Hi pros,
I've started a few months ago with 3ds Max, Mudbox, Substance Painter and I have two basic question which is escorting me all the time.
1. Low / high Poly modelling. As I understood, low/high poly is only needed modeling game props so that the game engine does not need to calculate all the coordinates when the object is far away. In long distance the low poly will be displayed and then near to the camera the high poly will be displayed. Right? Do if I'm not modeling for games, I don't need to model two objects?
2. Triangles. This is also something I learned, that every polygon should be quad, while exporting to a game engine everything will be triangulated. If I'm not modeling for games but architectural stuff or whatever, do I really need to have everything as quad, even if turbosmooth is able to handle everything without artifacts etc.?
Many thanks in advance for your explanations...
KR, Lecra
Replies
2 - yes, the engine will triangulate all geometry but this can also be done manually before map baking to ensure that triangulation doesn't change for the purpose of the normal map bake. If not modeling for games then the topology can be anything you like that suits your purposes. Quads just make life in your pipeline much easier to deal with - sculpting/uv unwrap/rigging.
N-gons (>4 sided faces) are frowned upon generally but are often used depending on the purpose of the mesh purpose/preference of the artist (or client/employer)
Then you make the lowpoly, with an amount of geometry detail to your liking, you'll gradually get a hang of what you can model and what you can skip. You also need to UV this model, no UV coordinates should overlap.
Then you use your application-specific (likely substance) method to steal high-poly's details into textures (which is the main point of baking), these textures will automatically fit the UVs of the lowpoly that you used in the process. You probably want to output Diffuse, Normalmap, Roughness, Metalness, Ambient Occlusion, and maybe Displacement if you figure out how to use it in your game engine.
High poly wont be used in the game itself. What you're asking about is LOD, which stands for Level Of Detail. It is up to the designer to make different meshes for different LODs. This can be worthwhile, but keep in mind that this means creating several lowpoly models for a single highpoly object, and baking them all from the main highpoly.
If you're just working in Max, and Max can tank it, you're fine with just highpoly objects. But sometimes I still bake a proper lowpoly (sometimes in a different scene) and then use that instead. It simplifies things in a long run. Let's say you want to fill an area with rocks using a particle system. Having 1.000 rocks with 100.000 faces each will needlessly take you extra preload time for every render, but 1.000 rocks with 100 faces will preload without you even noticing it, plus the mesh looks simpler and cleaner at a wireframe glance. Additionally, if you're going to copy a model a lot, making a lowpoly will probably leave you with a simple polymesh, instead of that monstrosity of parametric modifier stack in your highpoly. So you dont NEED to make low-polies, but if you feel that it'll take some strain off of you and your computer, it might just be worth it.
As for triangles, dont worry too much about them. They're not that bad. You just want your mesh to be clean. Quads create surfaces that resemble square-grids which look clean to the human mind, but well-placed triangles could very well be a cleaner solution than a quad. You should be able to tell a clean and orderly mesh at a glance, it comes with experience.
As for Ngons, that can be a bit of a trouble. Go to Edit Poly, choose Polygon subobject mode, then scroll down a bit and you'll see buttons called "Turn" and "Retriangulate". Click "Turn". The secret is that everything is triangles internally, even before you export it from Max! Max just keeps them out of sight. You can click the dotted lines to flip their orientation, or you can hit "Retriangulate" to let Max decide the order. Quads only have two trangulation states... but Ngons have many possibilities, most of which will look wrong. So to put some extra control on Ngons you can "Turn" the dotted lines by hand, but you may just as well replace them with actual and visible edges.
As for Turbosmooth, it's quite fine. It outputs the same kind of mesh as without it. But Turbosmooth still doesnt turn Ngons into quads, so you're left at the mercy of the invisible dotted lines, because when you export, each of those invisible lines will become a visible triangle edge.
If you want to triangulate or quad right there in Max, put a "Turn to Poly" modifier above your modelling modifiers and limit the polygon size to 3 or 4, dont worry, it's non-destructive. It has a set of controls that makes the division more predictable, so you can get your mesh how you like it before you get to export it.