The Woes of UV mapping...

cdemeritcdemerit Posts: 502
edited February 2015 in Hexagon Discussion

So I've seen countless demos on how to uv map stuff, even some seriously complicated shapes, however when I try, I get a garbled mishmash of a mesh. I'm trying to map my object, I use the seaming tool to break it apart some, and it's still a bit of a mess, but when I try to clean it up, 80% or so of the time, it wont let me move the uv map. I can click on points, they light up, but the movement arrows don't appear. then when I do get them to show up, I can move two or three things, then have to reposition the screen, and I'm back to the not allowing me to move anything... It's starting to drive me bonkers... Any tips?

Oh did I mention the frequent crashes when trying to uv map?

Post edited by cdemerit on

Comments

  • RoygeeRoygee Posts: 2,232
    edited December 1969

    Yes, indeed, the woes:)

    To be able to manipulate the UV mapping, you need to have validated the mapping and have the cursor in the UV map window.

    Hint - if you have the model and UV map both open, when you select on the model the selection will be shown in the the UV map - makes it a lot easier to know exactly what is selected.

    Hex does not enjoy too much messing about with UV maps - especially "undo"!

    Perhaps if you post a screencap, showing the model with seams and pins (cursor must be in the model window) and the UV map, we will be able to give you more assistance.

  • Wee Dangerous JohnWee Dangerous John Posts: 1,283
    edited December 1969

    Agree with everything Roygee has said. One of the things I tend to try is using the X,Y,Z plus the U,V in turn to get the best result. By this I mean, when you've pinned the map the squares are roughly the same size, this reduces the stretching.

  • cdemeritcdemerit Posts: 502
    edited December 1969

    Well, When I can I'll, post some screens, but not tonight.

    The problem I believe is two fold. 1st is that I have no clue as to what I'm doing. 2nd is Hex has crashed on me several times during attempts to UV map. I do not know if they are related or not, or if it is something else.

    Basically, the item I'm trying to map is a freebie vanity that I got from ShareCG, and while it is pretty nice, the artist did some odd layouts, presumably to make the top appear to slope inward that really messes with the mapping. I've actually had a few problems with this object as in hex it looks fine, in blender it looks fine, but in Daz, when a texture is added to the top, a phantom plane appears. I was unable to fix that issue directly, but loaded the .OBJ file into hex, Saved it as a .3DS file, imported it to blender, where I saved it as a .DAE file which was imported to Daz. (So I'm betting there was some corruption in the .OBJ file.) Doing that, The vanity was broken into it's parts, and I was unable to save it as a prop. Sent it back to Hex, applied the UV mapping to the parts, which did well, until I merged them into a single form, which messed the maps up. Stared over, got 4 surfaces to look good, and totally messing 3 surfaces, all of which are unseen, leaving one surface that is not right but acceptable. Any attempt to fix that last visible surface leave the whole thing in total mess.

    As for Hex's Undo Button, Why do they even have it? It's about worthless.

    But in the end, the biggest issue is I cant select the points and move them when I want to, a majority of the time, even though I was doing just that a moment earlier. This isn't so much a question that can be answered, but more of a statement with hours of frustration.

  • WendyLuvsCatzWendyLuvsCatz Posts: 23,295
    edited December 1969

    :lol: I should not be posting here as Hex does not even like me modeling in it on my machine it freezes!!
    But
    I found the same with Carrara when it came to UV mapping
    my solution is to use Ultimate Unwrap 3D which I bought more for direct X conversion and polyreducing but nonetheless it is a good UV mapper too!
    I suggest try one of the free Unwrap programs first and see what suits you best.

  • atticanneatticanne Posts: 3,009
    edited December 1969

    I've never tried this, but I know that sometime I will have to bite the bullet. You guys are scaring me off. Hexagon? No way. There has to be something else I can use. I tried it early on and got absolutely no where.

    Now, back to my quiet lurking mode. Keep posting and I'll keep reading. At least when I try it I will have heard of it.

  • RoygeeRoygee Posts: 2,232
    edited December 1969

    The problem I believe is two fold. 1st is that I have no clue as to what I’m doing. 2nd is Hex has crashed on me several times during attempts to UV map. I do not know if they are related or not, or if it is something else.

    Most assuredly related - we have all found that the more we use it, the less it crashes. Somehow Hex adapts to the user :)

    I fully agree with Wendy regarding UU3D - not because Hex doesn't have good UV mapping, but because I tend to make large, complex models and UU3D gives many more options than an be found in Hex, Carrara or Blender.

    The undo works really well - just not with UV mapping :)

    Can you post a link to the freebie for me to take a look at? Your reference to a ghost surface sounds very much like a bad n-gon, which DS cannot handle.

  • FirstBastionFirstBastion Posts: 4,599
    edited February 2015

    You can use other tools too. Hex works great for model creation. It's fast and efficient. Its UV mapping functions though are more limited. So I'll select seams and unwrap a model in Hex. Validate. Save out an .obj, then open the obj in some other UV mapping program, like UVLayout or UV Mapper pro to fit the maps and assign material zones maybe relax a mesh if necessary. Use whatever workflow techniques and tools that get the job done. There is never just one way to do things.

    Post edited by FirstBastion on
  • cdemeritcdemerit Posts: 502
    edited December 1969

    Roygee said:

    Can you post a link to the freebie for me to take a look at? Your reference to a ghost surface sounds very much like a bad n-gon, which DS cannot handle.

    Sorry for the delay... I started a new job this week, and didn't get a chance to work on this.

    So the original file: http://www.sharecg.com/v/43691/browse/5/3D-Model/Bathroom-vanity-sink-faucet

    As it was when loaded into Daz, and texture files applied: http://i.imgur.com/oOJTXEO.png
    The textures are the same as the ones you'll see on the final mostly fixed item. clearly no UV map was loaded or it was lost in the load.

    As loaded into Hex from the .obj file, not transferred from Daz. : http://i.imgur.com/6696PFa.gif

    And after playing with it for a day or so.: http://i.imgur.com/QZySmwH.png
    All but one visible surface remapped to my liking, I just could not get the back splash to map correctly. Also, at some point I want to remove the lines on the counter top that leave those black shadows... but for right now... What you don't see it the total smears that are the bottom and the back... Technically the front too, but there is so little visible surface, the front isn't bad.

    But it took way too long to do...

  • RoygeeRoygee Posts: 2,232
    edited December 1969

    Wow - where to begin! :)

    The zip file contains .hxn, .car, .obj, 3Ds and .mtl files. What the .mtl file is there for, I have no idea, as there are no textures supplied.

    The .hxn file has so many n-gons that it crashed when I tried to export as .obj.

    The .car file appears to work OK.

    The n-gons on the counter top of the .obj file have been "corrected" through triangulating, but the cabinet has not. The mass of triangles converging on points in the corners, as well as the n-gons on the cabinet cause rendering artifacts (shadowing) in DS - other applications can handle these anomalies, but not DS.

    Additionally, the chamfering on the edges of the counter top are long, thin triangles - never a good modelling practice.

    The only UV mapping is for the waste pipe - very strange.

    All the components of the model have been welded in the .obj file, making UV mapping really difficult. I certainly would not like to tackle the job in Hex.

    The best bet is to import the .3DS file into Hex, UV map it because the components are kept separate, so it would not be too difficult to do, then export as .obj for use in DS..

    The .3DS version does not contain n-gons, but, as can be seen in the attached render from DS, the mass of triangles on the counter top make ugly artifacts. This may or may not be corrected by texturing. I don't know enough about texturing in DS to hazard a guess.

    If it was up to me, I would dump the counter top, back-splash and cabinet and re-make them - this is pretty simple to do and would be a lot less work than trying to fix.

    It appears the maker of the model did a Boolean cut on the counter top for the basin. This is not necessary - the basin could simply be sunk into the counter top. If, for the sake of purity, you find it necessary to have a hole, there are more efficient methods of doing this than a Boolean cut, which will not result in those ugly tri's converging on the corners.

    vanity.jpg
    600 x 600 - 64K
  • Cris PalominoCris Palomino Posts: 6,536
    edited December 1969

    I agree, this is a poorly made model in many respects. Overkill on the basin hole. Loops added where they will not be seen and provide no real support to the model. Added no loops where needed and instead relied on flat shading which is fine if you don't mind faceted details...just made no real sense.

    Sometimes it's best, as Roygee points out, to redo some parts to make them cleaner.

    As far as UVs are concerned, hard surface modeling, like this, is much easier to UV unwrap since you just deal with making clean surfaces that have as little stretch as possible. I gave some advice on using UV grids to help with unwrapping in this thread.

    Take some time to look up some tutorials on UV unwrapping. While the mechanics of how you do them, specifically, can vary from program to program, the thinking behind how you choose to unwrap is pretty much the same in all. With hard surface, you're very often unwrapping boxes and tubes and such. So it's where do you choose to put the seams. The ultimate goal is to unwrap, which means laying out flat, what was once 3D. Think of boxes and how they are designed to open flat, or cylindrical objects, where the cap ends are separated, and there's a seam down the cylinder to lay flat. It's all the same with these items. You're going from complex forms to simple forms.

Sign In or Register to comment.