Waverley Abbey - Ash Tree - HistoricVR - Photogrammetry Reconstruction

° Fraxinus excelsior trees can be easily found in the United Kingdom and Ireland. I chose to include this particular model in my portfolio to showcase the possibilities of model reconstruction when photogrammetry capture is limited by natural elements. In this instance, a magnificent English Ivy Vine covered approximately one-third of the tree.

° This model presented not only a new challenge for the geometry reconstruction workflow, (which was exclusively performed in ZBrush) but also for the texturing process. By this point, I had gained significant experience in extracting materials from photogrammetry data. It was time to apply this knowledge to the reconstruction task, where the source data was constrained. In this case, different types and quantities of lichen-covered various parts of the tree, allowing for the creation of material variations.

° The geometry reconstruction process can be divided into the following stages:
-Decimation
-Aggressive smoothing and general shape creation
-Geometry reprojection from other parts of the tree
-Blending seams using morph targets and the history recall brush
A helpful tip: It's worth attempting to create a brush alpha for the morph and recall brushes that mimic the surface of tree bark. This will enhance the transition even further.

° Texture reconstruction relied on a ZBrush-Marmoset-ArtEngine workflow to generate seamless materials. Unfortunately, due to the unstable state of ArtEngine, I was unable to access the project used to create these surfaces. Nonetheless, the general workflow remains the same and involves the following steps:
-Removing gradients to ensure consistency among diffuse, normal, and height maps
-Generating a fake normal map from the albedo and blending it with the baked normal map, (if necessary) to incorporate fine surface details that may be missing
-Achieving seamless texture along the edges and eliminating any unwanted elements (such as remnants of ivy growth on different parts of the tree)
-Performing segmentation to create two additional versions with varying amounts of moss for better blending
-Test renders and export to Substance Painter for model re-texturing

° All other stages followed the standard photogrammetry processing workflow, with the primary objective being asset decimation from the high-quality source model of 30 million polygons down to 1 million polygons, accompanied by a single 8k texture.