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Sculpting vs. Modeling

Started by February 24, 2015 02:01 AM
6 comments, last by riuthamus 9 years, 9 months ago

Hello everyone,

I'm new to 3D Animation and Modeling and I was hoping a more experienced practitioner could help me with some questions I have. I've decided to jump right into learning instead of waiting months until I can start taking my Multimedia classes. I've been testing out various programs, researching, practicing, etc for about a month now, so obviously my knowledge is limited to say the least. What I would like to know is:

1. Is it possible to design characters without modeling?

I've experimented with Maya and found it very intuitive, modeling doesn't seem too complex but its a bit unforgiving. However, I think I could do the exact same thing 100x faster with sculpting.

2. Can sculpted hair be animated?
As I understand it, zbrush is like molding a lump of clay so if I wanted to make hair for a character it would be attached to the sculpture and unmovable? Almost every video I've seen, hair is done in Maya or another program and is animated later. Is there no way to make animateable hair in zbrush?
3. Why aren't high poly models/sculptures used for animation?
I've been seeing this a lot on forums and I was puzzled as to why. I guess people make low poly models, then high poly ones, then low poly ones again for animation?


I don't plan to go into making video games or anything, I would just like to learn so that I can make my own videos. So I guess that would make me a hobbyist? I was planning to make characters, environments, etc and animate them in Source Filmmaker to use for my own personal projects but if I can do this better/faster with zbrush as opposed to modeling I would love to. Thank you to anyone that offers their knowledge and wisdom. biggrin2.gif

1) In big studios, a character's design usually starts with illustration -- a concept artists will paint a whole bunch of pictures of the character. Then a 3d artist will do a high-poly sculpt, then a low-poly mesh will be created, then UV's and textures will be created.

Other times people will make a low-poly mesh first (after the concept/illustration phase), then import it into a sculpting program to add extra details, and then bake those details back onto the low-poly version.

2) You usually convert "sculpted" models (aka rediculously high poly-count models) into low-poly models for use in games... There's no reason that hair is any different. However, realistic hair rendering is a tough problem, so there's often very specialized workflows around making animated hair.

3) Sculpted models are generally too complex for use in games directly. It's a matter of optimization to transfer/bake the high poly details onto a lower-poly mesh. Also the topology of sculpted models is often terrible, and a hand-authored low-poly topology can be animated/deformed better without strange twisting/shearing/bending occurring.

After you've made the low-poly version of the model, you then rig it to a skeleton, and then animate the skeleton. There's no point spending time rigging the high-poly version to the skeleton if it's never going to be used in a game.

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Adding a bit to Hodgman's answer, depending on the game you may actually need to create a character system rather than individual characters. For example, every MMO needs a few base models with a set of all the animations needed for the game, on which the hair, clothing, and weapons be switched out, and the textures switched around, and in many games things sliders can be used to change the relative size of various parts of the body. Many single-player games also use avatar systems - South Park's Stick Of Truth is a recent example of a single-player RPG/adventure game with an extensive 2D avatar system. Single player games which allow the player to capture or breed animals usually have a character system of some kind for the animals too.

I want to help design a "sandpark" MMO. Optional interactive story with quests and deeply characterized NPCs, plus sandbox elements like player-craftable housing and lots of other crafting. If you are starting a design of this type, please PM me. I also love pet-breeding games.

1) If you are interested in a sculpting tool without the need for a modelled base mesh at the start, have a look at 3D Coat, especially the Voxel sculpting part.

Basically the tool works in a way where you can start with primitive objects (like cubes, spheres, but also imported meshes) that get converted to voxels (3D pixels), and then you can work on that without worrying about the topology of the model (because you are working on the voxel model underneath, and that model gets converted to a polygon mesh for diplaying in the viewport automatically).

Voxel Sculpting has its own set of limitations and shortcomings, so its not the silver bullet some people are looking for, though.

Something similar can be achieved, to my knowledge, with ZSpheres in ZBrush (minus the part of not worrying about topology while you sculpt)...

1a) About being faster sculpting than modelling... that depends now on what you do... roughing in a mechanical model in 3D Coat Voxels vs a poly modeller is most probably not faster, maybe even slower. And depending on how much smooth curvy surfaces you have, both will be blown out of the water by a good NURBS / CAD tool... that is why its good to learn to use NURBS tools.

If you are adding highfrequency details to a model, or try to sculpt the musculature of an organic model over its basic structure, you will be hard pressed to do that in a poly modeller in any efficient manner.

That is why both kind of tools are usually used for different phases of creating a model. Poly modelling and NURBS / CAD modelling to create the base model, Sculpting to add the details or refine the basic organic sculpt (that might be just a skeleton at this point in time).

2) About the hair: traditionally hair was added at the end of character modelling, when the finished sculpt was taken back into a poly modeller and hair was added as simple flat meshes that represented a single strand of hair... add 50 of these, scatter them around the head and angle them correctly, assign a nice Hair texture with an alpha channel, and you get nice looking hair that is actually not that hard to create. AND will not look like a plastic wig like what you can achieve with sculpting.

Now, with some of the new systems being developed by Nvidia and AMD, that might change (TressFX Hair system for example)... no idea what the workflow is there.

3) If you are talking about animated movies: actually, there high poly models are used. That is also why it needs to be rendered offline by entiere farms off very powerful computers. For your usual PC, that models would even take long to render if you just rendered out a single frame... at interactive frame rates, that is not possible yet with current hardware. So for games, high poly models are too demanding.

And thanks to bump mapping and other graphical tricks, its also not really needed. There are cheaper ways of making a game model look more detailed than it is, and while you can still spot its low polygon nature sometimes during the game, you will mostly not notice that at all.

If you lack the skills to do the traditional "concept art->base mesh->high poly sculpt" workflow, you can skip right to the sculpt. Personally, I can't really draw my way out of a wet paper bag (to crudely hack the phrase), so I just jump right to sculpting. Using the right tools, sculpting can be a very free-flowing exercise, much like traditional sculpting in clay can be. The character in this screenshot, like all of my characters, was created as a sculpt with no before-hand traditional 2D concept sketching, for example. For someone just starting out, or on a limited budget with a limited traditional art skillset, it can be a workable path.

If you don't want to pay high dollar for ZBrush, Mudbox or 3DCoat, you can pick up the nicely intuitive Sculptris for free from Pixologic (the makers of ZBrush). Additionally, Blender now offers an adaptive subdivision scheme during sculpting, similar to that offered by Sculptris, if not quite so UI-friendly as Sculptris. The adaptive subdivision makes it easy to start from a simple primitive such as a sphere and grab/pull/glob your base shape then iterate, adding detail as you go.

Of course, as previous posters have mentioned, if you want to actually use the sculpted character in something, you're probably going to have to retopo your sculpt to derive a lower resolution version, complete with normal maps and/or displacement maps. High-res sculpts can easily weigh in the millions of vertices, making them unsuitable for animation without expensive high-end cluster hardware.


1. Is it possible to design characters without modeling?
I've experimented with Maya and found it very intuitive, modeling doesn't seem too complex but its a bit unforgiving. However, I think I could do the exact same thing 100x faster with sculpting.

Sure is, but I think your question should be reworded. If the end goal is a 3d character to be used in the game your question makes no sense.


2. Can sculpted hair be animated?
As I understand it, zbrush is like molding a lump of clay so if I wanted to make hair for a character it would be attached to the sculpture and unmovable? Almost every video I've seen, hair is done in Maya or another program and is animated later. Is there no way to make animateable hair in zbrush?

In almost 90% of the cases you would never animation directly from your sculpt. You would need to retopo (all though you can do this at a much higher fidelity) and animate from there. Voxel painting is not meant for todays engines (not yet anyway) and thus the reason why you have to retopo it.


3. Why aren't high poly models/sculptures used for animation?
I've been seeing this a lot on forums and I was puzzled as to why. I guess people make low poly models, then high poly ones, then low poly ones again for animation?

Not sure what you mean by this... the only real reason for high polygon models is for presentation. If you are making a movie or a poster you almost always use the high polygon model. I assume you mean the voxel painted form. Keep in mind that voxel painted (default for zbrush and 3dcoat ) is not th same as a polygon model (used in games and such). For example, dota2 uses high polygon models for the facial animations and UI, while they use the low polygon model for the game itself.

So, high polygon models are used, but not in the way you are thinking.

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1. Is it possible to design characters without modeling?
I've experimented with Maya and found it very intuitive, modeling doesn't seem too complex but its a bit unforgiving. However, I think I could do the exact same thing 100x faster with sculpting.

Sure is, but I think your question should be reworded. If the end goal is a 3d character to be used in the game your question makes no sense.

I think he is talking about "modelling" as "start with a polygon model as a base" versus "dive directly into sculpting".... which makes some small amount of sense if you think about voxel sculpting in 3D Coat or ZSpheres in ZBrush, which technically let you start your sculpt without box modelling a base first.

Hm... well he can certainly start from either. If sculpting is where you are strong start there. You can always retopo later if you need to do anything else with the high poly model.

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