'create new channel'. It should come up with alpha 1. We'll use this to add some dents. Fill the layer with white (255,255,255) & then make black the foreground colour. (Press 'd' for the default colours) I used a soft round brush (35) at 10% opacity to draw some dent shapes. Once I'd got the rough shape, I used dodge & burn to lighten & darken areas, along with the blur tool and smudge until I was happy. Don't forget that when doing this you're thinking in terms of height - with lighter areas being high & darker areas being lower. You'll see what I mean in a minute if you haven't already guessed. My advice with dents is not to get dent happy. Keep it subtle, depending on your specific needs.
Next thing to do is to go back to the paint layer, (make sure you select the layer & not the mask.) & add a lighting effects filter. Feel free to experiment with different light types, colours & combinations until you are happy. Just remember that sometimes less is more. Remember to drop the menu down where it says texture channel & choose Alpha 1. You should also have ' white is high' checked.
Here's the settings I used.
Now go to edit/fade lighting effects, (or press shift-ctrl-f) & reduce the opacity to about 50%. Leave the blending mode as normal. I had it on darken for a while, but it lost some of the definition due to highlights. I found the other modes changed the hue or contrast too much. Again, experiment to your own taste.
Now select the mask & with a fairly small soft brush, (17) on about 10% opacity, paint around the edges of the dents and also in the middle of them a little. Use the blur & smudge tools if you go overboard. What you're doing is making it look like the paint has got scratched off & worn where the dent is. Now with a very small brush on about 50% opacity, build up some scratches around the dented areas. Also add some faint random scratches elsewhere on the texture too. Another trick here if you find you've gone scratch crazy is to duplicate the paint layer. I kept it on normal blending mode at 100% opacity, but as always play around to see if you like anything else.
This is where having a pressure sensitive tablet pays dividends. Using the same brush & settings, but different amounts of pressure, you can add lighter or deeper scratches. Lots of little scratches close together make nice scuff marks too.
Now to add some chips and cracks in the paint. Obviously there are any number of ways to do this, but this is my method. Its important that you read this bit carefully first before you do it. If you are unsure, copy the 2 paint layers & hide the originals by clicking on the eye next to the thumbnails in the layers tab. Now work on the copies. If all goes well, delete the originals. If not, delete the copies & start over.
Open up a decent grunge map & drag it into your texture as a new layer. Use free transform to resize it to fit if necessary. Now, using the magic wand with a fairly low tolerance, (I used 5) select a part of the texture according to brightness. Usually I go for whichever has less, black or white. Don't worry about shades of grey so much, just pick the lightest or darkest colour you can see. Now go to select/similar. You should have all of the black or white area on the grunge layer selected. Now hide the grunge map layer. Without altering the selection, click on the lower paint layer's mask. Using a large brush on about 50% opacity, paint over the selection (basically the whole texture,) with black. If you've done this right, you should see areas of the metal showing through. The black simply adds to the masked area of the paint layer, allowing the layer(s) below to show. Now repeat the process on the second paint layer's mask with a different grunge map. If you only have one, then use transform under the edit menu to flip the layer. Vertically, horizontally or both - it's up to you. You could also add rotation or whatever you like, just make sure you get a variation on the original. Now I used the same selection again on the lower paint layer's mask again, without flipping or anything, just to make those spots really show through on both layers. If all went well, you should have something like this:
Of course you may need bigger chips or finer detail - just size your grunge maps accordingly using the free transform tool. You don't even have to use the whole map. Size it up so you can only see a small part or add & subtract to & from the selection. You get the idea. Once you are happy you can delete the grunge layers if you want, as you won't be using them anyway. You can also add to the masks by using a speckled brush. I added a drop shadow effect to the top paint layer at about 20% opacity.
Lastly we'll add some rust. This could also be mud, sand (used in conjunction with the noise filter) or blood spots - whatever. When thinking about rust in particular, remember that rust is generally caused by water damage. This means that usually where you find rust, you will also find rusty streaks down the object where the water has gone. Rust also attacks exposed areas, so it is more likely to occur on scratches & dents etc, than areas where the paint is still intact. Create a new layer & set the foreground colour to 100,50,20. Now paint in areas of rust colour on the new layer, keeping opacity low.Just go for broad strokes at the moment. I used the smudge tool to create streaks& then added a Guassian blur, 5 pixel radius. I then used the dodge & burn tools on 10% exposure to highlight & shadow certain areas. Next I duplicated the rust layer and painted in some sharper streaks using a 17 brush, also using the smudge & blur tools sparingly where I thought it was necessary. Normally I would spend a little longer on making the rust streaks look better, but it's very late, I'm tired & you get the idea. Anyway, the top rust layer was set to hard light at 80% opacity & the bottom one was set to darken at 35%. Obviously you'll want to play with these values to suit your needs.
Also by changing the blending modes on the rust layers, you can achieve different effects. Multiply gives you mud, screen is sand & colour burn gives you oil. I'd usually add some noise or other effects to these, like plastic wrap to the oil & maybe mud to give specular highlights. (Actually I just tried this & it didn't work, but you could paint then in by hand using a soft brush & white. As before, broad strokes with some blur & then add tighter highlights on top.) I did add some noise to the sand layers though, making sure to ctrl click the layer to select only the painted areas.