So I have been doing scans on and off for the last few years starting with the company that has the word pix in the name to photoscan to finally buying the standard licensee of metashape. I have been tasked to do some landscape and higher scans of items on the landscape for an upcoming project where Ill eventually take all this into VR to be viewed.
So I have been messing around with my work flow using some old landscaped data I scanned with my drone (Nadir Images) and wanted to see what you think of how im processing data, what options potentially in metashape I can use and what you find is helpful with cleanup and uv'ing.
Here is a shot of Fly Ranch with the amazing Fly Geyser, which was generated by 318 cameras and produced a model of about 24mil polygons. Notice that the hot springs have holes in them. I realize that the process of photogrammetry has had a hard time with water, trees and other types of vegetation but is their something I can do to help on the initial model creation have these filled in.
I do use the fill holes option which creates some really nasty set of polygons, but is their another way prior to helping Metashape fill these in?
From here I usually try to use gradual selection to find all the floating items and delete them, is this the best way with a mesh so large? Doing manual selection and deleting items takes way to long.
After that I usually do a few things such as make a copy of the model, fill holes, decimate down to 1/2 or 1/3 then smooth the mesh. I can then build the textures by baking from the high poly down, which gets me a model I can usually work with in a 3D program (I use blender). What I dont like is how metashape does its UV's, is their additional tools in MS that can help with this?
From here I make the decision to do the following. Export out the model, run it though the free topology software (Instant Meshes) which further decimates the object and tries to keep a nice topology of quads or tries depending on what you select. Then I take that exported model out into blender and use the sculpt tool (smooth or flatten) to remove bumpy areas, and in this case its all the water. From here I try to build UV's using either Smart UV or just UV and see if it can generate a nice UV layout.
Finally I bring it back into MS and then do a bake to this much more cleaner mesh, or Ill test baking in Blender to see what results are better. From their I repeat the process until I hit a target polygon size depending on where it will be rendered out.
Any other suggestions. I seem to struggle a bit with the UV side of things and have been told to use Zbrush but well I'm not going to pay yet another fee for something that I only use a few times.
Does anyone have any other workflow? I would be curious how you clean your meshes, retopo , optimize and bake?
I did write a small article and do a short videos from a scan I did of a cliff face which turned out ok (dam trees, how can we get better results or remove them easier) See this blog
post . Short
video I guess in a long winded way I'm looking for suggestions on workflows when it comes to large or complex models.
If anyone is interested I may do a 4 part video of my workflow, however I would love to hear some tips on getting better results out of MS ..
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I guess Ill just have to figure out what to do next.
