[Help/Advice] Turbosmooth modifier problem-deformed polygon [SOLVED]

ouieer

Hello,

I've just started learning Autodesk 3D max and I'm trying to model a phone. It appears like the edges are stretching when I'm using the modifier.





Please help.

Thank you,
Elizabeth

poopipe

It'll take a lot of words to explain how to fix it exactly so I'll try to illustrate the principles. 

Pause what you're doing for the moment and make a cube. 
Apply a turbo smooth
Go under the turbo smooth and change the number of segments on the cube.  

You'll see that as the mesh becomes denser, the corners get tighter. 
Each vertex adds tension to the smoothing and gives you more control over where the surface lies. 
To get a corner to be sharp you need extra vertices near it to add tension - the lower part of your mesh doesn't have these which is why it's borked

A lot of people will now shout things like 'use quads'  and 'support loops' 
They're mostly going to be correct. 

SonicBlue

There's a reason why the material looks transparent? Have you enabled some kind of X-Ray view?

To fix this specific problem is simple, follow poopipe advice, which is add more edge loops, in these places:



You can "improve" the smoothing of the mesh by adding more edges:



You need to avoid edges that terminate into nothing, without support, the mesh will crumble into itself trying to average the distance between the points. Though, there are cases when (for example) there's a flat surface where you can leave the the edge disconnected, forming an n-gon. This causes smoothing problem when there's a difference in height between points, like in a 90° angle or simply when the mesh bend.

There's more information on the Wiki, if I may suggest something, Grant Warwick's Hard Surface Essentials video on Vimeo it's a good start.

musashidan

Welcome to sub-division modeling. This classic video is always a good place to point beginners in the very fundamentals of sub-D/topology theory

https://www.youtube.com/watch?v=k_S1INdEmdI

ouieer

poopipe said:

It'll take a lot of words to explain how to fix it exactly so I'll try to illustrate the principles. 

Pause what you're doing for the moment and make a cube. 
Apply a turbo smooth
Go under the turbo smooth and change the number of segments on the cube.  

You'll see that as the mesh becomes denser, the corners get tighter. 
Each vertex adds tension to the smoothing and gives you more control over where the surface lies. 
To get a corner to be sharp you need extra vertices near it to add tension - the lower part of your mesh doesn't have these which is why it's borked

A lot of people will now shout things like 'use quads'  and 'support loops' 
They're mostly going to be correct. 

Thank you poopipe! 

ouieer

SonicBlue said:

There's a reason why the material looks transparent? Have you enabled some kind of X-Ray view?

To fix this specific problem is simple, follow poopipe advice, which is add more edge loops, in these places:



You can "improve" the smoothing of the mesh by adding more edges:



You need to avoid edges that terminate into nothing, without support, the mesh will crumble into itself trying to average the distance between the points. Though, there are cases when (for example) there's a flat surface where you can leave the the edge disconnected, forming an n-gon. This causes smoothing problem when there's a difference in height between points, like in a 90° angle or simply when the mesh bend.

There's more information on the Wiki, if I may suggest something, Grant Warwick's Hard Surface Essentials video on Vimeo it's a good start.

Hello,

Are you using 3Dmax? I've set the object's visibility to 0,9 in its properties.
I've tried adding more edges and it works. I don't know if I'm doing it right but here are some screenshots 





Is this okay? I used the loop and cut tool.
I'll post the final render when I'm done with my model 

Kram,
Elizabeth

poopipe

Divide up the longer edges on the right as well - the corner there is stretching out quite a lot.

SonicBlue

ouieer said:

Hello,

Are you using 3Dmax? I've set the object's visibility to 0,9 in its properties.
I've tried adding more edges and it works. I don't know if I'm doing it right but here are some screenshots 





Is this okay? I used the loop and cut tool.
I'll post the final render when I'm done with my model 

Kram,
Elizabeth

No, sorry, I'm not a Max user, the basic principles works with every software though.

If you need to see through your object, but you don't want to use the wireframe view, press ALT+X, as it goes in X-Ray view.

What poopipe suggested, is to add another edge loop to the right too, if you look at the left side, the edges of the phone front camera (?) are keeping the shape together, while on the right there's more space between the various edge loops, though, while I agree that there's a need to have the shape in control with a series a of supporting edge loops, I believe that the problem you are facing is caused by the fact that right edge loop (but the left too) are not going all the way up, instead they end reaching a 90° angle from the screen cavity to the phone shell. That's why you see the edges bending at the last row of polygons, there's a missing edge and they try to compensate that.

I don't know why the edge loop stopped there in both cases, maybe there's a point somewhere, but I can't see where it may be. The algorithm for the edge loop cut doesn't like non quadrilateral polygons, so it stops cutting when it finds them. To finish the cut all the way up, you need to use the Cut tool, and manually cut the mesh.

To inspect better your mesh, thick the Isoline Display option in the TurboSmooth menu, it will only show the subdivided version of the edges you currently have, otherwise you are previewing the complete subdivided mesh and it's difficult to see what's going on as there are too many edges. Also, you can probably get it away with only 2 subdivisions (Iterations), it will be faster to work (every subdivision level increase the polycount by 4 times), when you are done you can increase it again, also there's an option where you can set a different value at render time.

There are other parts of your mesh that have partially cut geometry, you obviously need to fix them, or you won't get a clean mesh.

ouieer

SonicBlue said:

There's a reason why the material looks transparent? Have you enabled some kind of X-Ray view?

To fix this specific problem is simple, follow poopipe advice, which is add more edge loops, in these places:



You can "improve" the smoothing of the mesh by adding more edges:



You need to avoid edges that terminate into nothing, without support, the mesh will crumble into itself trying to average the distance between the points. Though, there are cases when (for example) there's a flat surface where you can leave the the edge disconnected, forming an n-gon. This causes smoothing problem when there's a difference in height between points, like in a 90° angle or simply when the mesh bend.

There's more information on the Wiki, if I may suggest something, Grant Warwick's Hard Surface Essentials video on Vimeo it's a good start.

Hey!

Are you using 3Dmax? Yes I've set the object's visibility to 0,9 in the object's properties.
Thank you, I'll check the links you provided and try adding more edges.

Thanks!

ouieer

SonicBlue said:

There's a reason why the material looks transparent? Have you enabled some kind of X-Ray view?

To fix this specific problem is simple, follow poopipe advice, which is add more edge loops, in these places:



You can "improve" the smoothing of the mesh by adding more edges:



You need to avoid edges that terminate into nothing, without support, the mesh will crumble into itself trying to average the distance between the points. Though, there are cases when (for example) there's a flat surface where you can leave the the edge disconnected, forming an n-gon. This causes smoothing problem when there's a difference in height between points, like in a 90° angle or simply when the mesh bend.

There's more information on the Wiki, if I may suggest something, Grant Warwick's Hard Surface Essentials video on Vimeo it's a good start.

Hey!

Are you using 3Dmax? Yes I've set the object's visibility to 0,9 in the object's properties.
Thank you, I'll check the links you provided and try adding more edges.

Thanks!

ouieer

SonicBlue said:

ouieer said:

Hello,

Are you using 3Dmax? I've set the object's visibility to 0,9 in its properties.
I've tried adding more edges and it works. I don't know if I'm doing it right but here are some screenshots 





Is this okay? I used the loop and cut tool.
I'll post the final render when I'm done with my model 

Kram,
Elizabeth

No, sorry, I'm not a Max user, the basic principles works with every software though.

If you need to see through your object, but you don't want to use the wireframe view, press ALT+X, as it goes in X-Ray view.

What poopipe suggested, is to add another edge loop to the right too, if you look at the left side, the edges of the phone front camera (?) are keeping the shape together, while on the right there's more space between the various edge loops, though, while I agree that there's a need to have the shape in control with a series a of supporting edge loops, I believe that the problem you are facing is caused by the fact that right edge loop (but the left too) are not going all the way up, instead they end reaching a 90° angle from the screen cavity to the phone shell. That's why you see the edges bending at the last row of polygons, there's a missing edge and they try to compensate that.

I don't know why the edge loop stopped there in both cases, maybe there's a point somewhere, but I can't see where it may be. The algorithm for the edge loop cut doesn't like non quadrilateral polygons, so it stops cutting when it finds them. To finish the cut all the way up, you need to use the Cut tool, and manually cut the mesh.

To inspect better your mesh, thick the Isoline Display option in the TurboSmooth menu, it will only show the subdivided version of the edges you currently have, otherwise you are previewing the complete subdivided mesh and it's difficult to see what's going on as there are too many edges. Also, you can probably get it away with only 2 subdivisions (Iterations), it will be faster to work (every subdivision level increase the polycount by 4 times), when you are done you can increase it again, also there's an option where you can set a different value at render time.

There are other parts of your mesh that have partially cut geometry, you obviously need to fix them, or you won't get a clean mesh.

Good evening!

I've done as instructed and check this out!







Wow I'm surprised that I could do this !!! Really happy that I signed up here to get help. Now I'm just left with the cameras alignment and more edges on the speakers. 

Thank you so much for helping me with this activity! @sonicblue & @poopipe

Kram,
Elizabeth

SonicBlue

Yeah, but now the mesh is less clean and subdividing it creates a mess, because there are overlapping edges in the same spot and other edge cuts where they shouldn't be.

The edges highlighted in orange are the one that causes the most problem, for the speaker, on the left side there's only one edge visible (even if it's clear that there are more, by looking at how thick the line is) but when you subdivide it, 3 appears, same thing on the right side there are 2, but then, 4 show up.

You should remove them, using the subdivided mode to see them clearly, I believe that you can select them and use CTRL+BACKSPACE which should prevent the face to be deleted as well.

The blue lines will help support better the shape.

ouieer

SonicBlue said:

Yeah, but now the mesh is less clean and subdividing it creates a mess, because there are overlapping edges in the same spot and other edge cuts where they shouldn't be.

The edges highlighted in orange are the one that causes the most problem, for the speaker, on the left side there's only one edge visible (even if it's clear that there are more, by looking at how thick the line is) but when you subdivide it, 3 appears, same thing on the right side there are 2, but then, 4 show up.

You should remove them, using the subdivided mode to see them clearly, I believe that you can select them and use CTRL+BACKSPACE which should prevent the face to be deleted as well.

The blue lines will help support better the shape.

I cleaned up the model but I'm not sure if I deleted the exact edges.

SonicBlue

It's starting to look good.

Now, for the final part, if you want to clean up the mesh a little more:

I've removed the two edges that are superfluous, you just need to keep the central one and you'll get a better shape.

Since it's a curved shape, it's better to compare the result with a circle to get an idea of how the shape really looks. I've added more supporting edges to keep the shape as a perfect circle as possible and I've also tightened the edge loop that surrounds the speaker hole (in the two previous picture is at a distance similar to yours). The edges needs to be straightened better in my example, but it should work.

There's also the hole for the camera to fix.

ouieer

Hello!

After removing the extra edges and adding the same edge you did, the shape of the speaker has changed enormously.





I don't understand what I'm doing wrong (

Kram,
Elizabeth

SonicBlue

Probably you have to slide the outer edge, it's too far away, then you have to move the edge loops to make them straight

Compare it with the subdivided version I've posted earlier.

ouieer

Hi!

Sorry for the late reply. I've been busy studying for my exam!

Check this out...

--------------------------------------
with single edge



--------------------------------------
With double edge





Why is it doing that?

Mvh,
Elizabeth

musashidan

Easiest method is to just add more segments to the circular shape. It will represent the curve almost perfectly circular when subdivided.

In your last image it's doing that because tight loop you added is averaging towards the curve, which results in an uneven subdivision spacing, which can be seen clearly in the isoline display.

cylinder/box to show how closely the mesh retains its form after subdivision

cage mesh with extra circular segments

SonicBlue

Well, I don't know how much you can translate with 1:1 topology, considering that Max uses an algorithm called NURMS and Blender Catmull-Clark, or the straightened edges can cause problem, anyway:

In this case, they both work good, maybe try to pull your edge loop more distant from the semicircle.

To get the shape as close as possible (on both sides) you need to move and scale some parts, to be specific, these points highlighted (but not only, use your eyes to judge)

|| I could have matched it better if the coloured wireframes were not taboo, the splines are terrible too ||

Though, it seems that the non straightened part (left) works better.

ouieer

https://www.youtube.com/watch?v=eDeWs5E-qjI



I think I managed to make it more rounder by moving edges but I'm not sure if I've done the proper way. Please check out the video.

Thanks!
Elizabeth

SonicBlue

Definitely easier than the method I suggested, the result looks pretty accurate.