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### 3.2 The forest borders The forest in TerraScene looks a little bit geometrical. We’ll focus on the borders and try to give them a more natural look. The places where some forest and urban areas meet needs some adjustment too; it looks better if we manage some smooth transition. Remember that we work on the shadow map - we don’t draw the modifications directly to the texture map. If you want, you can do it however; I chose this method to limit the number of images simultaneously opened. The only way to modify the textures is to lighten or darken some parts of the shadow map which will later lighten/darken the textures themselves, after the final merging. Keep this in mind when reading the following chapters. If some operation seems unclear to you, look at the chapter 3.5 of this document to see the effect it will have once the shadow and the texture layers will be merged. Open the selection map and select every color which maps the forest zones (be careful : not the clearings). Use the magic wand or SELECTION > COLOR RANGE. NOTE : I added a dark mask to the picture to highlight the selected zones. Save this selection as the “Forest” channel inside a new document. You have now a document named “Untiltled-1”, which will be a “container” for all the work channels to be created.
Select all kind of urban areas. SELECT > MODIFY > EXPAND the selection to give some more room to buildings. Save selection as a new channel (“ExpandedUrban”) to the document you created before (usually Untitled-1).
#### Transition with urban areas Select the new document; take a look at the channels you just created. Now let’s go for some calculation. IMAGE > CALCULATIONS… Ok, do you remember the explanations before? Add the reverse of “ExpandedUrban” to “Forest” channel. Choose “New channel” as a result. Rename the new channel as “Forest2”. The borders of the urban zones have been removed.
#### Jagged borders Select the channel “Forest2”. Click “LOAD CHANNEL AS SELECTION” icon on the channels palette. Expand the selection a bit. The borders of the selection will not follow the roads anymore. It will preserve them from being too jagged. Contract the selection more than you expanded.
Set foreground color to white EDIT > STROKE the outside of the selection. The edge is erased. SELECT > BORDER…
FILTER > DISTORT > DISPLACE… Try the “DMRandomLarge” displacement map I gave before, or create your own. Here it is set to 10%. Add some contrast until the border is sharp.
(Optional) Select the borders again and FILTER > DISTORT > DISPLACE with a smaller and less contrasted displacement map, this time doing the roads too. Some cleaning : APPLY IMAGE, Add “Forest” channel to erase the pixels which were displaced past the limit of the original forest area. The new forest is entirely included inside the limits of the old one.
#### Apply the changes Now we want to apply this new shape, keeping in mind that we can only modify the final picture through the shadow map. We’ll use a little trick : the forest is generally darker than other textures. We have to clip the “Forest2” shape ” from “Forest” channels : the remaining pixels are those that must change their look. We’ll just lighten those pixels and they will loose the forest aspect. Open the “ProjectShadow.tga” document. Convert it to grayscale. IMAGE > CALCULATIONS : add Forest2 to inverted Forest channel, this time, choose “Result > Selection”. Adjust BRIGHTNESS – CONTRAST for selection. Contrast must be high, and brightness slider must bring most parts to white. Be careful to keep the relief shadows dark enough. That’s it! (Also see Part 5 : Advanced) NOTE : We have now virtually adjusted the forest shape, but we’ll not see the result before the final state, when the shadow and texture layers will be merged.
### 3.3 The forest shadow This adjustment will greatly improve the forest’s look with the illusion of relief. We will add some stretched shadows along the forest edge, and for this we’ll use the Displace filter again. To achieve this effect, many ways are possible, feel free to experiment other techniques than displacement maps. If you want to do only a limited number of steps to improve TerraScenery, this chapter and the next one will achieve the best effects. NOTE : Each time we use a displace filter to create some shadows, LOAD THE CHANNEL AS A SELECTION, and then INVERT this selection. Or select the white area with the magic wand. Only then, apply the filter. In case of successive displace filters on the same channel, no need to reload the selection each time. #### Draw the shadows Duplicate the channel “Forest2”. Rename the new one “ForestShadow”. This will be the work layer. LOAD CHANNEL as selection and invert selection. In this way, the black area won’t be messed when applying the filter. The Displace filter uses the pixels at the edge of the selection, and the black edge pixels will be “stretched” like tree shadows. FILTERS > DISTORT > DISPLACE. You may use here the small displacement map given at the beginning of this document. Do only small displacements each time. It avoids jagged shadows near the very small areas. The parameters depend on the position you gave to the sun in the shadow rendering’s options. IMPORTANT NOTE : The “tile” option must be selected. NOTE : As a rule of thumb, with the sun at 220°, I did each single displacement at –2% horizontal and 5% vertical parameters.
Repeat the displacement filter 1 to 4 more times until you are happy with the result. Keep in mind the vertical angle you gave to the sun: in the evening, shadows are longer. (See the “Advanced” part for finer enhancements) IMAGE > APPLY IMAGE : add channel “Forest2” with invert. This removes the forest and keeps the shadows.
#### Apply the shadows Go to the “ProjectShadow” document. SELECT > LOAD SELECTION : choose “Untitled-1” document, load the “ForestShadow” channel. EDIT > FILL with black.
#### Darken and emboss One can observe in reality that any type of forest looks much darker than fields, grass or towns. I suggest to paint it a bit darker. (See also “Advanced” part). NOTE : For this purpose, you may prefer to modify the base TerraScene textures. Finally we’ll add some “emboss” effect to the forest. We do these steps on the “ProjectShadow” document. Create a new layer (“GreyLayer”) over the shadow map. Fill it with neutral grey (brightness=50%). Note : This layer will capture the lightning effects applied on the upper layer. I found this way to eliminate some weird bright spots inside the deep mountain shadows. Create a second new layer (“EmbossLayer”) on top of the others. SELECT > LOAD SELECTION : Forest2 from Untitled-1. Fill with a dark grey (here Brightness=25%). LAYER > EFFECTS > BEVEL AND EMBOSS. Choose the “Emboss” effect. You can play with “Opacity” of shadow and light, or keep the defaults. Use the same angle you entered in TerraScene for the direction of the sun. Merge down this layer with “GreyLayer”. (Blending mode : Normal)
Set blending mode of “GreyLayer” to “Overlay”. MERGE DOWN again. And it’s all done for the forest!