Furniture & Working with Subdivision
Table of Contents
Description
In this TikTok series of short videos (portrait/vertical format) we take a look at how the Subdivision Surface modifier can be used to create a high resolution (high poly) mesh of a single-seat couch, a relative simple furniture item for IMVU, that can then be utilised to bake textures to a low resolution (low poly) version of the item itself; a normal map, and perhaps a diffuse and/or ambient occlusion maps for use in texturing the game mesh. Along the way we’ll look at some hints, tips and techniques for using subdivision in Blender, aiming for functionality rather than fidelity or accuracy.
Duration: total c. 4 hr (04:00:00).
Info: 1080p (vertical format).
Suitability: Beginner+.
Source: n/a.
Product ID: n/a.
Design note: some additional considerations to keep in mind working with Subdivision;
Effective vs. Efficient
When doing using Subdivision Surface as part of the work flow that ends up with a ‘game mesh’, preference should be to initially look at being ‘effective‘ rather than ‘efficient‘ for the high-poly object, so corners can be cut, to a degree, so long as the end result generates a functional low resolution mesh and baked texture set. In other words, where details and features might not be immediately visible to the end user (usage case), they can be fudged or wrangled to get the shapes needed instead of necessarily structurally accurate.
It’s often better to approach projects by being ‘effective’ not necessarily ‘efficient’. While there might be a correlation between the two, but not always – the edge fan is an effective way to remove faces while maintaining general structure.Process vs. Problem Solving
A similar concern is focusing on how something is done rather than why it might be. For example, once a set of faces have been deleted (X or Delete) there are a number of ways the opening can then be closed; Fill – F or Vertex » New Edge/Face from Vertices, Grid Fill – Face » Grid Fill, Bridge – Edge » Bridge Edge Loop or others. Each operation generates a new face depending on the selection and how complete that is, in other words, Bridge only works well is the gap to be filled is contiguous and doesn’t include any odd edges that don’t have corresponding ‘partner’ or ‘edge pair’ the gap to be closed across.
Using Bridge to fill an opening around an edge-loop – in this content it won’t work properly due to the presence of an ‘odd’ edge that doesn’t have a corresponding ‘partner’ edge.Cage, Subdivision & Game Meshes
Generally speaking working with subdivision requires a ‘cage’, a relatively low resolution version of the final object that’s edited to control how the mesh changes as the subdivision resolution increases. Typically this means broader structures are simplistic or lack detail that might then be augmented to have tight loop-cuts placed to define ‘sharp’ edges – Mark Sharp should not be used in this context. If textures are to be baked, the high-resolution can be used to render images relative to a cleaned ‘game’ mesh that’s optimised for use in-game.
The different versions of the same mesh – cage (image-left) is low on detail, includes basic shape/form; subdivided (image-centre) is high resolution, shape being formed by mesh density distribution; game (image-right) is the final form reduced and optimised for use.UV Editing
In full screen the UV editor allows access to Material Properties and other application wide settings and options. Being available, materials can be used to make mesh selections, which in turn highlights the corresponding UVs, individual faces or groups by way of an alternative to selecting UVs; this approach is useful where the same image or material might be assigned to one or more sections of a mesh, the entire grouping being selectable.
The UV Editor layout provides all the tools necessary for editing and modifying the UVs of a mesh.Make Real/Inverted Faces
After using Apply on the Mirror modifier it’s often useful to double check the mesh to ensure surfaces are all orientated the same way, pointing outwards. A quick check for this is to use Face Orientation check faces are not inverted. If they are, which display red, invert or revert them using Normals » Flip from the Mesh menu while in Edit Mode – Mesh » Normals » Flip.
After using Apply on a mirrored mesh, double-check Face Orientation to ensure the mesh, or parts, are not inverted or inside-out.Materials
When bakes are performed the process renders to the active Image Texture node within a single material. If an object has several materials assigned this can result in either an incomplete render or incomplete assignment, i.e. the rendered image only appears within the selected material, omitted from others that might be available. Depending on the object, and how materials are being used, this might then mean ‘optimising’ materials, removing unused instances and consolidating the object to use just a single material instance.
Aside: there isn’t a ‘fix’ for this in the sense that Bake automatically assigns the render to a number of materials, unless they all reference the same image, which is updated, as it doesn’t know which material should be using the render.
If an object only has one image (or set of) being used, it’s best to consolidate if multiple materials are assigned to simplify the process and make project management easier.
Timestamps
Times are approximate;
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