Making the colour map
When you open the baked texture file in photoshop the first thing you might notice is that the top part of the leaf (the one on the right) and the bottom part (one on the left) have the exact same pattern that's because of the nature of procedural textures but to fix this use the heal tool to change the inner pattern on one of the leaves but make sure you don't change outer edges of the leaf because we still want the texture to remain seamless. In this case I find it better to use bigger brushes with their hardness parameter set to 0, that way the healing changes will be more subtle, after you finished healing one side of the leaf rename the layer to "base color".
Now we're going to begin painting some of the details into it but first open the wireframe map that we baked, copy and paste it to our image, position so its right on top of our base color layer and rename the wireframe map to "Wire Reference" and change the blending mode for it too multiply to be able to see it on top of our base color texture, now create a new layer on top of wire reference and rename it to "Leaf Pattern"
To make the leaf pattern you could make a new document and make it so it's about one fifth the size of your canvas, what we're going to do is make a custom brush for the pattern shape. Use the image on the left as a reference for the shape of the costume brush, to make the custom brush just select the entire canvas, then go to edit > define brush.
In the LeafPattern layer, use your new costume brush to paint the patterns on the left side of one of the leaves, then you can simple make a duplicate of the layer and flip it horizontally (image>adjust>flip horizontal) and position it on the right side of the leaf and adjust some of the strokes by lasso selecting them and moving so they come in contact with the edge center vain or you could make another custom brush with a pattern that is flipped horizontally and paint the patterns on the right side, after you finished making the patterns for one of the leaf sides, duplicate the layer and move it to the other side and make regular brush strokes to compensate for the differences in a few areas. Here's a screen of the leaf patterns with the wire reference layer hidden. After you finished positioning the patterns merge all the leaf pattern duplicates into a single layer.
Make a duplicate of the pattern layer and rename it to "pattern soft shadow" and apply a Gaussian blur of about 5, now change the blending mode to soft light, and move it so its a few pixels below the LeafPattern layer.
Change the blending mode of the leafpattern layer to "darken" and change the opacity value of the layer to 25 percent just as a temp color, were going to come back on this and make some changes to this layer later in the tutorial.
Duplicate the "pattern soft shadow" layer and rename to "pattern soft highlight", adjust the hue saturation for that layer, we're going to give this layer a dark green color tone, check colorize and give hue a value of about 115, saturation of 100 and lightness of 10. change the blending mode to hard light and to make the colors more apparent make a duplicate of the soft highlight layer and merge it down (ctrl+e).
Hide the leaf pattern layer and the soft shadow layer, make sure your wire reference is not hidden, now sample the dark green color in the soft highlight layer and paint in the outer edges of the center vain of the leaf, you might want to give your brush a little bit of scattering (in brushes tab) in order to make the brush strokes look a little more random than uniform and change the flow and opacity of the brush to about 50 percent. Use the following image as a reference for painting the dark green areas.
Create a new layer above the pattern soft highlight layer and name it pattern detail, for this were going to make a custom brush to add some detail to the pattern, with this brush it should look like the patterns have this root/lightning pattern on
them. Open the brushes tab in order to customize this brush, enable scattering and give the scatter amount a value of about 95, enable texture and give the scale a value of about 95 and a depth value of 90 in order to give the brush more detail, now pick the texture called "metal landscape" that has the exact effect were looking for, increase the brush size accordingly, also change the opacity value of the brush to about 75 and flow of about 60. Your brush strokes should look something similar to this:
Make sure you increase the size of the brush and the scale of the texture as you get closer to the center of the leaf and decrease it as you get closer to the bottom. To soften and add additional detail to the strokes after you finished going trough all the lines in the leaf pattern, increase the size of the brush and the scale of the texture even more and decrease the brush opacity to 30 percent and give the patterns another pass and that should complete the leaf patterns, now just change the blending mode for the pattern detail layer to overlay and opacity to 75 percent. Use this image as reference for painting the detail strokes.
We're going to go back to the base color layer and add more detail to it, we want the color to be darker in a few areas and lighter in others, we also want to make it look a little sharper since the procedural texture gave us good color tones to work with but not as much detail nor sharpness. We are going to use the dodge and burn tools to make areas darker and lighter and the sponge tool to remove and add color from a few areas as well. Pick the burn tool and change the brush size to about 50, an exposure value of 15, and in the brushes tan enable scattering and give it a value of about 260, enable dual brush and pick number "60" that brush will give us a good level of detail to work with. Start painting, its up to you too decide witch areas of the leaf you want to be dark or lighter, for now just paint the dark areas with the burn tool and when your happy with it make other areas lighter with the dodge tool, make sure the dodge has the same brush size and style parameters as the burn tool's current brush. Try not to paint on the edges.
For the sponge tool we don't really have to use a dual brush, but we will use a little bit of scattering for it but the exact scattering amount is not that important. First set the sponge tool to saturate mode, this will add more color to the painted areas, change to flow to 50 percent, if you look closely at the areas you painted with the dodge tool you will see that some of these areas have almost no color at all, make a pass around these areas to add more color to them. Change the sponge to desaturate mode and decrease the flow to 25 percent, if you take a look at areas we made darker with the burn tool you will notice that some of these areas show a little bit too much color, you might want to give a pass to those areas. Open the burn tool again and make the center root detail a little darker, make sure your not using a brush texture or style and scattering is not really needed since we want to change only the center area and keep it looking rather smooth. Here's a screen with all the changes applied, just a few more details and were finished with the color map!.
Now were going to make a few tweaks and changes to the leaf to improve it even more. If we you take a look at the patterns in a real leaf you will see that the influence of the patterns is stronger in the center and fades away progressively and in the edge of the leaf only a small portion will be noticeable, so what we can do about this is use a soft eraser to erase the areas around the edges of the leaf on the four pattern layers, the reason why we don't merge the four layers into one is because the soft shadow and soft highlight are color only layers, meaning that we don't want this layers to show up in our bump/spec/diffusion/dirt maps so keeping them separated will save us allot of trouble in the future. When erasing the edges of the pattern layers make sure your eraser has a subtle influence such as 25-50 percent to make sure we don't erase them completely and try to keep a smooth progressive transition.
On the base color layer use the dodge tool with a low exposure such as a value of 5 percent to make the center of the vain of the leaf a little brighter.
Our last tweak will be changing the color of your "leafpattern" layer from black to another brighter/brownish tone like the tone present in the center vain, so for now increase the opacity to 100 percent and blending mode to normal, open hue/saturation, check colorize and change the hue value to 30, saturation to 20 and lightness to 20 to give it a dark brown tone to make it look like its coming directly from the center vain, if needed change the values to compensate for the exact color of the center vain of your own leaf. Now change the blending mode to Exclusion and opacity to 75 percent. If you look at the updated image you will notice that the pattern is allot more subtle now, were ready to move on and add the final details to the color map!.
Right now our color map looks really good we could go and apply this map and use a copy of it for the bump channel and the leaf would look really good but we don't want good we want perfection!
Therefore this leaf will have color, bump, specularity, diffusion, dirt, translucence, luminosity and reflection maps but don't worry because things only get faster and easier after we finish the color map!. there is only one thing that is missing with the color map and that thing is damage!, if you look at the 3d surface of the leaf you instantly know that that leaf has been trough quite some damage but the color map suggest that the leaf is almost perfectly healthy. We'll start creating the damage by making a new layer and naming it "damage red", move this layer below the leaf pattern layer, change the foreground color to R:137 G:28 B:74, brush size about 20, opacity of 50, flow of 75, in the brushes tab enable scattering and change the amount to about 250, disable texturing if its checked and use dual brush, use brush number 60. there not really a rule for painting these so just paint the areas that you would like to add this type of damage but make sure you don't paint on the edges ordirectly under the patterns or above the center vain, afterward you might want to burn some of the damaged areas to make some look darker, than others, here's a close-up of the damage so you can see exactly how the damage is shaped using the custom brush and how I used the burn tool to change the color tones.
Now we're going to add are second and last layer of damage, create a new layer and name this layer brown damage, change the foreground color to R:68 G:28 B:9, do the same as you did for the red damage but add less of this type, but this time paint on the parts that are cut away from the leaf such as the area here:
Here's a screen of the completed red and brown damaged areas.
Let's just do a little cleanup before we start with the bump map, create a new set (folder icon) and name that set "Diffuse Color" and drag all the maps to this folder, make sure you keep the order of the layers the way they currently are, but don't add the wire reference to this set, place this layer on the bottom of the set and hide it since we might find a need for it in the future. Control click on the base color layer to select the leaf object, inverse your selection, now with the selection inverted just go over each layer pressing delete just to get rid of some of the areas that we over painted do this to all the layers except the "brown damage" layer, we need this to go a little over the edge because we will render the leaf model using mesh smooth, therefore the cuts will be more rounded off and the extra color in those areas is needed for the texture to blend correctly. Now were finished painting the color map, it's time to move on the making the bump map.
Here's a render of the leaf with the color map applied, don't worry about applying the maps to in max just yet, these are just examples to show the progress of the leaf after each stage.