Smoothing in max

[AtmaWeapon]

A Bit of History:
Smoothing groups are actually something that's been avalible in 3d graphics for many years. It basically assignes polygons to a group so that the renderer knows how to light the object in order to make it look smooth as opposed to faceted surfaces where each face has a specific shade of your diffuse color/map.

Since your question is so vague try this to help you understand.
Make a box and convert it to mesh or poly. I will reference them as the picture attached.

Go to face level and select all the faces and clear the smooth groups. Now none of the faces have smooth groups and is a completed faceted surface.
Select A and B and put them into a smooth group... 1 would be a good start.
Now unselect it, look at it, pan around... notice how A and B appears "smooth" now. The renderer will do its best to make it "look" smooth but since its a hard 90 degree angle, it looks slightly weird.
Now for something a little more advanced - Faces can be in multiple smooth groups to achieve a desired effect. Do step 1 again so that everything is faceted. Now select A and assign it a smoothing group... for this example lets say 1. Select B and make it a different one... say 2. Now select C and select both groups you just used... if your using the examples here then it will be 1 and 2. Now take a look at your box. Notice how the edge between A and B is still an edge but the edge between C and A and the edge between C and B are smooth.
Thats smoothing groups in a nutshell and in case you haven't figured it out, the number doesn't actually matter. Its simply an assignment.

Hope that helps. :thumbsup:

Edit: You are correct. In high poly organic models its usually a good idea to assign everything to one smoothing group. However there are areas that benefit from having different smoothing groups. (finger nails for example).

[MGernot]

...probably hundreds, which is really frusfrating since XSI does it all for you.

Any advice?So XSI knows automatically were you want smooth polys or a hard edge?
Guess, it reads your mind then. ;)

[capone_adam]

So XSI knows automatically were you want smooth polys or a hard edge?
Guess, it reads your mind then. ;) Its just that in xsi theres no such thing as smoothing groups...everything is always smooth.

Thanks Atmaweapon, I think I understand it but still not convinced I could do a entire body with it. I will have a go but I think it will take me ages to work out, will have to write a list of each and every section and its number...such as 'under left eyelid = group 27", 'top of right ear = 31'...its frusfrating because XSI does it for you so its like max adds a extra 3-5 hours on your workload when xsi prooves there is no need for it.

[MGernot]

Its just that in xsi theres no such thing as smoothing groups...everything is always smooth.

Thanks Atmaweapon, I think I understand it but still not convinced I could do a entire body with it. I will have a go but I think it will take me ages to work out, will have to write a list of each and every section and its number...such as 'under left eyelid = group 27", 'top of right ear = 31'...its frusfrating because XSI does it for you so its like max adds a extra 3-5 hours on your workload when xsi prooves there is no need for it.
Sorry, but i really don`t get it. If you modeling a head or any other organic thing,
you will very likely use meshsmooth on top for subdivision (which smoothes everything anyway), so why bother with smoothing groups?

I honestly think your modeling-workflow in Max is wrong.

[capone_adam]

meshsmooth level 2 sorts it out but level 1 doesn't...and level 2 results in too many polys (working on game art)

[Phennim]

I find it hard to believe that with XSI you can create game art with automatic smoothing that is perfect. Can you show us some examples/proof?

[robinb]

One important thing about smoothing groups that hasn't been mentioned. It's only faces that share vertices that need to use different smoothing groups to have sharp edges. So if you want most of a model smooth, assign everything to smoothing group 1 to start with. Then let's say you want the collar of a shirt to have a sharp edge where it joins the rest. Then select the faces that make up the collar, remove them from group 1 and assign them to group 2. Then all those faces will be smoothed, but the join where they match up with the shirt will be sharp. Now let's say the breast pocket also wants sharp edges. You don't need to use group 3, because all the verts are only touching faces that are assigned to group 1. So you can simply use group 2 for those faces again as the faces are nowhere near the collar. It's only when a load of faces that you want to have sharp edges come together at one vertex that you need to mess about with multiple smoothing groups. Usually you only really need to use groups 1 and 2 (maybe up to 6 most). The 32 limit is just for your convenience, as sometimes it can be useful to to select by smoothing groups. Autosmooth uses an angle limit to automatically set up smoothing groups for you, so is usually a good starting point.

Meshsmooth doesn't necessarily apply smoothing, that's an option in the modifier. You can even make meshsmooth keep the seams between each smoothing group on the low poly version if you want to do complicated mechanical surfaces.

I don't know much about XSI, but I bet it has something to define smoothing. Either an angle limit (like autosmooth), or the ability to 'harden or soften edges' like Maya. Or even to edit normals manually.

[AtmaWeapon]

Robin B brings up a very good point. On most of my models I don't use any more than 3 smooth groups. Also, if you are working on game art of an organic model, unless your model is below 3-4 thousand poly's there is (as I see it) no real reason to even use smoothing groups. Granted If you have armor or clothes modeled onto it, then yes you should assign that to a different group. Lips and ears are also a good place to use a different group. But... thats about it.

[EricChadwick]

Not sure if this helps, but here's a tutorial for smoothing groups.
http://www.ghouseproductions.com/tut_headC.html

[capone_adam]

aha, think I am on the right path now...I imagined it meant changing the group number of just about every different area of a character. That tutorial also looks to be have the exact thing I am after...smoothing groups on a head. Now all I need to do is to learn how to model a head properly.

[CGTalk Moderation]

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.