Subdivision Surfaces

Lpear

Hello,

One of my friends recently went to apply for a game company and was shot down because they said he needed to model using subdivision surfaces. We are both at the same university (he just graduated and I have 2 years to go) and our 3D modeling course trained us to model in maya and 3DS max using polygons, and we also had a very brief training in NURBS. After hearing about his interview, I went out on the internet to search for documentation on subdiv surfaces. Everything I found said that subdivision surfaces weren't really plausible for games because it takes such a great amount of cpu for them to process. I've only been modeling for about a year, and a lot of this stuff still goes way over my head. Could anyone possibly explain to me the current presence of sub d's in games and why a game company would say that it was the best way to model? Also, if I were to use them in a game, how would I go about determining a sort of polycount in terms of how many my game could handle. Would it be best to have a balance of both polygons and sub d's?

Thanks for your help!

sprunghunt

Lpear wrote: »

Could anyone possibly explain to me the current presence of sub d's in games and why a game company would say that it was the best way to model? Also, if I were to use them in a game, how would I go about determining a sort of polycount in terms of how many my game could handle. Would it be best to have a balance of both polygons and sub d's?

Thanks for your help!

People do not use sub-d's for the final low poly model.

You need to be able to High poly model in sub-d's. So you can bake normal and AO maps from that.

here's a sub-d highpoly model:


RH_roboTrophy_render051310 by sprunghunt, on Flickr

and here's the lowpoly:

snow

i think you've confused yourself, subdivision surfaces and polygon surfaces are basically the same thing. a subdivided model is just what it says a "subdivided model", it takes any polygon you make and subdivides it, which in result gives you a more dense polygonal mesh - and gets coined a subdivided model. so when they say you can't use it in games, they mean it's because of graphical limitations, however it could actually work in a game environment, as its still pollies. it's not like nurbs, or curves, which are a different thing altogether.

so when the company says you should learn how to create subdivision surfaces, they want you to know how to create subdivision surfaces (high poly models) to bake normal maps for your low poly model, not game ready subdivision meshes.

m4dcow

Well Maya has something called sub division surfaces, and it is a cross between polygons and NURBS. However these days when someone refers to sub division surfaces, they tend to mean smoothing a polygon object.

Michael Knubben

May I ask how much this education costs?

Not to mock you (you seem to have been let down by your teachers), but this is elementary knowledge for an artist these days. I see you have two more years left at this university, so I suggest you post here often and don't rely on your teachers to prepare you for the industry -odds are they've never worked in the industry themselves, or too long ago.

BARDLER

Working is sub-d is extremely important for creating nice crisp and clean high polygon models for detail. In Maya hitting the 3 key is sub-d mode, or some people call it smooth mesh preview, and this allows you to see what your final smoothed model will look at. Once you get all that nice detail into your super high poly model you bake it down to a low poly game ready model.

I have to ask what school are you guys going to that doesn't teach you sub-d modeling?

Lpear

We go to Michigan State. We were taught to use smooth preview while modeling, and to use bump maps and such, but I am not speaking of smooth preview. I'm talking about the separate tab in maya called subdiv surfaces. It has its own tools that you can use to manipulate the surfaces just as NURBS have different tools than Polygons. Is this technically the same as smooth preview? I was under the impression that they were different. Sorry for the confusion, it's just a little bit lost on me, and don't worry about my education guys, I'll be fine :P I have only taken one semester long course that taught me pretty much just the basics of modeling. I have many more courses to take, including courses that are geared more towards modeling for games. I will be sure to stalk these forums too and take all the information from them that I can get, haha.

sprunghunt

Lpear wrote: »

We go to Michigan State. We were taught to use smooth preview while modeling, and to use bump maps and such, but I am not speaking of smooth preview. I'm talking about the separate tab in maya called subdiv surfaces. It has its own tools that you can use to manipulate the surfaces just as NURBS have different tools than Polygons. Is this technically the same as smooth preview?

http://en.wikipedia.org/wiki/Subdivision_surface

any surface that is smoothed and tesselated at the same time is usually referred to as subdivisional surfaces.

what they mean is highpoly modeling that isn't created using zbrush or nurbs.

A proper subdivisional surface allows you to selectively tesselate areas for more detail and harden and soften edges without changing the base mesh - but few people actually use these features.

Lpear

Aaah!! I get it! Thank you very much. Subdiv surfaces do seem to be a good way to do that, since you get so much control over the details. Do you know if employers gernerally prefer you to use subdiv surfaces rather than zbrush? Would you say it's a better way to go about high poly modeling, or do you think it's more of a preferential thing?

sprunghunt

Lpear wrote: »

Aaah!! I get it! Thank you very much. Subdiv surfaces do seem to be a good way to do that, since you get so much control over the details. Do you know if employers gernerally prefer you to use subdiv surfaces rather than zbrush? Would you say it's a better way to go about high poly modeling, or do you think it's more of a preferential thing?

It really depends on what you're modeling. Generally mechanical stuff (like the robot I posted) is quicker to do with subdiv surfaces. But you might want to mix and match techniques.

Definitely learn both subdiv and zbrush if you can.

throttlekitty

Maya's subdivision surfaces aren't very useful, IMO. They tried to bridge Polygons and NURBS, while giving the user the toolset of neither. You can go up/down in resolution and get smooth shapes, but you can do the same in nurbs or polys just as easily.

Danielmn

you know what not to take too much of a crack at cg education,

but its crazy, that I notice as bad as some "TRADE" schools are, the universities can sometimes be far worst.

I think they deal with a lot more theory at times and theri ntry level 3d class / 101 course teaches them so broad because you have people taking that course as an elective sometimes and not as a cg major quite often.

While trade schools move fast at least the teachers know going into the class 90% of those people will stay in the cg major for a while.

while a university has to sometimes teach broad until you take their master courses.

For instance, here in Dallas, SMU Guildhall is a great place to go....if you getting your masters. But i hear the minor course are not enough at all.

Its just really funny I think either way. If I was going to school now I would do gnomon of vfx phd, something more online and subscription base schooling, and community college.
Save money and invest in my hardware

Eric Chadwick

We have some good learning resources here on the wiki
http://wiki.polycount.com/SubdivisionSurfaceModeling