What are SubSurfs?


(TheHobbit) #1

I am constantly hearing about SubSurfs, what are they?

Actually if anyone has a link to a Blender dictionary then I’d love to just figure out what all these terms are. I can look anything up in the knowledgebase but thats only if I know the word of what I"m looking for…

Too bad I couldn’t buy a Blender book before NaN went bankrupt :frowning:


(blengine) #2

whoa seriously? hehe…subsurfs are one of the best parts in blender…ok model something(a cube, anything but a sphere)… “darn its not smooth enough” u say out loud… select that object, go into the ediot buttons window, and click on SUBSURF…
aint that cool? it just like smooths your object out but not permanently, u can always turn it off for speed, and turn it on to render =)


(ectizen) #3

SubSurf will turn every face in a mesh into smaller ones, producing a more complex, but smoother mesh. The Subdiv value determines how much to do this.

For example, SubSurf with a Subdiv value of 2 will turn this: http://www.ectopia.net/safi/subsurf0.jpg
into this: http://www.ectopia.net/safi/subsurf2.jpg

The most amazing thing, in my opinion, is the fact that you can turn this on and off at the push of a button, with diiferent subsurf settings on different meshes. That and the fact that you can have this turned on while editing the original mesh, with realtime updating of the subsurfed results! Woohoo! :smiley:


(IamInnocent) #4

It is a mean of making (subdivising) a rough mesh appear smoother/finer by replacing every polygon by roughly [4 at the power of the subsurf used] as many. Neighboring polys are taken into account, much like auto smooth does , so there is no discontinuities. The new polygons arent real, but you can make them so with alt+c.

The big no-no is : no internal point (bad), edge (worse) or face (yikes !).

If you are mathematically incline searchfor subdivision surfaces on Google and come back explain what you’ve understood so I will too.

:wink:


(TheHobbit) #5

Thats cool thanks for helping me out people. I can now use subsurf to smooth out my models! Hurray! I love Blender! :wink:


(pofo) #6

One small tip for modeling with subsurfs.
When making a square (one you really want to be square with subsurfs on) make a circle instead, use 8 or 12 verts (I usually use 12 as it’s easier to make it straight that way). Then rotate the verts that aren’t on the corners until they’re very close (mark four in a square at the same time). Use ctrl if you’re using 12 verts to make sure you get the verts at the same distance from both directions.

  1. pofo

(ZoltarX) #7

Very cool tip. Thanks Pofo!!!

ZoltarX


(K-Rich) #8

… okay… make a cube, and so a subsurf of 2 … looks like a sphere almost… you need sharp edges? select a face (the front 4 vertices for example) and in front view, press Ekey (extrude) and then enter (don’t move them) this will make a hard edge, though it seems beveled… also try it a second time selecting all 8 vertices, this will make a REAL hard edge :slight_smile:

afver you convert to mesh (if you do) you can remove doubles…

K


(Abavagada) #9

This also answered my question about the smoothing, but brings up another [of course].

Some of the objects I have tried applying subserfs to end up “splitting”… looking like they have holes or forgotten faces in them.

I have also noticed something like this when using “Smooth” on vertices. Some areas which you sure were solid suddenly pull apart, leaving that wonderful mesh you created with some now permanent tears.

What is happening and how can I prevent this?


(Vidigiani) #10

Generally that means one of two things:

  1. You have face normals that are reversed. This will give a look like part of the mesh is really dark when smoothed. Uncheck doublesided and any black faces you see need to be reversed

  2. You either do have holes in your mesh or you have overlapping faces. This will just make your mesh look horrible in subserf. Generally if I have this I try to remove edges near the problem area and rebuild the faces manually.

Hope this helps!


(IamInnocent) #11

Tears like those happens when the mesh isn’t made of vertices that are all linked together. You can veryfy if there is more than one ‘network’ of vertices by going into edit mode (TAB), placing the mouse pointer over one vertice and doing LKEY : if any number of vertices remain unselected then you will experience tear out if you use the ‘smooth’ button to the right of the edit button.
If you are lucky and the vertices overlap exactly you may get out of trouble with a WKEY, ‘remove doubles’. Do the LKEY test to see if you succeded.
Of course, the problem is more easily preventable at the time of construction. After, if ‘remove double’ doesn’t help you, you get some big work ahead !


(pofo) #12

If you get black bits when smoothing subsurfs mark all vertices and press ctrl-N to point all normals out. This might not work if you have internal faces.

  1. pofo