Below is the normal map that I produced using the high poly version of my ivy leaf model. I made a couple of adjustments to the image by smoothing/blurring the edges of the leaf to give it a more natural appearance. This is a subtle change but it will show up in the way the lighting affects the finished model.
I've applied the ambient occlusion and normal maps to the low poly/plane version of the leaf model, which gives me a guide as to how the leaves will look so that I can position them before I add the diffuse map. I created a couple of curves (using the EP curve tool) as a guide for the ivy vine and then used the 'snap to curves' tool to position the ivy leaf planes along the vine.
I've made sure to change the scale of the leaves towards the end of the vine to replicate how ivy naturally grows. The spread of the leaves is also important here. The next step was to create a vine model, which I did by extruding a NURBS circle as a tube (in the surfaces > extrude options) resulting in a polygons model. I then tidied model by repositioning the vertices to create a smoother curve. I reduced the polycount here as much as I could, as I know that this vine will be barely visible so it's not an issue for it to be a very basic low poly model.
Next is the diffuse map for the ivy leaves. I used the ambient occlusion map as a guide to work from. I started by positioning the veins (which I took from a photo image I found online), however I then decided that I wanted to create the real details that would be seen from scratch. Using the photo as a guide, I then painted my own veins design on a separate layer and extended these across the whole leaf.
I also painted the base colour of the leaf using a variety of brushes to end up with a painted look rather than aiming for a photo-realistic style. I intend to work this way with all of the textures I create for this project.
