I've been modeling in Carrara (since ver. 1 and before that RayDream) for some time now, and am modestly proficient as far as I've been required to be, always trying to get better. Most models have been fairly simple (aerosol cans and caps, store shelves), but some more complex (asymetric plastic spray bottles, metal garden chairs, wicker baskets). I'd like to produce models for the Marketplace and have some concerns and questions - the answers of which would be of use to all of us. I'll be sticking with C6 as that's the program I'm most familiar and comfortable, although I have and have used Hex and Poser sparingly.

I've been modeling in a vacuum and while my models work for me, I've never distributed them. My biggest concern is producing models that can be easily translated to other formats and programs.

What are some of the best safe modeling practices and worst modeling taboos? Any C6 specific modeling protocols or methods that may cause problems in other formats? Any common practices regarding polygon shapes (triangles, rectangles, etc.), polygon counts, number of edges sharing one vertex, etc.? Techniques to use or avoid? Any hideous shader issues from one format or program to the next? Any particularly sticky Poser content issues? What would be the best, most usable format for other programs?

Just makes sense to me to provide the best and most usable model if you're going to put it up for sale or give it away. Thoughts?

 Wow. that's a lot of questions in one go. I'm also still learning to model, but I'll chip in anyway with a few tips I have picked up along the way.

"What are some of the best safe modeling practices and worst modeling taboos?"

Almost everybody approaches modelling problems differently, but in general, quads are good, tri's and n-gons can be problematic. Edge loops (loops of polygons) are your friend. Learn the correct places to put your edge loops and you will be a happy camper. On characters, design the loops to follow the flow of the muscles, so the model will deform and animate well. Start simple, then build complexity. Well placed edge loops will make all the difference.

Some modellers break all these 'rules' and still create fantastic models, but learning the rules will help you know when you can and cannot break them.

"Any C6 specific modeling protocols or methods that may cause problems in other formats?"

If your planning on modelling objects, props, vehicles, buildings or simple charcters then Carrara will be fine. On a personal note though, I have tried many times to create a human model in Carrara 6 pro and I have found it so difficult that I'm not sure if it's possible with Carraras modelling tools alone . By comparison, I bought a copy of Modo and I learnt how to model a reasonable human being in just a couple of days. Carrara is OK, but there are much better dedicated modelling apps out there and it's worthwhile checking out some demo's.

This could be just me, but I'd bear that in mind.

"Any common practices regarding polygon shapes (triangles, rectangles, etc.), polygon counts, number of edges sharing one vertex, etc.? Techniques to use or avoid?"

Quad polygons deform and divide well. Tri and n-gon polygons tend to leave artefacts in the render and don't deform or divide so well. Tri's and n-gons can be used if you place them judiciously on your model (usually tucked away somewhere), but keeping your model in quads will probably give you less headaches.

The downside to quads is that you will undoubtedly get poles (a place where more than four edges meet). You will have to learn to deal with these by placing them on your model in areas where they will not cause any artefacts or problems with deformation.

Squares divide much better than rectangles, especially when used in an application such as ZBrush. If you imagine dividing a rectangle, you will get four rectangles, so you will need to divide a lot more to get detail than you would if you had evenly sized square polygons.

Some people are almost autistic about quads, others are more easy going and some don't let it trouble them at all. The rule being, If it looks good when rendered, divides and deforms well, it's OK. However, keeping your model in quads will most likely do that.

"Any hideous shader issues from one format or program to the next?"

Procedural textures/materials/shaders will be different in every application, so you will have to adjust them accordingly to suit whatever application will be rendering them.

"Any particularly sticky Poser content issues?"

I don't use Poser, so I don't know.

"What would be the best, most usable format for other programs?"

The OBJ format pretty much translates across all worthwhile 3D applications. I'd go with that.

If you want some really good advice, I think you should check out CGTalk

When it comes to modelling (and anything 3D related) the people there really know their stuff. Many of them are professionals who work in the industry.

Good luck, and most of all, have fun!

Thanks Mot, great information. Exactly the type of "rules of thumb" I'm looking for. I've been modeling for years, but in a vacuum, and while in the end the models work for me, not always sure I was doing them "right". Nice to know I've been mostly right.

'Preciate the link to CGTalk as well. Thanks again.

 No problem.

I've also been doing 3D in a vacuume for quite a while, but it's only the last year or so that I have seriously thrown myself into modelling. It's addictive and fun and I've become almost fanatical about it.

It's always cool to meet other vertex junkies.

http://www.subdivisionmodeling.com/page1.htm

This is one of the better Basics learning of the sub-d principles I think.

Brian

I've got a question probably related to this topic. I use the lathe tool a lot, and I noticed that the polyline lathe profile does not remain a permanent part of the lathed object. Once you start editing the lathed object you end up with these leftover vertices and edges. This profile can (and I think should) be removed. It's not so hard to dig it out and remove it with a little work, but is there an easier way?

 Not that I can think of. I think it's just a quirk of the lathe tool,.

You have to double click the newly created object (to select it all) move it, then delete the left over polyline.

Double click to select? Wow, learn somethin' new everyday. It is so much easier removing leftover polyline this way. Thanks.

Hey Benign Lump,

  You have received some good answers here which should get you going in the right direction . With regards to Poser models , I would export the model in OBJ format  which is probably the best format for opening in most 3d programs. 
  When modeling in Carrara don't use "creased" edges to create sharp edges , try and create the sharp edges by using very small bevels instead.  Poser 5 had issues with the smoothing angles but I think later versions of Poser you can specify what angle to crease the edges at so it is not as much of a problem.   So, try and make the model look like you want in Carrara without using creased edges and they should export fine to OBJ. 
  Don't give up on creating characters in Carrara's VM room as I have modeled several realistic characters in the vertex modeler . Good luck .

I'd suggest Wings 3D if Carrara's polygon modeler is a bit too tricky. It's a bit like a poor man's Modo.(With some things Modo probably didn't think of thrown in.) And .obj from that imports fine into Carrara too.

Hey everybody, thanks for all the input. Lots of great tips, links, and information. I'll definitely start implementing some of this advice into my 3D workflow. Now, the problem is finding time to do everything.

Thanks again,
Lump

Too many dimensions, not enough time.

One constant "gotcha" in the Carrara-to-Poser pipeline is surface normals.  For some reason, modeling workflows that include duplicating, or duplicating and welding halves, will cause Poser to decide that certain groups of faces "must" be facing the other way.

There seems no reliable way to straighten out the issue in Carrara itself.  Reversing normals in Carrara doesn't fix the problem for Poser, even if you make sure to detach polygons, et al.  The simplest solution is, oddly enough, to open the mesh in Poser and use Poser's Grouping Tool to find and swap the errant section.  Then re-export the fixed item from Poser.

(Since this is part of my normal flow anyhow; model in Carrara at arbitrary scale, import to Poser using scaling, then scale and position to fit in the Poser universe before exporting the properly sized and fit object, I don't find it onerous to export for a surface normals problem as well.)

To agree with the other posters; Poser will now deal with n-gons, but it renders them badly.  The crease angle set in Poser also does not fix all of Firefly's problems with non-organic shapes.  I have found it nessary to add an additional "constraint" edge loop near some beveled edges in order to keep them from marshmellowing out just enough to make a non-flat surface.  Related to this is the "bagpipe" issue; Firefly smoothing gets a little nutty around cylinders with a length-to-diameter ratio of larger than 1.  They will often bloat out, ending up looking like a python that swallowed a gopher.  A constraining edge loop or two along the length of the cylinder controls this.

For figures and clothing, tris will crunch worse around joints.  Quads are superior.  But when quads get too non-planar Poser will often render surface artifacts.

On the Carrara side, a few more gotcha's; Carrara leaves behind the lathe profile, as stated above.  It also does not always weld the close of a lathed object properly.  It is worth selecting the entire model and hitting "weld" with an extremely low welding tolerance to catch any failed seams.

Carrara will eat groups -- make sure to save group information by, say, changing named polygon groups to materials groups instead.  You can change them back later.

Carrara does not work well at Poser scale, and does not scale and unscale accurately enough to use that as a trick (if you try, say, importing from Poser at scale, expanding 100 times, then reducing 100 times before export, the mesh will shift slightly, usually in the x of the Poser universe).  It seems to make for less headaches to work at a scale Carrara finds comfortable, and fix the scaling and position of the mesh in Poser.

Carrara defaults to spherical mapping when creating vertex objects (the spline objects, however, are created with a decent cylinder map.)  Carrara also defaults to "wrapping" UV's, which wraps them across the edges of the UV space.  This is only appropriate when a single surface uses the entire UVspace: most Poser creations have more complex UV maps with several different shapes sharing a single UV space.  If, however, you uncheck "wrap" UV's, Carrara does not actually unwrap them.  What it does, is invisibly wrap them BEHIND the displayed mesh.  You can discover them by grabbing an edge in the UV mapping room and dragging it.  To properly map a cylinder in the Carrara UV mapping room it is necessary to detach a row of polygons, drag it around manually, then merge it on the other side.  For a complex cylinder this can be a lengthly operation.  Using an external mapping application is probably wiser....especially since UVmapper Pro (Windows only) is so cheap.

All I can think of at the moment here.  At least Carrara doesn't offer the option of double-sided polys, which can cause some strange problems in Poser.