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CraigT

How to smooth bad model seams?

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Hey everyone - 

 

I've been using a C4D for a few weeks and have run into a challenge I was hoping you get help me resolve. I downloaded this airplane model, retextured it, but when I render, there are some seams (where the textures meet) that blocks the specular light from smoothly wrapping around. Attached is an image that shows these hard lines where the specular highlight gets stopped.

 

I found some tutorials using hypernurbs to smooth out rough model surfaces, however I'm using C4D R19 (no hypernurbs) and discovered using "Subdivision Surface".

 

"Subdivision Surface" seems to completely distort the model and the seam issue becomes much worse. 

 

Any ideas or tutorials that might help smooth out the model, so the specular light wraps naturally?

 

Thanks so much!!

Bf109 - Seam issues.jpg

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I would realy have to look at the topology of the model, its wires, and the Uvs.  Some models are not made for SDS as they do not have the structure to hold its forms, or it has triangles or even worse Ngons.  Also some texture models are done to work with linear Uvs others Non linear in which is controlled via the SDS tag sub divide Uvs with the standard boundry and edges modes.  The phong tag may also be causing issues.  First steps are to looks at the models wires as Im thinking it may have not be made for SDS in mind.  If you can share the scene that would get your problem solved much faster.  Next does it have a phong tag on the geometry, what are its settings, does the seams show without texture on it?

 

Dan

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  • Hey Dan - thanks for the quick reply. I tried to upload the C4D file (attached). The model I bought comes from here (https://www.turbosquid.com/3d-models/german-early-3ds/771578) - not sure if this helps. Let me know if this file helps or if you need something else. 

     

    I bought a couple of these models and hope I can get them all to work properly. Thanks so much! Craig

     

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    When used SDS and model has distortions, almost in all cases is problem with geometry. In your case imported model has a lot of disconnected parts/polygons. There is option to solve problem with welding those parts (optimize,untriangulate commands), but in many cases those repairs broke original mapping of texture (since added/modified geometry). So, when you try to solve model distortions, there will be more/less work with redesign UV´s and creating new textures...

    (but sometimes changes are not critical and could be used original textures as well)

     

    Another problem will be with SDS, because original model in some polyobjects hasn´t good polygonflow for subdividing (haven´t enough support edges to avoid shading errors on resulted mesh, which need to repair = redesign UV´s / textures...

     

    On other side try to remove normal tags and play with Phong tag setings. When model in result image/animation will not be close to camera, Phong shading could "fake" human eye :)

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  • Thanks for taking a look Bezo - I figured there was some poly-related issues. I bought 3 of these models and haven't worked on the other 2 yet, and figure they probably have the same issue. I'll play next with the normal/phong tag settings. I was hoping to use this model for some up close "hero" still images, and it looks like it will need a lot of Photoshop post work to make it look good. Not sure its worth it.

     

    Also - I'm fairly new to C4D and modelling in general, but could you point out a good tutorial for attempting to weld the parts to smooth them out. I don't mind re-working the texture and specular files at all, just want the simple geometry to work out - i.e. if light hits the fuselage, it wraps naturally around the surface.... :) LOL - just for the model to work in a basic environment.

     

    Thanks so much!!

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    bezo prety much covered it.  As I thought, its not compatible for SDS and as a result as already pointed out it can be fixed with the issue that C4D will break the UVs.  Later on Il run it through MODO as that dont break the Uvs in most cases.

     

    Dan

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  • OK - so Modo would be the next tool to take this through - to help make the fixes?

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    8 minutes ago, CraigT said:

    OK - so Modo would be the next tool to take this through - to help make the fixes?

    I will try for you later on or you can, yes it can weld without breaking Uvs, but it wont make is sds compatible.

     

    PS: Iv not had time to look at the Uvs but Im guessing each part uses the full UV space.  Once the parts are welded if thats the way you wish to go your need to make selection sets from the Uvs that belong to each part otherwise the texture maps wont work as all your Uvs will be overlapping.  I would also assume that the parts are meant to be separate as the original model anyway?

     

    When someone models without the intention to use SDS they use bevels instead where needed, if SDS are used on models without that intention everything that that no supporting frame work will smooth and look wrong.  Again Il repeat that I suspect what your seeing as a fault in the way its having seams may well be very intentional.

     

    Dan

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  • Hey Dan - thanks for offering to try it in Modo - if that's not too much trouble, that would be fabulous! I'm always looking to learn "how" so any tips you have after looking at this file, I can use them on the other 2 models as well. I have the texture maps I've been using - let me know how you'd prefer I send these to you - hopefully we can make this model look good! :) Thanks a bunch!!!

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    @CraigT, on the Turbosquid page it is listed as Max9 native. Quite often, the universal versions (OBJ, 3DS, etc) that the artists export are garbage because they don't fix them up after the raw export. Luckily though, as another avenue for getting this solved, Turbosquid can do a conversion for you if you open a support ticket and explain to them the problem with smoothing and UVs of the exported formats. They might try to tell you that the model is not C4D compatible, but since the artist included the OBJ and 3DS, TS support should be able to help.

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    51 minutes ago, CraigT said:

    Hey Dan - thanks for offering to try it in Modo - if that's not too much trouble, that would be fabulous! I'm always looking to learn "how" so any tips you have after looking at this file, I can use them on the other 2 models as well. I have the texture maps I've been using - let me know how you'd prefer I send these to you - hopefully we can make this model look good! :) Thanks a bunch!!!

    I need the texture maps to see what parts were supposed to be together and what parts are not.  Some parts do not occupy the full uv space.  If you select the (nose)part your see that is disjointed when you go into polygon component type, and double click on any area of the nose, some polygons will highlight while some wont as they are not joined, intentional or not if you want these seams to be gone, as bezo said use the optimize tool found in Mesh/commands/optimize.  After using this command it will perform a weld, the Uvs did not get lost.  Try this for each part but watch out for parts that were not meant to be welded.

     

    I tried to load a obj and fbx into MODO and it would not import it.  Try what I said above and that should fix the seams.

     

    Dan

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  •  

     

    Dan - I'll give the weld effort a go and will report back...

     

    Also -(Vizn) Good idea, however, I already tried them to no avail and came here for expertise help. 

     

    So - the net, net takeaway is we have an exportation issue from 3DMax to C4D (perhaps this was built in an early version fo 3DS). 

     

    As an aside - In order to minimize compatibility issues in the future, what types of things should I ask a modeling artist about their files before purchasing more models?

     

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