I've been looking at the mesh of established creators to come to some consensus of how dense the mesh should be. I assumed there would be a standard, or a range of sizes depending on how close people would be expected to see the item. Unfortunately I find that meshes are all over the place. I opened a bunch of items in Studio then exported them as .obj files, which where then opened in Blender. The two unmentionable items are very dense with a close-nit mesh. The chairs where, to my mind, not dense enough. I played with Sub-D settings in Studio but am stymied because I thought that selecting increased levels of resolution in the items Parameters panel would show as smoothing in the viewport. I had to select Sub-D in the menu for the item's geometry (see screenshot) before anything happened. The item then looked smoother but there was no corresponding increase in the mesh density. My questions are...

1. Does Sub-D need to be selected in 'Edit'- 'Object' ---- (see screenshot) by the user in order to see results in the viewport AND have the choice in the item's Parameters panel? You can select higher levels of resolution in the Parameters panel but nothing seems to happen in the viewport until after you've selected it in Edit-object-Geometry-Sub-D.

2. Selecting Sub-D doesn't actually add any new geometry, it's just 'faked'(?). If there is new geometry added, it's not displayed in the viewport.?

You can see a perfect example in the two shots of the chair from the 'Reading Room' set. The one displayed as Texture wire shaded shows noticeable hard edges on the front of the seat cushion. After selecting Sub-D via the Edit menu AND selecting a higher display resolution in the chair's Parameters panel, the front of the cushion is much smoother but there's no additional geometry displayed. Oh ya, the one pillow is all triangles. This wouldn't subdivide would it? So triangles are fine IF you have no intention of it being subdivided(?)

Thanks for any insight into this.

You should see the SubD edges as lighter lines in between the base mesh edges.

Why did you bother posting when you didn't answer my questions? You folks at Daz really don't want people to learn this stuff do you?

I did answer - once an item is converted to SubD, and has one or more levels (in viewport or in render) it is using extra polygons to smooth it (assuming the resolution is not set to Base, but then you wouldn't see the smoothed shape). the mystery is why you aren't seeing them, I would suspect it's a video hardware/driver issue.

Only 3 of the viewing modes show the subdivisions. 'Lit Wireframe', 'Wire Shaded' and 'Wire Texture Shaded'. 'Hidden Line' does not show them for me either, you might want to report that as an error or a feature request.

It is interesting how 'Hidden Line' shows the effect of subdivision but not the extra lines.

Its fine,just different views of the topo in different ways. it would be rather redundant for all of those views to show the exact same thing. Maybe you don't want/or need to see all those extra lines from SubD (especially if its a high Res SubD mesh, makes it look dark) and only want to see the original topo. So you can see just what you want, SubD Lit Wireframe view (See thru) the SubD Wire Shaded and the SubD Wire Textured Shaded. that covers all 3 you could possible need to see what the SubD did. And the tris on the pillow You can SubD it but don't know how it will look, or if the shape will keep up, it might be fine, just hit it once with SubD and see.

It's interesting that the best and most enthusiastic help came from the sick and twisted folks in several Poser/Studio adult forums with Perverted-otica being just one of them. I followed many links and read a lot of stuff including tons of background material. This is what I've learned so far....

1. Sub division in Studio enables extra details and allows smoothing of mesh for close ups.
2. An item's (object, figure or clothing) mesh must be built with sub-D in mind if the CC (content creator) wants the end user to be able to use it. It generally means that quads of a fairly consistent size must be used, as other forms of geometry don't always sub divide predictably or properly.
3. There seems to be no standard for initial mesh density (size of individual quadrangles). They have gotten smaller over the years as computers have gotten more powerful. This should mean that there's less of a need for subdivision when rendering, however, there's more of a demand for bigger and more detailed renders so sub division is still used. (this is mostly my observation, ie: opinion.)
4. I'm going to stick with a mesh size of about 1 cm square as this is sorta-kinda what I'm seeing in most meshes from established CC's. Items that are predominantly square/blocky/angled (machines and mechanical stuff) can get away with larger and simpler meshes since sub dividing them is of no use as the item will look the same. If the CC has included surface details, sub-D may still be needed.
5. The end user must first select the item, then enable Sub-D in the 'Edit - Object - Geometry - Convert to Sub-D' dialogue. They can then choose a level of sub division for both the viewport and the final render.
6. The view must be set to "Lit Wireframe', Wire Shaded', or 'Wire Texture Shaded' to see this extra geometry (and the resulting smoothing) in the viewport.
7. The level of sub division selected for the viewport changes the mesh density on the model. If you export the sub divided model as an obj. file, that file will contain the level of sub division selected.
8. The level of sub division selected for use during rendering does not change the mesh density. it's all done internally in the render engine.
9. The smoothing seen when an item is sub divided is done by the sub division algorithm (something to do with cats(?)) used by Studio.
10. You can't sub divide only part of a model, it's all or nothing
11. Triangles may(?) be used on items that will not be subdivided, and need to be draped or D-formed. This type of uneven geometry lends itself to realistic draping or 'squishiness' (the pillow). Quads can look too regular. There is a lot of work and research being done in this area for animation and cloth simulation. I read several PDF's on this that got heavy into math. In a nutshell it seems that irregular sized triangles work best for cloth draping. There's also an irregular arrangement of quads called 'Quadrangular' which has the advantage of lending itself to being sub divided. I'm following these discussions on geometry and topology for dynamic items as it's interesting, and I would like to make some long gowns with extensive veils at some point.

1. While true, as long as you are modelling in an application that has Catmark SubD you should be in a WYSIWYG situation.
2. Size isn't that crucial, it depends on the shape.
3. Not true, as long as the item is saved in DS native format
4. The effect of the SubD is not dependent on that, only seeing the lighter edges from the SubD drawn on the mesh.
5. The render level is sued by Iray, but Iray (as far as I know) receives the divided mesh. 3Delight does its own division, depending on the render settings rather than on the SubD levels.