I tried unchecking the smooth polygons in the parameter dials. No work.

Seems like Poser hates my cylinders. The Poser Cylinder primitive prop has no flaws though.

Check the end polygons.. how many verticies do they have?

Are they UV Mapped? You might want to take them into UVMapper and give them a UV Map if they don't have one.

This look usually happens when there are too many narrow (sharp) triangles.

its not uvmapped. Is that a case?

Check the end polygons.. how many verticies do they have?

You mean the one at the center? Well, I guess its one. I didn't do any editing on these cylinders.

Quote - This look usually happens when there are too many narrow (sharp) triangles.

I'd agree with that.

To the OP: Try connecting the faces on the top of the cylinder with one line and do the same for the faces on the sides.  Try two or more if that doesn't seem to clear up the problem.

I have a nagging problem with a certain freebie I'm working on that is similar to this.  Nothing I do seems to help.  The faces coplanar, there are no unusual verts, and changing between 3/4 verts does nothing.  Even deleting the mesh in that area and rebuilding it does nothing.. I sympathize with you. It's VERY aggravating.

So, try more vertices but in another direction (Connect the tris with a line, turning some into quads.) and see what happens.

Often, polygonal primitives like your cylinder need to have some overlapping vertices welded, and that looks to be the case here.  Any time you see any irregularity in the way phong shading is applied, this is very likely the cause (non-contiguous geometry).

Or reversed normals. The winding order determines which way the normal goes, and Poser cares.

This prop has long vertical quads on the side. If they were split half way down, this would look a lot like yours.

That's a good point, although really this is a common problem with primitives exported from modelers (unwelded geometry).

Well, if the ends are n gons (polygons with more then 4 verticies, then there's your problem right here.. for poser you need to use only 3 or 4 point polygons.

If it was me, and you only needed a cylinder, why not just scale and use the included one in poser already?

Poking on this a bit more I think Bagginsbill's advice is probably on the mark, that one or more polygons has a backwards normal.  Still worth noting that primitives often have unwelded geometry though.

Quote - Well, if the ends are n gons (polygons with more then 4 verticies, then there's your problem right here.. for poser you need to use only 3 or 4 point polygons.

If it was me, and you only needed a cylinder, why not just scale and use the included one in poser already?

not quite true. you can use an N-Gon on the end of a cylinder right there without an issue. remove the center Vertex and let it be a 5-16- whatever  sided N-gon and it'll work just fine.

trust me. it'll render just fine.

erm guys?

I think we may be looking at something else here.
I just brought a cylinder in and got the same error as first shown.. on one end. now, both ends are identical in layout and vertex count, so one end having the error does not make sense.

This is a often nearly "normal" problem with more than one reason.

As first the poser render engine is optimized for curvy figures, like human or other beings. So it tries to bend all things in somewhat natural manner. In nature normally no sharp edges or really plan sides are seen.
So you get every time most difficulties trying to do straight things, e.g. buildings.

As second 4 point polygons works better than 3 point polygons. As worst as possible are narrow polygons. Multi point polygons will fail completely as I remember.

There are 2 known solutions:
Don't weld vertices at sharp edges. For example with the cylinder have three separat pieces for the top and bottom circle and the outside hull. UV mapper function split vertices.
Poser stops bending the polygons at such sharp edges. Along this edge having vertices doubled is no problem.

Other solution if split isn't usable have a second line parallel to the edge line with only a small difference.  Poser seems to use a spline function for it's bending. If having to lines nearby there isn't room enough to to have a big bend and as the bend spline is used for all connected polygons that small bend will effect to the complete area.

Though it might also be a matter of wrong normals in this case it seem not to be. The shaded parts are to regular and I can't see anything like transparence what is the fact with wrong normals.
Also if you look to the middle of the outside hull the shadows will center. I guess that hull consists of 2 polygon circles, one top polygon and one bottom polygon, right ? So we have also a small bending influence.

Quote - I tried unchecking the smooth polygons in the parameter dials. No work.

As far as smoothing is touched. The checkmark smoothing on/off and the value for smoothing angle in parameter pallet belongs together, for sure.
But they are used independently. In my test I have found that unchecking smoothing doesn't do anything to that problem if used alone. The value is used further on.
Try smooth angle 5, 10 or 20 and than uncheck the mark.
This should work lot's better but without the both solution above it will not solve that shadowing completely. Not on a really sharp edged figure. It might work best if smoothing is too much but no sharp line is needed.

Confirmed. it's happening even to completely Quadded cylinders, but only at 1 end each time.

Images follow

Just curious - when you rotate those around the central axis, does the artifact rotate, or is it just the camera vewing angle?

the artifact keeps it's position on each cylinder.. it's not display based if that's the thinking...

same cylinder OBJ imported twice, one rotated 90 degrees and moved over to 1 side to allow it to be seen.

Looks like you have a single vertex normal that is wrong. Not the whole polygon, just that one vertex.

Try exporting without normals. Poser doesn't need them and will recalculate them itself.

The only reason to actually supply vertex normals is if you want the object to be shaded like it is twisted (sort of like a bump map effect). That's how it is rendering.

now lets consider this a second. in the posting above, the cylinder is identical at both ends other than the X/Y/Z translation of points (up/down basically). no extra vertexes, faces etc. one end renders perfectly, the other has a pinching artifact.

but to correct said artifact I microbeveled the affected end as shown.  the other (top) side is unchanged.

there be a glitch in the code here.. how do we file a bug report to SM?

Quote - Looks like you have a single vertex normal that is wrong. Not the whole polygon, just that one vertex.

Try exporting without normals. Poser doesn't need them and will recalculate them itself.

The only reason to actually supply vertex normals is if you want the object to be shaded like it is twisted (sort of like a bump map effect). That's how it is rendering.

removing the normals had no effect. the artifact remains as shown.

MagnusGreel: The problem is a mesh error before export - optimise the mesh and disconnect the end caps before export and it will be fine.

Quote - I don't think this is any kind of glitch or bug, I think this is just the topology of the cylinder being exported.  You'll find that if the caps of the cylinder are modeled such that you avoid vertices that share more than or less than 4 edges on that corner, it will display correctly in Poser.

want to check my findings? I can post the OBJs to you. one has NO N-gons or tri's at all. just Quads as shown and has the artifact at one end only.

Quote - MagnusGreel: The problem is a mesh error before export - optimise the mesh and disconnect the end caps before export and it will be fine.

you sir are missing the point.

go back and read my posts. all of them. including the ones where I point out ONE END IS PERFECT THE OTHER IS NOT.

now. please explain that. by your reckoning BOTH ENDS WOULD BE AFFECTED AND NEED THE CAPS DISCONNECTING.

MagnusGreel: I read all the posts before I made my valid reply - fix the problem before exporting the mesh and it will be fine in Poser.

Quote - want to check my findings? I can post the OBJs to you. one has NO N-gons or tri's at all. just Quads as shown and has the artifact at one end only.

I didn't say anything about N-gons or triangles, in the example I gave I had tris and it displays correctly.  Since you fixed your own example with a bevel, it should be pretty clear that the way Poser displays phong shading (default 80 degrees) is looking at your geometry, seeing some angles that are less than 80 degrees, and applying phong shading to them in ways that you don't expect (or vice versa).

sorry for the caps. I wanted to emphasise that point. both ends should be affected but only 1 is. I can reproduce this easily,

my test OBj's have been into UVmapper, trueSpace, Silo, Hexagon. no errors, and the OBJ's exported from each show the SAME error in Poser.

Quote - ... ONE END IS PERFECT THE OTHER IS NOT.

Actually in your examples, both caps are displaying irregular phong shading, just the top side is not quite as obvious as the bottom problem.

Quote - > Quote - want to check my findings? I can post the OBJs to you. one has NO N-gons or tri's at all. just Quads as shown and has the artifact at one end only.

I didn't say anything about N-gons or triangles, in the example I gave I had tris and it displays correctly.  Since you fixed your own example with a bevel, it should be pretty clear that the way Poser displays phong shading (default 80 degrees) is looking at your geometry, seeing some angles that are less than 80 degrees, and applying phong shading to them in ways that you don't expect (or vice versa).

the OTHER end has not been beveled. but shows no sign of the error. please explain that.

Quote - > Quote - ... ONE END IS PERFECT THE OTHER IS NOT.

Actually in your examples, both caps are displaying irregular phong shading, just the top side is not quite as obvious as the bottom problem.

want the OBJ? no it has no error. sorry.

is it always a cause of head meet wall round here?

What's provoking all this rudeness?

sorry. got the OBJ here, eyes recently tested, not seeing it.

I'll just file a bug report... it's easier than arguing in circles for hours.

End file.

pjz99: You are quite right - the error is at both ends but one end looks better because of the viewing angle/lighting.

MagnusGreel: Can I have the .Obj file please?

The problem looks related to skewed normals on the offending polygons - in your 3d software display the normals as lines, and check they are at 90 degrees to the polygon surface.

Quote - MagnusGreel: Can I have the .Obj file please?

The problem looks related to skewed normals on the offending polygons - in your 3d software display the normals as lines, and check they are at 90 degrees to the polygon surface.

Those should be stripped on export.  Poser doesn't use normals for anything other than screwing up objects. :)

Morkonan: I just made a simple cylinder like the one posted here. Exported it from Cinema 4d with normals and it renders fine in Poser 4, 5 & 6 without shading errors, If the normals are good they shouldn't cause problems with Poser. For complex models though, they add a good bit to file size.

Quote - I'll just file a bug report... it's easier than arguing in circles for hours.

Huh, that will make SM sleepness nights ... :sneaky:

But b.t.w. has someone experience with bug reports ... where to send them and are these useful or is it only something for the files. Is a reply given if done ?

I ask cause I know lot's of bigger or smaller bugs in poser being there since versions. And I don't think nobody did find them or report them ... right ?

Obviously these shadow artifacts are not a bug. It's the normal behaviour of the render engines optimization to unstraight things.

Quote - Morkonan: I just made a simple cylinder like the one posted here. Exported it from Cinema 4d with normals and it renders fine in Poser 4, 5 & 6 without shading errors, If the normals are good they shouldn't cause problems with Poser. For complex models though, they add a good bit to file size.

True, there are many times you can safely leave them associated with the object.  I've done it as well.  But, there's absolutely no reason to if it is specifically done for Poser.  Leaving them a) Swells the object file size, sometimes >30% and b) has the "potential" to cause Poser problems.

Sure, it can be done.  But, there's no point in it.  I'll sometimes be in a hurry and leave them in when I am testing instead of scrubbing them out.  Most of the time, I don't have any problem at all.  But, I always end up stripping them out in the end.. unless I forget. :)

Hmm. There seems to be a sticking point around the idea that only one end is broken.

Suppose both ends are actually the same and broken, only it depends on your viewing angle. When you look at the cylinder, which is physically identical top and bottom, there is a difference. One is top, and one is bottom. If, however, you rotate the cylinder 180 degrees in x, you swap top and bottom - so if the artifact switches then it's in the mesh at one end (whatever the problem is) and if it doesn't switch, but looks different on top and bottom, then it is because the viewing angle matters in producing the artifact.

Also, the micro-bevel solution could simply be that an offending normal is now part of a tiny polygon and you don't notice the difference because it is less than a pixel wide.

But if you exported with no normals, that's a mystery.

Can I have the OBJ? I'll investigate too.

And if it's a real bug, I can post the bug with SM.If I post it, I can almost guarantee it will go straight to stewer (Stefan Werner, one of the top engineers at Poser/SM) with high priority.

Its NOT a bug.. you need to model FOR POSER, not for your modelling application.

Note pjz99's image with the cylinder with the point in the middle of the cylinder top.. that's the proper way to model a cylinder for poser rendering. Pose does NOT like ngons (faces with more then 4 points), and does not like extreme angles, or long thin polygons. Smith Micro even has that mentioned in either a tutorial or the manual somewhere.

Thats why my first question was "how many verts do the ends have?"

You need to learn to model for poser.

Quote - Its NOT a bug.. you need to model FOR POSER, not for your modelling application.

No, it certainly isn't a bug. I was wondering if anyone was going to actually read your post and take any notice of it.

This has been made far more complicated than it actually is. N-gons like those end caps MIGHT render properly in Poser, but do you really want to take the chance? The old LightWave technique that I use,  and which should be able to be applied in any half decent modeller, is to cut those end cap polys out, kill the polygons but leave the points that made up the polys, in place. You then select the points one by one and create all 4 point polys, except for the top and bottom polys, which will contain 3 points. You then paste these polys back as the end caps and Poser won't be able to mess the cylinder up, because the end cap polys are now detached from the cylinder body.
If you want to merge all the points, then all you have to do is set an appropriate smoothing angle either in your modeller or in your UV mapping software. There is no technical need for adding small bevels or using any other work arounds, except of course that bevelled edges always look better.

There are a couple of big caveats to that technique: unwelded geometry will fall apart in dynamic cloth simulation, and also rendering with Smooth Polygons enabled will often cause gaps to appear in non-contiguous geometry that aren't visible otherwise, e.g. in that pic I provided earlier of Poser's included cylinder primitive.  Otherwise OK though.

I model hard edged objects, so dynamic clothing is of no concern to me at all, but if you're worried about unwelded points you can weld them all and simply set smoothing angles in UV mapping software, on a surface by surface basis. It works nicely. Sometimes though, you simply have to have some unwelded points.

Not really.. and if you don't have welded verts, you can't properly use displacement maps.

Sue88 in the Maya forum also advised me to bevel the end loop and It somehow solved it. My brain couldn't process all of the data you guys have presented but I do I agree that this should somehow be reported to SM.

Its just a simple cylinder. Poser should have imported this with no problem at all.

Since nobody gave me their broken obj, I'm not going to report any problem, since my cylinder imported perfectly.

Maybe you guys should be using free software like me :)