I’ve only updated once this month so I thought it might be a good idea to quickly throw something together. This is my current approach to creating foliage alpha planes.
I begin by modelling leaves which will be repeated across the branch. I prefer to actually model my geometry for my textures rather than relying on photographs alone as this approach tends to generate superior normal maps. For each leaf type I take photographs of two or three different leaf variations to ensure the final product doesn’t look too repetitive. A special technique involving polarisation filters and the DSLR’s flash is used to capture non-directional diffuse light from the leaf surface.
The next step is to model the actual branches and then apply the leaf geometry. Originally I had planned to use ZBrush’s micromesh feature to apply the leaves but ultimately 3DS Max’s Paint Objects tool proved more appropriate. I made quite a few branch variations in this case for experimental reasons; the final texture sheet will not include them all.
This is a preview of the preliminary result in Marmoset Toolbag. There is no lighting information baked into the texture; all visible directional light derives from the normal map.
I am creating two types of pine tree for this project: close-proximity, high-resolution trees, and far-proximity, low resolution trees. Here are the ZBrush sculpts for the high-resolution trees. The human reference model is slightly larger than it should be.