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Thanks TangoAlpha for the helpful explanation.
Thanks TangoAlph, I'll give both a try and will likely mostly stay away from quick fillet.
Thanks Diomede, I was thinking that it would be shown on a YouTube video.
I tried yed another method, unsucessful as it would take a bit of effort. I selected a corners/side edge and used move and scale on that particular edge... result: a lot of fine tuning and welding.... cleanup time which I didn't even bother to try even though it did produce a bevel... purposely didn't even bother to save.
Great.... I used Fillet with default setting for the bottom, tan, edges and sides and then another for the top, blue, top edges. Got carried away in assigning Material Zones for each side, top, bottom and the beveled edges...just for practice. :)
Now that I know what to do I'll start playing around after Carrara Challenge #26: “Caustics and Nautical” is over or perhaps during when I just gotta have a break.
[additional notes] This was my first go at Fillet and some adjusting vertices then welding needs to be to a lot of places.
I like a lot your work MDO, very impressive !
And DesertDude learned me some good tips about the use of deformers on Carrarators, I thank him again !
A few days ago, I've begun to upload some little things on ShareCG, feel free to use want you want : http://www.sharecg.com/DUDU_car
How not to model... like me of course. The first pic, last version, has only single vertices at each point... I've highlighted in red the approximate places that I want windows... the rectangular/square ones will have tops to match the doorway. The round window will likely not be used on this wall.. perhaps a side or opposing wall. I did discover a few things.. If the filled poly is emptied then it will look like the 2nd pic when re-filled... also creating double vertices.... And before filling the entire template/n-gon before extrusion I tried to link vertices which did not work until after I filled the entire thing.
Seems I've fallen down the Rabbit Hole, 2nd pic... which shows what happens when a filled template is emptied and then filled again. 3rd pic... I seem to have met the Mad Hatter which happened after selecting all vertices and welding at custom .10 ft. Seems that I've gotten rid of the n-gons and a few others witch I had thought to be 4 sided polys. I suspect they have disappeared since their vertices/points were not connected to anything and properly. Luckily I have previous versions to fall back on and did not save this result.
I'm bound and determined to make it work.
It may be easier if you start out with a basic rectangle,. and then extract edges where you need to create openings for doors or windows,.
Pic1 .. shows a quick, mock-up of a rectangle, with some extracted edged to create the basic geometry. ..this also keeps things square and clean.
Once you have the "basic" geometry,. you can select and delete poly's, to create the doors and windows,.see Pic2.
You can refine the basic geometry by extracing more edges. and adjust the position of some edges or vertices to create more rounded shapes,. see pic 3
You can also select the edges from the openings,. and duplicate those to create more detailed Window frames or door-frames. and the Windows or doors.
selective edge creasing, and smoothing,. will help to hide your original wall edges.
while extracting edges to model this way, ..you can easily create unwanted polygons,.(normally not an issue) but if size is an issue, you can reduce the polygons by using dissolve to condence one group of polys into a single poly or ngon.
3DAGE, you are absolutely correct of course. Thanks for the examples... wow that was fast... you are AUs ahead of me. I'll scratch my original and start over a more basic way.
Regarding selecting edges and creating more detailed window frames I'm thinking that I should do this after extrusion since I want the outer wall to have a different appearance than the inner wall.
If I end up with an ngon I'll need to repair that to be either 3 or 4 sided polys... correct? Don't know why I'm even asking since it's obvious that I will need to. Thanks once again.
No problem :)
There's no need to make both sides of the wall as a connected model,.EG:(a box)
It' can be easier to deal with as Inside /outside,. you can add different shaders, or adjust the geometry more easily.
It also depends on what the final use of the model will be,. if it's an exterior shot of a house, or street,. then you don't need an interior,. and vice versa.
If it's a fly through of building showing each room, then yes,. you'd see both sides of the wall,. but they don't need to be connected to each other,. just positioned together.
you can Duplicate a single sided wall ,. and move it back, to create the other side,. or duplicale with symmetry,. just check the "normals direction" of the walls,. to make sure that the correct sides are pointing out,. see pic.
Ideally yes,. ..and if it's going to be used in other programs,. it's best to keep things all quad's or tri's
Carrara deals with ngons better than a lot of other programs,. so,. if you're working in carrara you can get away with being a little experimental, buy it will highlight issues with geometry if you go to extremes,. usually something like the strange edge flaps across curves you saw with your first Archway.
but it's important to be creative and experiment,. without worrying about whether what you're doing is right or wrong,. so don't look at those issues with too much importance right now.
enjoy the process of learning by making some stuff, and finding out how the tools work.
it's also good to load up some models (Props, Buildings, clothing )etc.. and look at how they're constructed.
I tried adding a rectangle and then adding vertical and horizontal lines in a few places. I had "snap to grid" on and still had a problem in a few places. :(
Instead I added a rectangular cube and deleted all but one division in-between what was to become inner/outer walls... see pic 1 for a modified result. I took the only division left and moved then welded it to the outer wall. After that I emptied the polygons between the inner and outer walls.
An inner and/or outer is fine when only used on either. What I'm creating I want both and if I do only want one inside or outside for a project I can always save one version of either. Later the camera can fool the viewer by showing a figure walking from inside to outside then cut to the outside wall showing the figure right after they walked out... camera magic. :)
I'd forgotten about doorways as well as huge arches/openings into other rooms or add them on. As far as walls etc needing to be connected they needed to be in my much older... pre Eovia/DAZ Carrara modeler to produce good results. Seems while I'm learning I'm also unlearning. :)
I believe that a YouTube video mentioned that they preferred to have walls with thickness and not just a single side or unusual results might occur... can't remember if they said what or why. Could have been for an older version of Carrara, or even DS.
Now I realize why you showed the pick of the duplicated wall with normals facing correctly. Luckily anyone can select a polygon and use "Reverse Polygons Normals" which I had to do after taking a closer look at pic 4. I must admit that I've never used "Duplicate With Symmetry" before... will have to try it out out just to see how it works.
Ohh.... my other pics... the 2nd and 3rd are views of intermediate steps... the last explains what I'm doing and shows the normals also. Excuse the unusual thickness of the long outer wall... I moved it back in order to select vertices/edges easily... it will be moved back before I'm done.
Everyone should experiment... can't learn without playing with all the gadgets/tool.
Don't forget that door frames and window frames can be separate models too(and if they're slightly oversize, that'll hide any minor irregularities in the wall as well). You'll also want the door to be its own vertex object if you want to be able to open it.
Good points TangoAlpha :)
In the wall example,. i've duplicated the edged from the Window's and doorway,. and used these to create the surrounding frames,. and the windows/doors,.
the surround frames were made using Sweep path,. and a little polyline shape,. the door is extruded after selecting and duplicating the 3 edges from the wall,. and using the link tool to create the 4th edge at the bottom which also fills the poly,. then I extruded that to crerate the door.
all of these are seperate polymeshes, all named,. and with shading domains and uv mapping applied to them.
All of the surrounding frames for the windows and door are larger than the openings, so that they cover the underlying geometry,.
As tango alpha mentions,. the door (and anything else you want to anmate) needs to be Copy/Pasted into a new vertex model,. so that you can place it / group it, in position with the wall,. and add constraints and limits to make it open/close.
I'm not sure why you're having problems extracting edges with the rectangle,. perhaps it's a double click thing,. .. once you create the basic rectangle shape with four edges,. then the first "extract along" should be,..
Select an edge,. go to Model / Extract along, ,. then click and drag from that selected edge, to extract out a new edge.
that edge can be moved or positioned using the front view,. or use Model / Move edge along,.
That new edge can be selected and then you'd use Model / Extract along ,. or Model / Extract Around,. to create more edges which you can move into position.
Once you've extracted some vertical and horizontal lines,. you'll need to use either a double click, or select and "Loop" to select the complete edge, rather than a partial edge.
You can also use the other views,. (top front,..etc) to help you select the edges by using the rectangle select,. depends what's easiest for you
Also,. rather than "emptying" the polygons why not select and delete those,. if you don't need the sides,top and bottom edges between the wall panels,. these gaps would be filled or Hidden by the door frame / window frames etc,.
Snap to grid can be useful,. but it can also be a PITA since it doesn't really snap to the "visible grid lines",. it uses a snap to grid "unit of measurement"
so if you have an edge at 0.3,. and extract using snap to grid,. then the next edge would extract to 1.3,. irrespective of the visible grid.
You can select any vertex / edge or any other part of a model and use the Move tool (right hand panel options) to type in the exact position for X Y Z,. at any point.
so everything is adjustable at any point,.
Also,.when Snap is enabled,. moving things can be more jerky, since it;'s snapping to the grid units.
when Snap is off,. extracting or moving things should feel more fluid,. (easier to use) and you can use the Move XYZ numeric inputs to type in the final position you need.
Hope that makes sense :)
Thanks for pointing these out... very good advice.
Glad you mentioned door/window frames as separate models. I do wonder why they couldn't be separate polymesh of the same vertex object... hmm. It would help if the door/window frames were intended to be interchangeable with others for an entirely different design look... now that does make sense.
Any moveable part door/window or a window with frame it should be a separate object otherwise if opened/rotated the entire wall/room the entire vertex object would also rotate, not just the the door/window/etc. I do wonder why any separate object door, anything moveable etc as it's own polymesh along side of the entire design for a wall etc and later all but the door/frame etc couldn't be deleted and saved out as a different vertex object. Unmovable door(s) etc I'd have to call faux door(s) etc... please excuse me while I try to control my laughter... I'm thinking of cartoon characters drawing a door or opening on a wall.... ha ha... OK I've got myself under control now... I think. :)
I repeated nearly all of your examples with very good results, leaving out the ones I think I'll know how to do, from your advice and pics from my original problem. Thanks again.
BTW: Awhile back, using Carrara 6, as a challenge to myself I created a door and all it's parts... hinges/pins/screws, knobs/lock button, window, and all other hardware, all moveable for a short animation for a web page I made for a client who sells/repairs doors and related parts. I was very happy with the result but it was rather simple and either most or all was made using the Assemble Room. I'm planning on remaking the entire thing a lot easier in the Vertex Room which I'm more familiar with now and a have more powerful tools to work with.
Sure they can be a separate mesh in the same vertex object. But if your window is particularly ornate/complex and gets reused a number of times, it may be more memory efficient to make it a separate vertex object.
Don't forget, when setting up your door in it's own vertex object, to centre it on the barrel of the hinge. 0, 0, 0 in the vertex room will be used as the pivot point (if you don't have a hinge, use the inside corner of the door)
Nearly all make sense. :)
Now I know or think I do know that duplicate, CTRL+D, creates a separate polymesh/poly or only vertices in my last example. pic 2 and pic 3 which are used for pic 4.
Thanks to Cripeman's video on making a barrel, "Modeling a barrel using the lathe tool.", I know how to create shading domains... something that had eluded me before. Tell me... UV mapping is only necessary if using 2D maps for shaders/textures and is not always necessary. I understand that Carrara can use them but they would be necessary for other 3D programs as well as DAZ Studio. Right?
Is there any reason why not to save the original vertex object to a different filename and use it as a reference to create the doors, windows and any moveable objects one at a time to different filenames? What I would do is to save each all door frames, all window frames to their own file names... door 1, door 2, window big 1, window sm 2 etc, to their own files without the rest of the main vertex object.
Apparently either I or Carrara needs a restart tonight. :)
The first pic, a composite, shows what menu item I chose along with how I selected the poly lines... I've also tried selecting the polygon itself with the same result as selecting either 1 or 4 edges to "extract along". The second pic is after moving the selected lines. Note that once I use "extract along" there is no move tool highlighted any longer... I've also tried the up down arrow keys with no effect but did not try +- keys. I did unknowingly get it to work *once"... picture the 2nd pic with the "extracted along" part hidden underneath... when I went back to directors camera I found and selected it then moved it in Y+ axis so that the pic looked like a chimney added to the top of pic2. Sadly I couldn't repeat it again and don't know exactly when/how I got it right. Oh woe is me.
On the cube I deleted the bottom and might have been better off to hide it instead... better yet create a subdivided plane and try with one of the polys or polylines in the middle. I did start off by turning off Snap to Grid right away... before trying anything.
3DAGE said,
Also,. rather than "emptying" the polygons why not select and delete those,. if you don't need the sides,top and bottom edges between the wall panels,. these gaps would be filled or Hidden by the door frame / window frames etc,.
At this point I'm just making all the walls to room measurements I want. Later when I start cutting/punching out the windows/doors I don't mind if there are hidden gaps underneath any frames etc. The room at this stage is actually just me fooling around and finding what might be needed/not needed in a different approach as well as what I did right/wrong. Two things completely missing are a floor and ceiling... just checked and neglected to hide them. Eventually I'll want to make separate objects for the room to cover the top and bottom of all walls and of course a roof... just in case I want to use it in an animation for a tornado scene... showing the entire house spinning up into and whirling around in the tornado. One other stationary part I've thought about are window sills which will be extruded to set objects on.
Snap to Grid needs an overhaul... it works nothing like a DTP or Vector drawing program.
D3AGE said,
Hope that makes sense :)
All except extract along... oh well perhaps it will work fine later today or tomorrow.
Using just a single plane without thickness for a wall (as long as you won't ever be seeing the edge of it) is pretty standard from what I've seen, but in that video they might have been referring to the fact that sometimes you get a little light leak with a plane and adding thickness to it will fix that. Of course, so will adjusting the light/render settings and that's usually less resource intensive.
You also generally want a little real thickness on windows and glass because refraction on objects like that doesn't really work right without it.
In Carrara you really don't even need the object to be UV mapped to use texture images as long as your object is planned out with the projection methods available in Carrara's shaders in mind. If you look at the attached image I have a simple vertex object that I have not UV mapped, but because it is fairly simple I was able to neatly apply an image texture to it using projection mapping in the shader. Even some more complex objects can have image based textures applied to them this way with a little planning, although sometimes the shader tree can get so complex that it would be easier to just UV map the object.
You will need the object to be UV mapped if you want to precisely apply image textures to much more complex shapes though and most other programs will require that an object has a UV map. DS does have the ability to project shaders as well by playing around with the various shader bricks (and there are a few 3DL shaders for sale in the store that take advantage of this such as these http://www.daz3d.com/shades-of-life-bark-booster by DimensionTheory that use camera projection to apply image based textures) but I think the object still needs to have at least some sort of UV map for it to work (I could be wrong about that though).
TL;DR - Yes, you are correct.
Thanks MD2010,
In order to avoid light leakage I now wonder why the botttom/top wasn't simply either extruded or just sunk into the object where it was leaking from. Hmmm.
I've also watched a lot of PhilW's videos where he has added a map on top of a Carrara shader.
I think it is not so much an issue of light leaking around something as through it. Sometimes when something has no thickness the renderer may have trouble calculating every bounce correctly and light may show up where it shouldn't be possible for it to be. It really doesn't happen very often but if you search back through all the old forum threads there are a couple where it happened and people were trying to figure out why.
It's kind of like in a physics sim if the mesh is not dense enough sometimes one object will pass right through another even though they should reasonably collide. But with light.
On UV's ,.
whenever you create a 3d object,. Carrara does two things to it.
It adds a default shader (Texture0) .
it adds a default UV projection method.
both of these things are essential to allow you to colour, or add either procedural or image based textures.
Carrara isn't smart enough to know what type of mapping the object should have ,. based on it's shape ,. so that's really up to you,. but there's always some type of basic UV 's applied to every object.
The UV options in the vertex modeller,. allow you to simply select a "preset" method of projection,. such as Box, Spherical, Cylindrical,. and apply that to the object.
on simple shapes,. those presets are generally all you need. ..so for wall's,. Box mapping or Planar mapping should work well
The more complex the shape of the model, the more you need to think a little bit about which direction the texture should be projected onto model,. and either split the object into shading domains with different UV mapping, or use UV unwrapping to create seams and flatten the mesh into a UV layout.
Thanks for explaining... that is the idea I got even though it was only briefly mentioned... video was about something else .
Makes perfect sense. I knew to leave Texture 0 shading domain alone and to create new ones for user shading domains. I think of Texture 0 as the default shader color/settings... but might be wrong about that. I'd been unaware of UV unwrapping until reading the Forums, begining late last summer. I can see where they would help especially with a texture map or complex objects. At the moment I'm only working on less complicated objects and creating shading domains for different areas and directions.
In the UV Mapping and Unfold discussion UV mapping seems to be covered very well by you as well as others.
Not long ago I was having a problem adding Carrara's "Pattern Function/Brick" to an object... finally figured it out. Brick as well as some others are 2D shaders seem to look nothing like they should unless the settings are correct. After getting the results that I wanted on a simple "plane"... I saved it out as a .car scene to refer to later. Pics are included but only for an example... I'm sure there are other ways of setting them up. Please note the addittion of Bump... see pic for very simple explanation. Note that I had no luck when setting Direction to Horizontal... the vertical grout was much larger than the horizontal grout. :( Perhaps it might work better on a non-perfect square???
I normally go to the "Global" tab, in the vertex modeler, then "Rename" the "Texture0" (default shading domain) to something that fit's the model i'm working on,
although i'll often start modelling and defining new shading domains as I work,. and at some point I'll go back to the global tab and rename things to suit, before jumping into the shader editor to create the shaders for it.
As MDO2010 points out above,.. Carrara's shaders have some powerful features,. for UV projection,. these "over-rule" the existing UV's for the model,. but they don't delete those UV's,. so it can be a quick way to preview different mapping options directly on the model.
Glad I mentioned Texture 0... I learn something everyday.
Below are pics of how my Walls are coming along. 1st pic shows that I've walled myself in. :) 2nd pic is areas that I'll need to work on next... marked with "+" are entire walls which have no vertices except at corners... showing where I'll want to add vertical structure, lines/polys, for openings in the future. The 2 "X"s mark places that have problems... along the way I ended up with a poly inside another poly only at one place.
One side wall was very easy... I just grabbed an entire line of vertices and moved them to the location I wanted. On all the others I created duplicate vertices and then moved them into position and used Weld first then Link next after which I selected 4 vertices at a time and used Bridge to fill the polygons. Once I figured out what to do it went very quickly. Worked on it late last night/this morn and think those are the steps I took before stumbling off to bed.
After fixing errors and adding more vertices I'll probably save this as a quick start for any other additional rooms or other buildings. Before punching holes for doors/window/etc... of course.
Note that I pitched my earlier idea for adding side walls... there would have been too much welding going on. With all the papers laying about I didn't want to take a chance of starting a fire. :)
TIP: Once something is learned how to do properly... do it again and every once in a while until it's burned into one's memory.
Just got through cobbling together this egg shaped chair. Started with a vertex sphere. Used soft selection to stretch it into an appropriate egg shape. Lopped off one side. Added thickness to make the outer shell. Selected the polys on the inside surface and copied and pasted them in place to start a new polymesh. Added thickness to it to create the inner cushion. selected all and tilted back to a chair-like position. Took another sphere and lopped most of it off to make the stand. Again, soft selection was used to stretch it into shape.
Comfy looking... I could fall asleep in it myself. :)
Just had to crank up Carrara again tonight to give it a try... unfortunately my egg-shape was a bit deformed... should have selected the shell from the back instead of the inside. I did use "soft select" and "add thickness".
Tip: When you know you're going to need a copy of the mesh (e.g. for cushions, or the liquid inside a bottle etc), copy it before you add the thickness. Trying to select the inside polys later can be a real hassle! You can always hide the copy until you need it (or shunt it out of the way - with snap to grid on, for when you want to shunt it back)
For awkward selections,. like the inside of a bottle,. you can select the outside surface,. then use Selection / Hide Selection, to allow you to see, and work on, the inside surface.
Selection / Reveal Hidden,. brings it all back.
It's also good practice to get into naming things as you work,. whether it's a Model, a selection of polygons, or shading domains,. then you can use select by name to quickly select.
Apply UV mapping to any object before duplicating it in the modeller,. it can be a real paint to individually select and UV map lot's of the same thing, one at a time.
Learning from mistakes. The image below shows what happens when everything seems to have gone wrong... my own fault of course. :(
Having created polylines/polys for each side wall with success I got a bit too experimental on the final two walls, inner and outer, which are 2 different polymeshes. Listed are wrong things I did as well as others that will not work.
Never: Move parts of connected, 2 or more, polymeshes while other parts are hidden to extreme locations unless you know where the hidden ones are. Well not "Never"... just don't get carried away as I did this past night.
Wrong: First I hid the walls not needing polygons/polylines. I then wanted to see if I could use Symmetry to create everything I did on one wall as well as the other at the same time. Unfortunately the Symmetry hadn't worked when I tried it for the side walls, it's Yellow Direction line was in the wrong place. Wanting it to work I positioned these 2 walls to have the Yellow line to be inbetween each wall. Still no luck of course. I then chose "Reveal Hidden Vertices" only to find that what was hidden was in the original position while the 2 walls were still where I'd I moved them to. The result after trying to get the 2 walls back to where they belonged is shown in the included pic.
Why: I'm a numbskull. :) These are 2 different polymeshes.. an inner and and outer wall not connected to each oher.
So what caused the rather strange look at each narrow end??... I suspect it was my manually trying to reposition the longer back wall after trying to use Symmetry on 2 polymeshes. I just checked the Normals, thanks 3DAGE, and some face inwards and some face outwards on the same walls... those Normals are now all helter skelter pointing one direction on one poly and point another direction on others. Reverse Normals doesn't fix this for me... it affects the entire model even when only one poly is selected.
Next step... load my earlier version with correct Normals and leave Symmetry alone. Note that I have used Symmetry on a single polymesh object with very good success.
Hi wgdjohn. You are making progress. Here is a workflow suggested by Roygee and similar to what folks have been suggesting. For a building with doors and windows, you can use the polyline tool to lay out the blueprint and then use ruled surfaces to create the building. From the top camera in the vetex modeling room, select the polyline tool (and probably enable snap-to-grid), and place a point at the corner of any exterior wall, at the edge of any door, and at the edge of any window. If a window or door is going to be a strange shape, place a point wherever it changes direction. Then in the vertex modeling room duplicate the polyline and raise it to the bottom or top of any door or window. Duplicate again and raise again to the top or bottom of any door or window. Repeat until you get to the top of the wall. Once you have the polylines, use the ruled surfaces tool to create the mesh from the polylines. (note that you have to delete the polylines as they are not part of the mesh).
You should now have the outer walls of the building, and there are verteces outlining the doors and windows. Select the polygons for each of the doors and windows and duplicate and move away from the building. Ultimately, the polygons for the doors and windows will be copied and pasted to newly inserted additional vertex objects. Once new objects exist for each door and window, return to the building and delete the walls where the doors and windows need to be. Then edit the models to taste, especially the windows, and add thickness. It is usually a good idea to add slightly greater thickness to the walls than the doors or windows. When I add thickness to the walls, I generally prefer to use a negative number to thicken inwards. In the assemble room, move the doors and windows to the holes in the building. As desired, uvmap and create shaders.
Here is an example. Although I created the polygons for windows, I only actually placed the door in this example in the interests of time.
This is a REALLY cool thread!
As it's been a lot lately, my time to forum peruse/ask/answer/otherwise communicate is very limited. I glanced through most of this thread and really love what's going on! Fillet beveling, spline beveling, deformer modifiers... really cool ~ with excellent (it seems at a glance) feedback from some very experienced Carraraists... love it... gotta find the time to READ the whole thread from start to finish.
Just my two cents, keepiung the title of the thread in mind:
I never use n-gons.
Flattening a cylinder to make an arch is referring to the cylinder being made laying on its side, so the rounded edge on the bottom half needs to be flattened. Great way to make arches... except that I find it easy (would say "easier", but I've never tried the flattening method for this) to simply select to vertices that form an arc on the bottom, and delete them, then add thickness, weld, whatever I need to do to finish the shape.
I really enjoy simply starting with a cube and use the various symmetry axis with extrusion to model out my shapes. I'm always thinking about how I'm going to make my UV map allocations as I model.
Speaking of UVs, I have to bring up UV Mapping, since it's an essential part of the modeling process. Phillip Drawbridge's Star Ship models that I have use the projections in the Texture room to map his excellent models - and I love them! I'm not sure if that style of mapping requires as much fore-thought or not (?).
I actually started working with UVs before I ever tried modeling - creating community content for the game: Neverwinter Nights. When I first started working with UVs in Carrara, it felt kind of clunky and difficult. Very touchy.
Nowadays, I find the UV tools in Carrara to be quite excellent to work with. As WDJohn mentions regarding the modeling tools: To get to grips with something, we need practice.
One important thing that I'd like you to wrap your haed around is that: we don't have to stay within the visual grid in Carrara's UV editor as we map oiut our UVs. Learning (figuring out through practicing) this has really made everything a LOT easier for me.
As mentioned by 3dage earlier, it REALLY helps (for many situations) to create specific material zones on the mesh. These different zones may then easily be mapped individually, without changing the mapping of any of the other zones - but there are important steps involved to make that statement true:
Detach Polygons - Make sure that, if you'r going to map a single material zone, expecting to do so without dragging around vertices from other zones, you'll need to "Detach Polygons" before you start changing things. It's right towards the top of the Operations tab.
Selecting Vertces and/or Polygons - Make sure that, if you'r going to map a single material zone, expecting to do so without dragging around vertices from other zones, do your intial selecting via the Sections menu on the interface at the top. Selections > Select By > Shading Zone > select your intended zone. Then use the translation (t) to carefully grab the selection and drag it out of the grid, away from anything else. Now we can grab parts of the mesh by dragging our selection around any pat of the zone very naturally and easily. Otherwise, if you drag select vertices from where it originally sat in the grid area, you'll actually be grabbing any vartices/polygons/edges that lie in that same area of selection - even if you have them invisible via only showing the selected matieral zone.
Just some quick 'Food-for-Thought' stuff that I fing to be extremely important to ANY modeling endeavor.