Editing Noise Into Terrain - the Burpwallow Way
Okay here is my long awaited(if not with bated breath) tutorial on the Burpwallow method of noise editing for terrain creation. To start with, I will work entirely in Photoshop. Later I may look into integrating Wilbur into the workflow.
1)Black/White Clouds and lots of Black/White Difference Clouds. This may have lots of islands where you want water and wet places where you want land.
2)Create a Linear Light layer for raising hills and mountains as well as for some lowering.
Layer: Linear Light
3)Create a Pin Light layer for creating flat lowlands. This can also be used to create flat underwater areas.
Layer: Pin Light
4)Create a Multiply layer mostly for lowering areas below water. This can be used in combination with the Linear Light layer to create a less flat sea bottom, but I really didn't do this.
5)Create a Threshold adjustment layer for reference and to create the sea level mask. In my case, I found a threshold of 42(on a range of 0..255) worked well. YMMV. This will be turned on and on frequently during HF editing to allow you to make the shoreline look the way you want it as well as to keep the HF looking good.
6)Using a fairly large soft brush, I painted a fairly bright shade of gray to the Pin Light layer to raise up low areas where I want land. This results in flat, alluvial-looking lowlands. Try experimenting with darker grays to create underwater shelves and the like.
7)Now, on the Multiply layer, I use a darker gray brush(RGB < 128) to paint down areas where I want sea.
--- Because the Multiply blend mode reduces relief(not just heights, but actually difference in height and therefore slopes), this method can be used in combination with Linear Light(basically, add/subtract) to flatten out land areas. Simply use multiply to reduce relief to the desired flatness, and then use Linear Light to raise the area back above the sea. I haven't tried this yet, it might prove superior, in some ways to Pin Light, but it would require closely coordinating work in the Multiply and Linear Light layers to pull off successfully.
8)Some areas on land, I paint hills in on the Linear Light layer. To do this paint in the desired areas with a gray color greater than RGB 128. A level of 128 is effectively zero for Linear Light. Given that, you can also paint in depressions in Linear Light by using a gray darker than 128.
9) Now that we know how the three layers work, we can go back and draw into them, raising, lowering and flattening the terrain until we have something we like. Basically wash rinse and repeat.
10) This is less of a step than an opportunity to give some tips.
First tip, always start out with large fuzzy brushes. You can get really nice effects with some very broad impressionistic strokes, whereas very tight, small strokes can obliterate the noise and leave very visible fingerprints.
Second tip. At the beginning of this project I drew into the layers using a fairly opaque paint brush in Normal mode. As the terrain starts coming together, reduce the opacity of the brush and try other paint modes. I had great success with Linear Light and Multiply to just sort of tweak my existing edits. This is also a good idea if you choose to do some fine editing with small brushes. Still... you should avoid HARD brushes.
Another tip. I didn't do this, but you could use Layer Sets instead of Layers. Then you could be more non destructive by applying edits as layers within the Multiply, Pin Light and Linear Light SETS. Hmmm... Might this way lie madness?
After working with this, you should have a decent terrain to start working with. Next up, makin' it purty!
BTW, I'm posting up a copy of my psd for reference. It's kind of a pig, though, so if folks have trouble uploading it, I might have to put up a reduced res version.
Second Part - Or, "Makin' It Purdy"
As some of you have noticed, the result of our last exercise was a simple grayscale image(yawn). The white areas represent the highest points and the black areas represent the lowest points, elevations in between are represented by all of the intermediate shades of grey. So what you have here is a simple representation of land elevation. With experience,this can be more informative to the eye than hillshading, although sometimes the hillshade holds surprises that even an experienced eye will miss. Sometimes I wish the Lighting Effects filter in PS could work on the fly. Ah well, we have Wilbur for that don't we? But for now let's stick to Photoshop.
As stated previously, this image is purely a representation of elevation, with no sense of climate, or vegetation cover. Later we may cover such issues, but that will be a voyage of discovery for me as well as the dear reader. For now my pretty map will just be a combination of hypsometric and relief shading. Now onto the pretty map.
In my original map, I had all of the terrain editing layers in a Layer Set at the bottom of the Layer stack, but to keep this tutorial simple, let's do our prettification in a separate file. So...
1)First open the original terrain file, turn off the Threshold adjustment layer, Select All, and Copy Merged. This is your heightfield.
2)Create a new file. The size should default to the size of your terrain file, if you have it open. Paste the heightfield into the new file. Give the resulting layer the imaginative name of HF. As an aside, good layer naming will save you a lot of grief and confusion later. It's easier to use good names from the start, than to append them later. A tip I took from every programming book I ever read.
3)Create a new channel, name it HF, and paste the heightfield into that as well. This will be for the hillshade stage later.
4) Go back to the terrain file. Turn the threshold layer back on. Now Select All and Copy Merged. This will be your mask of ocean areas. White areas are land, black areas are water, and there shouldn't be any areas of gray unless you choose to blur or anti-alias the mask. We won't do that here, but feel free to experiment. Be sure to let us know how it comes out.
5)Create another new channel in your new file, name this, "Sea Mask." Paste your sea mask into this layer.
--- So now we have all the data we need from the terrain file, so go ahead and close it if you wish. Especially if your computer is groaning under the strain of your high res image. In my personal opinion, if the computer isn't groaning under a dozen layers or so, you should increase the resolution :) .
6) Now create two Layer Sets name one Land, and name the other sea. These should be above the HF layer.
7) Go into the Channels and select the Sea Mask channel. Load that channel as a selection(there is a button at the bottom of the Channels palette to do this, a dotted circle to the left side.
8) Return to the Layers palette and select the Land layer. Hit the Add Layer Mask button(bottom of the palette, white circle inside gray square, second from left). This will apply the selection as a layer mask for the Land layer set and deselect. Now hit cmd-shift-d(ctrl-shift-d on PCs) to reselect.
9) Hit cmd-shift-i(ctrl-shift-i) to invert the selection, select the Sea layer set and Add Layer Mask.
--- These last two steps assure that water effects will only be applied where there is water and land effects will only be applied where there is land. It also keeps the lower of the two Layer Sets from obscuring the HF from view of the higher of the two layer sets, an important thing.
10)Create a Levels Adjustment Layer inside the Land set. When the Levels window comes up, click on Options... Under Target Colors and Clipping, set both Shadows and Highlights to zero. You could just leave Algorithms alone, like I did, or you could select Enhance Monochromatic Contrast, which might be better.
11)Now create a Gradient Map adjustment layer in Land. When the Gradient Map window comes up, click on the gradient, create a nice dry land gradient that you like. Hit OK a couple times and admire the result. If you set up the sea mask properly, you should see a nicely colorated Land area and some dark dismal gray ocean. That's perfect for this stage. Actually, if you do the hillshade the way I do with a multiply layer, you might want the land a little brighter and more saturated at this point than you'd normally like. Just a tip.
12)Now create a normal layer inside the Land set. Name it... Land Hillshade. Fill it with white, and set the layer to Multiply.
13) Open the Filter>Render>Lighting Effects filter. Set the Light Type to Directional. Set the Texture Channel to HF. I use a fairly intense light with a lot of ambient. Play around a bit with the settings. You should notice after this that the land colors are a bit darker and more subdued and that there are hills! Cool...
14) Create a Levels adjustment layer inside of the Sea layer set. This is pretty much like step 10 above.
15) Create a Gradient Map for the Sea. Choose more watery colors, but otherwise this is equivalent to step 11.
16) Create a normal Multiply layer named Sea Hillshade(blur). Again, not too different from step 12.
17) As in step 13, apply Lighting Effects. Definitely use the same settings for lighting direction. You could play around with a reduced Intensity and Mountainous setting and you could vary the Ambience setting as well to try to make things look a little more... underwater :/ .
18) I decided to blur the underwater hillshade with just a little Gaussian Blur. I don't remember the values, but it was somewhat subtle.
--- Another little tip. Overlay is another good application mode for hillshading. When using Overlay mode, though you will want a rather darker hillshade layer. Instead of white start with a 50%(128RGB) gray, and reduce the Ambience and perhaps Intensity of your lighting effects. The colors of your gradient map will tend to show through much more as you created them and so it can be a little less guess-worky. I tend to choose somewhat bright gradients(read, "freakishly garish."), so the multiply works well for me in a kill-two-birds kinda way. YMMV.
Hopefully, my writing has been clear enough to guide you through the psd file and, in combination give you as good an idea as I have of how to apply, what I think could be a very powerful method.
Attached, find the BurpwallowColorSm psd file. I had to reduce things a bit to fit 'er onto the site. A lot of layers here, folks!
Feel free to ask questions. My time has been somewhat limited lately, so it's understandable if folks have trouble comprehending my bare-bones instructions.
Cheers and all that!