Help with UV problem?

DarthDDarthD Posts: 259
edited February 2015 in Hexagon Discussion

Some of my objects are not displaying the assigned texture. It started with one object when I was tweaking the texture in Photoshop. Everything was working fine then all of a sudden, the object turned white. There is nothing wrong with the texture because I can send the object to Daz and assign the texture with no problems. I guess I should say I have to assign the texture because it will not send it to DAZ.

Also, now when I create a new object and map it, send it to DAZ and assign a texture, It works great. But, when I send it back to Hexagon, the object turns white and it will not display the texture even if I assign it again.

I want to adjust the UV Map but that's impossible since I can't see the texture.

I have other objects in the same scene that I can transfer back and forth with no problems.

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Post edited by DarthD on

Comments

  • DarthDDarthD Posts: 259
    edited December 1969

    This one has no texture applied but I can't see the grid. If I apply a texture nothing happens. Also, I have a lot of materials that are not used. This is the only object in the scene. How can I remove unused materials?

  • DarthDDarthD Posts: 259
    edited December 1969

    I exported it as an OBJ without UVs then imported it back in a new scene. I remapped and still have the same problem. I created a cube and its working as it should.

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  • DarthDDarthD Posts: 259
    edited December 1969

    Also, when I select one of the three different types of mapping, nothing changes.

  • patience55patience55 Posts: 7,006
    edited February 2015

    Okay .... you see that little "Checker T" page, ALL the uvmap must be on it in order for texture images to display properly even later on in D/S and/or Poser, etc.

    BUT before you spend too much time making the uvmaps, it is best to finish modeling the item. if you apply level 2 smoothing to the item being displayed, you'll see what I mean. The edges all require some tessellation lines to hold the shape.

    Then remove "all" shading domains and apply a uvmap. I tend to prefer "plane". It may ask if you want to replace existing gizmo, say yes. You may also have to click the "new" button beside the x,y,z buttons.

    After all the Shading domains are made, then if you want them to have their very own uvmaps, you could redo them BUT you cannot do unfolding, etc. Generally speaking many can be manually resized, repositioned just as well.


    To see changes, one can assign a Checker T {just pick anyone, program makes lots} to the material, and use "lines" for selecting and moving the uvmaps around. Just be careful that all the correct lines are selected as that function tends to unselect a bunch very easily.

    Another reason the texture may not be appearing is if it was assigned a material which in this case was white.
    Or ... if the existing uvmap was made in such a fashion as to not be seen. If "faces" are selected but there's no "face normal" to select inside those lines, it's then very much that the uvmap needs to be remade.

    Post edited by patience55 on
  • RoygeeRoygee Posts: 2,247
    edited December 1969

    First off - the UV mapping looks pretty bad, with lots of overlapping and bits and pieces all over the place. Secondly, much of it is off the grid - all islands must be on the grid for the texture to show on the model.

    Thirdly, if you look at the settings at the foot of the UV window, there is a setting for the visibility of the texture - you have it set at 0.300. It needs to be set at 1 to get full, opaque visibility.

    To remove materials, click on the little arrow next to each in turn and select "Remove material" - unfortunately, this cannot be done in bulk.

    Once you have got all that sorted, load the texture through the materials tab - you will probably have to flip it vertically to get it to display correctly.

  • DarthDDarthD Posts: 259
    edited February 2015

    Thanks for the help. The stand is meant to be low poly for now. I'm mostly just experimenting with texturing. I still can't get it to show the texture on the object. I created the bowl which worked fine until I exported it to DAZ then back to Hexagon. Now it will not show the texture in Hex. I created the pitcher to show that it does work initially.

    This is the washstand. I know its not mapped properly but the grid should still show on the object.

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    Post edited by DarthD on
  • DarthDDarthD Posts: 259
    edited December 1969

    Here is the bowl.

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  • RoygeeRoygee Posts: 2,247
    edited December 1969

    I think the problem is that you are using projection mapping on objects which simply don't lend themselves to that method. Take for instance the jug - by the checkerboard pattern, i take it that is projected, probably from the spherical projection. The shape is too complex for that approach. I don't see the UV map for that, so can't really judge.

    Then there is the bowl - this is double-sided, but it appears that this was also done using a projection method, so the inside and outside are superimposed. Not too bad a method if you want the inside and outside textures to be the same.

    What you need to bear in mind is that there are two totally distinct methods of UV mapping - simple projection, using the first four icons in the row under UV mapping and actually "deconstructing" the model by cutting it with seams, using the head next to those four. Projection mapping is only suitable for very simple shapes, such as the bowl. For everything else in the scene, you need to unwrap it to get an accurate UV map.

    I took the liberty of modelling the washstand and UV mapping it - see the attached pic. This is what the UV mapping should look like - not saying it is optimized for whatever texture you want to put on it, but it should look something like this.

    One of Hex's big drawbacks as far as UV mapping is concerned is that it only allows for projection in one of the three axes on a single mesh. As example, for the washstand, ideally I would do an unwrap of the legs in either he X or Z axis, the sides of the shelves in the X axis and the actual shelves in the Y axis. Being restricted to one axis meant i had to choose one, then spend a lot of time untangling the spaghetti, and reassembling it. The actual modelling took about 5 minutes, with another hour spent reassembling the UV map.

    What could be done is to cut up the model into its component parts and unwrap each in the optimum axis. Another method would be to delete three of the legs and one of the shelves, UV map those and replicate. Saves a lot of work, but means that your texture would be repetitive and boring. Doing it the way I have done allows you to make subtle changes to the different parts of the texture map and introduce some variance.

    In any case, if you followed the advice in my first post, you should at least have a texture showing on the grid, even if it is not correctly shown on the model.

    If you bundle up the .hxn file, plus whatever textures you intend using, and maybe a render of what you have in DS into a zip file and post it somewhere like Dropbox, PM me the link, I'll take a look and see what I can do to advise you further.

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  • DarthDDarthD Posts: 259
    edited December 1969

    PM sent

  • RoygeeRoygee Posts: 2,247
    edited December 1969

    Received, thank you :)

    I would have liked to see the full file, including the bowl and pitcher to take a look.

    First observation was that, if the original model has a texture on it, it must have been a procedural texture, which does not need UV mapping, because there is no way the model you sent me, with the UV mapping as shown, could have held a mapped texture decently.

    If you look under the options for texturing in the materials panel, you will see an option to load a texture checker. This is very handy to check that the uV mapping is correct. Good UV mapping will show a clean checkerboard, evenly spaced. The first pic below shows what the original I received from you looks like. The checkerboard is distorted, especially on the legs - the white part shows where UV mapping for the top of two legs are outside the grid, so will not get any texture allocated.

    In the second pic, I have disassembled the model into its component parts so that I could do planar projections from different axes. You can see the checkerboard is evenly distributed, without distortions and all of the UV map is within the grid, so all parts get texture. It imports into DS as a single entity, so should work for you.

    This map is not ideal, but will take a texture. Ideally, I should use the unwrapping option instead of planar projection, but, with Hex being limited to a single projection axis, it means going through a lot of fiddly work to get everything sorted out and has to be "eyeball" scaled, as another of Hex's failings for UV mapping is that it does not do proportional mapping.

    I have checked the UV mapping by 3D painting a wood texture on it and it works just fine:)

    I will post the corrected file, with some suggestions on how to get a texture onto it, to Drapbox and PM you the link.

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  • DarthDDarthD Posts: 259
    edited February 2015

    So when you loaded it, the checkerboard showed up on the model with no changes to settings?
    I had the map laid out neatly when I first made it, with an even checker pattern across everything. I applied a wood texture to it and it looked good. I decided to try a few other textures. For no apparent reason my model turned white and I no matter what I tried, I could not get a texture to show up again. In my frustration I decided to start over with the UV mapping but I could still see nothing but a white model even though the UV window shows a checkerboard. I had no reference to adjust the UV map because I could not see the checkers on the model.

    The bowl did the same thing when I transferred it to Daz then back to Hexagaon.

    I'm working all weekend so I don't have any time to do anything right now. I'll upload the file with all three objects tomorrow.

    Post edited by DarthD on
  • RoygeeRoygee Posts: 2,247
    edited December 1969

    OK - I see what you are getting at :)

    Yes, when I loaded it directly from your post, without any changes, it gave me the distorted checkerboard - after I had made a new material and selected the checkerboard.

    The first pic shows it "as is", with a wood texture applied through the materials panel. If you look closely, you'll see that the texture is distorted - the white are is where the tops of the legs are outside the UV grid.

    The second pic shows the same texture on the re-mapped version.

    What you need to do to get a texture loaded is to remove the current material, select the def-surf-mat shading domain, make a new material and in the drop-down menu select texture image and load from there. You will then be able to manipulate the UV's to get the texture aligned correctly.

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  • Cris PalominoCris Palomino Posts: 11,151
    edited December 1969

    I always recommend using a more detailed uv grid to check your UVs. These here are very nice because there are differing colors as well as letters and numbers. The reason for the letters and numbers is because they can alert you when you have overlaps and/or flipped UVs; they also allow you to determine direction and stretch.

  • RoygeeRoygee Posts: 2,247
    edited December 1969

    I fully agree with cris that using more sophisticated texture checkers than the default one supplied with Hex gives better results.

    BTW, a little more messing about with the wash stand showed that using the box projection method gives a pretty reasonable result, if you are not up to the full unwrap method. Not ideal, but good enough as a starting point to manipulate the islands for better results.

  • DarthDDarthD Posts: 259
    edited February 2015

    Thank you! That worked! I wish I knew what happened to mess it up to begin with. I'll definitely go with a full unwrap. Cris, Thanks for the link to the grids, they will help a lot. I still don't understand whats going on either. I never had to select def_suf_mat before. I didn't even have the shading domains window active.

    Post edited by DarthD on
  • RoygeeRoygee Posts: 2,247
    edited December 1969

    Glad you got it sorted:)

    This is the first time I've seen "def_surf_mat" in the shading domain. If you had somehow accidentally selected all the faces and made a new shading domain without naming it, it would default to "domain0". This probably came about in your export settings from DS, although I don't have a clue on how, not knowing much about DS surfaces at all.

  • DarthDDarthD Posts: 259
    edited March 2015

    I haven't had much time to work on it but this is what I have so far. I need to fix the rim of the bowl and I'm still not happy with the wash stand texture

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    Post edited by DarthD on
  • patience55patience55 Posts: 7,006
    edited December 1969

    Roygee said:
    Glad you got it sorted:)

    This is the first time I've seen "def_surf_mat" in the shading domain. If you had somehow accidentally selected all the faces and made a new shading domain without naming it, it would default to "domain0". This probably came about in your export settings from DS, although I don't have a clue on how, not knowing much about DS surfaces at all.

    I've seen that now and then. Not 100% sure as to why and/or what triggers it except that when D/S is importing an .obj, it expects there to be a uvmap AND material(s). If the materials aren't set, it will make some up.

  • RoygeeRoygee Posts: 2,247
    edited December 1969

    So studio is the guilty party :)

    @DartD - what is it you don't like about the wood texture? I think you've done a great job - authentic looking, with that aged, well-scrubbed look and cracks. The wood grain is running correctly and there is variety in the individual planks.

    Maybe give the bowl rim a bit of chamfer to make it look more solid?

    Your choice, but I'd suggest that if you were going for the farmhouse look, rather have a flower pattern on the bowl and jug.

  • DarthDDarthD Posts: 259
    edited December 1969

    The crack on the front left wraps around and looks unnatural to me si I want to adjust it so it's just on the top. Other than that, I think it looks good. I just used the marble texture to stick something on them but I like your idea of a flower pattern. I'll see what I can find.

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