You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts

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  • shogunato
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    shogunato polycounter lvl 9
    Many thanks for the reply
  • shogunato
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    shogunato polycounter lvl 9
    I spend 2 day to understand what is wrong. This makes me crazy



    Workflow
    1. From Max 2016 : - Export all mesh (low, high, cage) using FBX 2013 with 1 smoothing group mikkTspace (with export smoothing group ON and Tangents & Binormals OFF) for the cage and low res mesh, all transform freeze for all meshes and only the cage and low res mesh are triangulated

    2. Baking  in Xnormal 3.19.2 with Mikktspace "Compute binormal in the pixel shader" checked. Baking at 2048 X 2048 pixel. Normal map Swizzle Coordinates = X+ Y- Z+
    3. Import the same low res mesh into UE4 with the "import normal" option

    4. Baking in Hnadplane with unreal engine 4 preset
    5. Import the same low res mesh into UE4 with the "import normal" option
    Files :  https://www.dropbox.com/sh/1s68spha2l7sfvd/AACbGNl1WExZG1U-rMuF8luEa?dl=0

    I would love to have some advices to explore :):)

    edit: here what i've got by exporting tangent binormal and hard edge workflow






  • ZacD
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    ZacD interpolator
    The remaining artifacts in the last image just look compression related. 
  • shogunato
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    shogunato polycounter lvl 9
    yep, looks not so bad with hard edges workflow but i would really like to use mikktspace
  • Nominous
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    Nominous polycounter lvl 5
    In that Handplane video on page 1, I understand that the UV layout for the left sphere causes the vertex count to double. The author states that the resulting tri count is 107 while the original was 96. However, I count 15 edges where the UVs lie. Shouldn't the resulting tri count be 111?
  • NoRank
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    NoRank triangle
    So when you're using a synced workflow you have less vertices since you have less uvshells and less smoothing groups, still it has it's own drawbacks. So my question kinda goes to, is it really a hard positive impact on performance or just a minor thing nowadays? 

     I know it's a good practice to have everything as optimized as you can, was just curious about that.
  • ZacD
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    ZacD interpolator
    NoRank said:
    So when you're using a synced workflow you have less vertices since you have less uvshells and less smoothing groups, still it has it's own drawbacks. So my question kinda goes to, is it really a hard positive impact on performance or just a minor thing nowadays? 

     I know it's a good practice to have everything as optimized as you can, was just curious about that.
    Optimizing polygon counts is generally a waste of time, especially down to that level. Quad overdraw is the main tricount related performance impact. Sometimes dynamic shadows are effected by the tricount, like Cascaded Shadow Maps in UE4. But you can use a lower polygon mesh as the shadow caster if that's an actual issue. 
  • Saiodin
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    Saiodin polycounter lvl 5
    Hello.
    I'm having a problem with my edges and am wondering by now if this is an actual problem or just a limitation. I've read this thread and others and searched for the last days, but I just can't to pinpoint what exactly my problem is. I've tried to follow the advices as close as possible regarding UVs and hard edges, cage etc.


    My edges have "seams", which are mainly the actual edges of the low poly edges. But I think there is something else wrong here with the normal map. I'm using Maya 2016 and Substance Painter 2.





    I know there are some other issues in there, but I'm focusing on that edge issue and it's killing me.
    Thanks for any advice.
  • metalliandy
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    metalliandy greentooth
    @Saiodin It looks like a texture filtering issue, which unfortunately is not fixable by artists. You will always get these problems when camera is so close to the corner like that even when everything is perfectly synced.

    In the screenshot below you can see a similar error even when an OS normal map is applied (OS normals totally ignore the vertex normals of the underlying low poly mesh so errors from vertex normal issues are impossible) so it would be best to just live with it and move the camera further away. You will never see these seams under normal circumstances.


    Hope that helps :)

  • Saiodin
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    Saiodin polycounter lvl 5
    @metalliandy Thanks for the answer! That does help me a lot : )!
  • metalliandy
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    metalliandy greentooth
    No problem @Saiodin
    Happy to help :)
  • Ballo
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    Ballo polycounter lvl 9
    First images of Earthquake are missing, shame is a perfect post to explain hard normals to my students, anyone has a pdf. or something with the post? thanks
  • EarthQuake
    Ballo said:
    First images of Earthquake are missing, shame is a perfect post to explain hard normals to my students, anyone has a pdf. or something with the post? thanks
    Images should be fixed now!
  • Twinflower
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    Twinflower vertex
    btw, this is probably just camera clipping or some aliasing but to me it looks like its due to the hard edges.

    you getting incorrect shading on the out edges on both of the hard edge models

    areas in red should be like areas in green
  • Udjani
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    Udjani polycounter lvl 2
    Can someone help me please!, have read and reread everything, when i finally tought that i was starting to make sense of it, end up confused as fuck again. 

    After read almost all of the coments here, bouncing back and forth btween the topics and my tests, i did make some bakes that end up lokking no that bad i think, and i guess i understant the ''2 diffrent workflows'' for baking normals. 

    However iam now having problem with i think may be due to ''synced'' workflow issues, which makes me even more confuse, since earlier this week i did a test bakes with this very same model and with the same smoothingsplit/hardedges, and didn't had those shading problems, so i have absolut zero idea of what im doing wrong. 

    Have importet them to marmoset and skechfab, pretty much the same problems for all 4 of them, with little difference between.

    1 - Hard edges/smoothing splits + cage.
    2 - "1 Smoothing group" with support edges.
    3 - "1 Smoothing group"
    4 - "1 Smothing group" with less uv shells (did this only to see if it would have a big impact for having less uv shells, so it can be ignored)

    Only the one with hard edge have some weird artifact in the blender viewport, which i don't know what is causing that either, but pretty much all of them display well in both the blender viewport and cycles render. 




    The shading errors in skechfab

    This model is suposed to have mirrored uv, for the upper and lower part, could that be causing it?, however as i said, i did some tests before the same way, and even having the normals looking worst, they dindn't had those weird shading issues in skechfab/marmoset.  

    Obs: i have already flipped everything. 



    Also have uploaded them to download if you want to take a better look. \/

  • EarthQuake
    @Udjani Make sure the tangent space in Toolbag (in mesh properties), is set to the same as your baker. Or just bake in Toolbag, as it will bake with the tangent space that your mesh is set to. Mikkt is generally best if you don't know which t-space to use, as that is what Unreal and Unity use these days.

    Also, make sure that the triangulation is the same in all apps.
  • Udjani
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    Udjani polycounter lvl 2
    @EarthQuake Jeez, that was the problem, scratching my head bcz of the click of a button again. Thank you!
  • Irensay
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    Irensay polycounter lvl 2
    Hi, i'm trying to bake a simple geometry but i dont understand why is seems like this, it's only a normal map bake



    anyone can help me pls? it's important thank you
  • TannedBatman
    I have a vehicle composed of multiple parts e.g shell chair and details on the inside. Just wondering if anyone knew how to make it so the uvs are scaled the same across all the objects. Im using automatic mapping for this since its for a render not a game and I wont be using photoshop. Ive pressed automatic map and changed the scale but that doesnt seem to do it. Didnt think any pictures were necessary. cheers.
  • zackii90
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    zackii90 null

    I have a vehicle composed of multiple parts e.g shell chair and details on the inside. Just wondering if anyone knew how to make it so the uvs are scaled the same across all the objects. Im using automatic mapping for this since its for a render not a game and I wont be using photoshop. Ive pressed automatic map and changed the scale but that doesnt seem to do it. Didnt think any pictures were necessary. cheers.

    I guess you should merge everything into 1 object, unwrap it and separate it again (if you need). By this way UVs are scaled the same across all the objects but small objects may have not enough texture resolution. I think the best way is to merge objects into groups which should have pretty equal UV areas and use UV checker texture.
  • Peppek1993
    Hey guys, I'm having a slight issue with unwrapping certain type of polygons.

    I have a break along this line


    and when I unwrap this part (simple quick planar map, quick peel) it unwraps fine. Straight line of polygons.

    But when I unwrap this part




    it doesn't seem to do the job.

    It still unwraps as a circle on my map, and I don't want that.

    I don't understand. What's the difference? There's a break in the same exact spot on both of these and from a technical point of view it's basically the same shape.

    Could you help me out here? Thanks
  • Thanez
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    Thanez greentooth
    Hey guys, I'm having a slight issue with unwrapping certain type of polygons.

    I have a break along this line


    and when I unwrap this part (simple quick planar map, quick peel) it unwraps fine. Straight line of polygons.

    But when I unwrap this part




    it doesn't seem to do the job.

    It still unwraps as a circle on my map, and I don't want that.

    I don't understand. What's the difference? There's a break in the same exact spot on both of these and from a technical point of view it's basically the same shape.

    Could you help me out here? Thanks
    Wrong thread, but OK: They're not the same shape in 3d space though. Some are cylinders, and that 'circle' is a flat, planar set of polygons. Any smart unwrapper would try to do the same, especially if you have these UV islands in separate smoothing groups.
    Automated unwrapping never does exactly what you want, so you're gonna have to split that 'circle' along the same edge that the other bits are split, weld the edges you want welded, and either straighten the loops or relax the whole thing.
  • Mohamed_Salah_Bchir
    Hello, i'm not sure how a good clean normal map is supposed to look like. I baked this one from a high poly mesh in Zbrush. and below it is the UV layout from the low poly. The UVs in circle are supposed to be straps.
    My guess is, the geometry changed when i did the high poly and that translated to the UVs? does that mean i need new UVs? 
  • kat_sta
    Hi guys,
    I normally always try to find out by myself what the problem is, but here I have difficulty with addressing it, I am also not sure which program is making this.


    so here is my UV map, I moved object to Zbrush and modelled it and then start texturing it in 3DCoat. As I painted all and thought all is going fine, I went to Photoshop to put Unsharpen Mask on, and that's what I got


    I have no idea why all edges vanished and whole map became a blob. There is probably some setting somewhere that I am not aware of. Can someone be so kind and explain that to me? Thanks in advance :3
  • zachagreg
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    zachagreg polycounter
    @kat_sta Are you talking about the padding? Certain programs will add padding around UV shells to protect against edge and color bleed when mipping down, also to prevent unsightly seems. Basically takes the edge pixels and fills in the spaces between the UV shells with the sampled colors. My guess would be that 3D coat did it because that's wehre you painted the map. 

    To fix this on the export window of 3D Coat there is a checkbox to turn off padding.
  • kat_sta
    zachagreg said:
    @kat_sta Are you talking about the padding? Certain programs will add padding around UV shells to protect against edge and color bleed when mipping down, also to prevent unsightly seems. Basically takes the edge pixels and fills in the spaces between the UV shells with the sampled colors. My guess would be that 3D coat did it because that's wehre you painted the map. 

    To fix this on the export window of 3D Coat there is a checkbox to turn off padding.


    Thank you so much, I didn't know about such a thing as padding! Thanks again :)
  • Vincent074
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    Vincent074 polycounter lvl 6
    This is probably a very simple question but I'm a bit unsure on how to handle simple board-like geometry.

    if you model a wooden plank that's only a few centimeters thick, do you guys usually make a highpoly model for it so you can  bake out the edges... or is it not worth your time? 





  • zachagreg
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    zachagreg polycounter
    @Vincent074

    What is the prop being used for? If a hero asset of some sort definitely model out each board of the box do some highpoly sculpting on it. If it's for a background set piece of such that will not be seen too close not necessary IMO. Make sure to do a good job texturing (add nails, scratches, some edge wear and the like). A little more info on what you want to do with the box/boards and we can give you more info.
  • Vincent074
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    Vincent074 polycounter lvl 6
    @zachagreg

    The thing you see in the picture is just a drawer in a dresser so definitely not a hero prop.
    but imagine it is a hero object, you would rather sculpt than just chamfer the edges in a highpoly smoothed version of it? 

    thanks for the reply
  • zachagreg
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    zachagreg polycounter
    If its just a drawer i would just make a box delete the top face and then shell it real quick with a custom front face. If this was a hero prop drawer I probably wouldn't sculpt it unless the front face had some fanciful design on it. Just standard hard surface modeling and would probably include the geo of the joints since those are a cool detail and then just bake it down to the lowpoly shelled box. 

    Image result for drawer wood joint

    Those with nice chamfers would look nice. All in all though it wouldn't take too long to throw together chamfers on the outer edges and bake it down so go ahead and do it since it will make it look better regardless. Its remarkable how just having some kind of edge chamfers brings up the quality of a model. 

    If you plan on destroying the drawer then sculpting may come into play. I originally thought the box was some kind of wooden crate made of different planks nailed together. 
  • Vincent074
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    Vincent074 polycounter lvl 6
    interesting, thanks for your input
  • TannedBatman
    Here is the uv for an object. Someone help me get it into shape or lead me in a direction after various failed attempts! This is after planar then cut and unfold. looks like a stomach and would rather it have more of a uniform checker pattern. Thank you. 

  • Vincent074
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    Vincent074 polycounter lvl 6
    TannedBatman
    is there some sort of relax function in maya?
  • zachagreg
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    zachagreg polycounter
    @TannedBatman
    Are you trying to get just that outside piece as a squarish island? If so the easiest thing to do is this:
    -Select the island
    -Hit Unitize under the Polygons menu in the top menu bar
    -Select all the edges then deselect your seam as well as the top and bottom seams in the viewport
    -Then Move and Sew UV's (or stitch together can't remember the nomenclature of that)
    That should give a square result 
    -Then relax just slightly to ease some of the stretching that you will get due to the nonlinear shapes in your mesh. 

  • TannedBatman
    Thank you alot. One problem is its a perfect rectangle and yet there seems to be some stretching on the edges which shows up really bad in substance painter.

  • zachagreg
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    zachagreg polycounter
    So the stretching occurs because as you can see those polygons are not perfectly square on your model. Therefore when you make them perfectly square on your UV layout it will stretch the texture. If you don't want stretching the most accurate layout would be closer to what you had before. 

    To alleviate some of the stretching run the Smooth tool a little bit over that rectangle. Granted this will kill your perfect rectangle but will result in less stretching across your mesh. Think of UV's as the wrapper of an easter bunny chocolate, not as a projection mapped onto an object.

    There are also some tools within Maya to show stretching like this.
    https://knowledge.autodesk.com/support/maya/learn-explore/caas/CloudHelp/cloudhelp/2018/ENU/Maya-Modeling/files/GUID-637CCCB0-3513-4DFD-A8D5-EB1AB5CCEB9D-htm.html
    Above is a link to the tool for checking UV distortion. 

    Image result for bunny chocolate wrapper

    ^
    I
    I
    That's what I mean by the Easter bunny thing.
  • sputman
    Hi - back in the world of Normal baking. I came across this thread whilst researching for a car model. There lots of process here but to break it down - would I ( In Maya ):

    - For any hard edges on the model make them hard 'Harden edges' option
    - Split the UV seams on those hard edges ( is this to stop gradients ? )
    - For any smooth soft edges use 'Soften Edges'
    - Use the Tangent space options in the normal map ( seems obv but checking - its a car )
    - Would anyone recommend breaking UV seams one hard edges with supporting edges?

    In the advanced section we have some settings
    - in the Match Using do I select 'Geometry Normals' or 'Surface Normals'

    Ive used the simple smooth everything and bake but i'm needing to add supporting edges at the door shuts seams. The seams seem ( lol ) to work but if there is a better workflow. I assume I don't need to actually break the edges. I don't think the openGl renderer supports hard edges - but i'll check. 

    Thanks in advance
    Steve
  • ZacD
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    ZacD interpolator
    Not a car modeler, but aren't most cars today completely geometry only using normal maps for decals or to add texture? Doesn't seem like baking a unique normal map for a car is common anymore. 
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