Pros and Cons or Best Practice: Workflow

[noonespecial]

For the purposes of using high poly assets to bake normal maps, what are the advantages and disadvantages of the different workflows?

1. Create Low Poly Model, then make High Poly from Low Poly (Subsurf or other method)?

2. Create High Poly Asset, them make low poly from decimation/retopo?

3. Create the low poly and high poly separately?

Because of my inexperience and lack of a formal education in 3D Modeling, I actually use all three. I find that some models won't subsurf properly, so I create a high poly and decimate/retopo. On a few occasions, I've created a low and high poly separately. Most commonly, I use low poly to high poly via subsurf. Such as, a low poly base with a few hundred tris. Subsurf once, add big details, subsurf again, add medium details, subsurf again, add small details. Then I usually use xNormal to bake normal and AO from the high poly. When these results aren't desirable, sometimes I will do the normal and AO bake in Blender.

[CaptainKipard]

Personally I wouldn't bake normal maps for KSP mods in the first place. IMO baking normal maps is mostly useful for organic models, not machines, where sculpted imperfections are fine. You're better off designing a bump map manually and converting it. It'll give you more control, and you wont have to worry about seams.

[noonespecial]

On some things, I whole heartedly agree with you. But baking from high poly is not without it's uses in KSP or for hard surface models all together.

I'll offer the following as an example. In this one, I made the high poly (right model) first. The engine bell with ridges is a single mesh, and each pipe a single mesh. I then created a low poly from the high poly by manually retopo'ing it, then baked the normals from the high poly onto the low poly in xNormal to create the normal map used in the low poly (left model). It came out rather clean and with less than a quarter of the tris of the original model.

[landeTLS]

I usually do highpoly first.

i Start at lowpoly. add bevel modifier (dont use edgesplit for highpoly. It will leave jagged edges around details when baking normals) Add subsurf (turbosmooth for you maya/max users) and add any detail by floaters and modelling(i highly recommend using floaters for highpolys that are made for baking, even cavities and grooves works well it, looks odd close up but bakes out very well). Make sure your highpoly model is made up of mostly/all quads. Otherwise subsurf/turbosmooth wont work properly(quad > "tri-like-quad" > tri > ngon) you can however squeeze in the odd tri or ngon here or there on flat surfaces if needed.

I then recreate the general shape via snapping for the lowpoly model(note: this is technically retopology) Unwrap the lowpoly and Bake normals and ao from the highpoly.

Real retopology really isnt needed for mechanical modelling. Retopology is more for a different workflow used in organic modelling(Sculpt a detailed model with dynamic topology, then manually create a new mesh ontop with bsurfaces and or the shrinkwrap modifier)

Two other workflows i know some ppl use are:

cage model(make a general shape that you can create both a highpoly and a lowpoly from) requires a some planning. Good if youre working off a drawing/concept art.

Lowpoly to highpoly: what it says, you make your lowpoly first then copy it and create the highpoly from it. Requires more planning that high to low.

Also like cpt. Kipard said. You dont need to create highpoly models for ksp. But it does take the load off your texturing workload as most details will already be established on the ao/nrm. That being said with good texturing you can achieve some really cool artistic effects you just cant achieve simply by baking.

Edited December 15, 2014 by landeTLS