Slight problem

[Phil Deakins]

If you've seen my recent posts here, you'll know that I am a complete noob as far as mesh is concerned. I've been using Gaia's tutorials and I'm making (slow) progress. But I've come to an impasse.

I'm trying to make a quarter cylinder but I'm using Blender 2.76 - downloaded a few days ago. When Gaia uses a cyclinder in the Coffee Cup tutorials, she uses an older version of Blender and the cylinder ends each had a central vertex with edges to all the outer vertices. But 2.76 doesn't do that. The cyclinder ends are closed, with no vertices in them at all.

I can remove the faces and edges around 3/4 of the cylinder, and I'm left with the quarter curve that I want, BUT I'm also left with no sides to the quarter cylinder, and without the central vertex, I don't know how to get them. I tried triangulating a new cylinder to see of that put a vertex in the centre of the ends, but the ends are sliced up without a centre vertex.

I'd very much appreciate it if someone could tell me either how to add a vertex where I need it to be, or how to remove 3/4 of the faces around the cylinder but keep the 1/4 sides. Or any other way of making a quarter cylinder with sides shape. Starting with a cylinder is ideal though, because it smooths beautifully to a curve.

[Pamela Galli]

Phil as soon as you add a cylindar, look down at the bottom left corner, at the bottom of the Tools shelf, and change Ngon to Fan:

 

https://www.dropbox.com/s/25rnfyxfx2wwnyg/Screenshot%202016-01-27%2009.06.17.png?dl=0

 

Oh, if you hit 1 to align your view straight on, then click Align to View in that same shelf area. 

 

To make the missing sides, select the top edge and the bottom edge and press the F key.

But if this is for your headboard, you dont want sides. Duplicate the quarter cylindar while in Edit and rotate it to make the other corner. Then select the edges you want to connect with F (Or you can use the Bridge tool.)

Then you would extrude the bottom edges down to make the rest of the bedframe.

 

https://www.dropbox.com/s/imdmd0tf881xuzz/Screenshot%202016-01-27%2009.20.22.png?dl=0

 

 

 

[Phil Deakins]

Thank you Pamela.

First quick reply before I look at the main part of your post:-

It is for the headboard, and being totally new to mesh, the way I'm doing it is in 4 parts, 2 of which are the top ends, which are curved. I did think of doing it with a cube, flattening and stratching it, and rounding the top corners, but I'm brand new at this and I'm making headway very slowly indeed

Now I'll look at the main part of what you wrote.

ETA: Aha! Fan did it

[Gaia Clary]

Hi;

I am not sure if i understand your issue correctly. But here is some information that hopefully helps you to figure out your problem:

When Creating a new Object



 

1. Take care that your Selection Mode is set to "Face" Before you add a new Cylinder. Then you see the cylinder caps are NGons. This setting is not strictly necessary. See in the image above, there you just cant grab the cap face. But you can switch to face selection mode at any time, so nothing is lost
2. Right after you added a new Object (Cylinder) then you get an Operator Redo panel in the left lower corner of the Tool Shelf. In our case the redo panel is titled: "Add Cylinder" Here you can tweak the initial settings of your object. This is a bit odd first. But you can think of your new object to be in its "childhood" and it still can be formed to some extend.
3. Right in the middle of the Operator Redo Panel you find the setting for the Cylinder Caps (the Cap Fill Type). There you can select to have no caps at all.

When you go ahead from here and call any other operation on your object, then the Redo Panel will be replaced by the redo panel for the next called operation (if that operation has a redo panel)

Adding a connected Vertex to an existing Object

You can add vertices as follows:

 

1. Select your active vertex (use the Right mouse button) This indicates the root of your editing
2. CTRL LMB (control on the keyboard and Left Mouse Button) adds a new vertex to your  scene. The new vertex is connected to the previous active vertex. the new vertex is now the new active vertex

So you can add a loop (set of vertices connected by edges) by repeatedly pressing the left mouse button while you keep the CTRL key pressed

Adding an edge

Do the same as for the Vertex, but use Edge Select mode (see image). Then select your active edge. When you now CTRL LMB then you get a new edge  and the edge is connected to the formerly active edge (similar to above)

Adding a face

Do the same as for the Vertex, but use Face Select mode (see image). Then select your active Face. When you now CTRL LMB then you get a new Face and the face is connected to the formerly active face (similar to above)

 

[Pamela Galli]

This is a good project for learning basic stuff like rotating, extruding etc.

 

The cube way is probably a little easier but either will work. YOu would need to add edge loops so you could move vertices to make the curves. Always more than one way to skin a cat in Blender. 

 

 

https://www.dropbox.com/s/3rml21z21uq3ncg/Screenshot%202016-01-27%2009.43.06.png?dl=0

 

BTW, if you need to know how to, for example, extrude, just Google Blender Extrude and you will probably find tutorials focusing on just that one very handy skill.

 

[Phil Deakins]

Thank you ladies

After using Gaia's instructions on adding vertices etc., for which I thank you, Gaia, and after trying (experimentally) Pamela's suggestion of just using a cube, and getting nowhere very fast, I went back to using cylinders for the top corners, and selecting that 'Fan' option. And I made what I'm after

But it's not finished yet. First I though that smooth would be good, even though I'd already smoothed those corners. Not good. So I made it flat again, which is good. Now I need to go through Gaia's texturing tutorials because, unlike a sculptie, that can take a texture and you can set the repeats you want, this bedhead object doesn't like me setting repeats. No matter what I do, it's as though the texture scales are permanently 0.

ETA: I almost forgot. I remember making rounded cirners when briefly played with sculpties some years ago, and I don't fancy manually setting the vertices at just the places, so I didn't pursue it too much.

[Pamela Galli]

Even with the simplest things, there are a lot of things to learn. Like about smooth vs flat, for example. It may seem an insane amount of time making some simple thing, or it did/does to me, but it does prepare you for the next thing.

 

So yes, UV mapping -- like laying out a dress pattern -- is next.  Then you can add your texture inworld and it will go the right direction and have the right scale.

[Phil Deakins]

Mistakes are possibly the best way to learn something - like that smooth/flat thing.

And there is no substitute for time spent doing it. Yes, you are right, Pamela - it does seem like an awful lot of time to make one very simple object, and I do confess to thinking more than once how few minutes it would have taken one of you experienced people to do it, but throughout all that time, I've been absorbing bits of how to operate Blender, so none of it is wasted.

I'll leave the UV mapping for tomorrow, but i do want to add that I have no intention of laying out a dress pattern either next or at any time in the future lol.

 

[Drongle McMahon]

Just to illustrate your point, here is another way of making it, and something about getting the shading right.

1. Scale your cube to 3.0  x 0.1 x 0.6.

2. Select the short upper corner edges.

3. Do Mesh-Edges->Bevel; setting amount to 0.3 and segments to 6, in the toolbox.

4. (Matcap shading to see effects). Now we have faceted edges from flat shading.

5. Set whole object (Object more) to Smooth shading -> unwanted smnooth shading of front.

6. Add the modifier "Edge Split", with default settings -. Now the rounded edge is smooth, but the rest are sharp.

7. Looking at the result in object mode, but perfectly sharp edges are not ver realistic.

8. Next lesson will be ways to make smooth edges that give proper edge highlights (two ways).



Note "8" is the step that is often left out. It's one reason why people think advanced lighting and materials don't work, because they don't see expected highlights. Slightly smoothed edges are essential for realistic edge highlights with advanced lighting and material.

[Phil Deakins]

That looks very quick 'n' easy, Drongle, and I greatly appreciate the effort you put in the produce the post with images. I was steaming along merrily, right up until part way through step 3. Not very far lol

No matter what I do, I can't reproduce the curves that you made. The curves I get are elongated, starting a fair way along the top and ending at a much shorter distance down the sides. I set everything right - amount 0.3 and 6 segments - and I got the curve starting at about 1/5 of the distance along the top, and ending at a similar fraction of the distance down. I've just tested it by eye, by making the object a square instead of a rectangle, and the fraction of length along the top is the same a the fraction of length down the side.

I fiddled in the toolbox, trying the vaious Amount Types, various Amounts, and various Profile numbers, but I couldn't get it to produce anything other than the same elongated curve. I do like the simplicity of the way you did it, compared to the way I did it, and I'd really like to do it your way, but I can only produce elongated curves on the rectangle. Reminder: I'm using Blender 2.76.

[Drongle McMahon]

I think you must have scaled the cube in Object mode. If you do that, you need to do Object->Apply->Rotation & Scale before you edit in Edit mode. This is because the bevel is applied to the object before the Object-mode scaling. So the bevel gets scaled too. Lots of tools work that way. So it's (nearly) always best either to avoid scaling and rotation in Object mode, or to remember to Apply them. If you do the scaling in Edit mode after selecting everything, you will avoid this, and many similar problems.

[Phil Deakins]

Thank you, once again, Drongle. I couldn't find anywhere to type in the object's dimension in Edit Mode, and it was awkward using the mouse and watching the numbers, so I still did it Object Mode, and did the Apply thing, which worked perfectly.

I got stuck at the modifier Edge Split though. I couldn't find the modifiers as such. I searched the Web, and read the relevant parts in the current Blender's manual, but still things didn't seem to be as they were described; i.e. no place to put values or use the default ones. No values at all, in fact. I did find Edge Split under Mesh -> Edges but it didn't seem to do anything, and still no place for values appeared. Nevertheless, I flattented the relevant faces by selecting them and flattening them, which appears to have had the same effect.

I'm writing this before I upload it, but it looks ok. I expect that textures will still need to be dealt with, as some of the faces on the versions I've uploaded so far have textures in different direction according to the traingles. Oddly, though, some faces have both their triangle's textures matched in direction. Maybe I'll understand why some and not others one day.

All of this is excellent. All the searching, trying, etc. etc., is adding to my knowledge and practise in using Blender for meshes. To be honest, although it's taking me much more time than experienced people would need, the time spent searching in Blender and on the Web, following instructions, getting things wrong, etc. is invaluable for me - and I know you've all gone through it

[Pamela Galli]

I still make things very very slowly, and often come crying to this forum for help. Without the helpers I have met here, and one who became my mentor, I would still be trying to make my first object.

[Drongle McMahon]

To add Edge Split modifier (and others) ...

Select object (either Object or Edit mode). The Object Properties panel is usually on the right. If it's not there, (make a window for it and) set the window type to Properties by choosing the icon shown at (1). Now click the spanner/wrench icon (2). This reveals the Add Modifier button (3), which will yield the list of available modifiers, wherein you can click the Edge Split item (4). The newly added modifier will appear in the modifier stack, with widgets to set its parameters (5).



 

[Drongle McMahon]

"I couldn't find anywhere to type in the object's dimension in Edit Mode"

I don't think there is anywhere. You can select a face parallel to an axis and move it by typing in the sppropriate. Transform Location coordinate. I did the scaling in edit mode in the knowledge that the default cube is 2 x 2 x 2. So I just selected all and then typed 'SX1.5', 'SY0.05', 'SZ0.3'. It's a pity there isn't an Add->Cuboid, with a toolbox allowing you to type all three dimensions independently.

Ah! There is, although it isn't called cuboid. Just do Add->Round Cube->Custom; leave Arc at 1 and type in dimensions.

Experiment is the key to Blender knowledge.

[Phil Deakins]

I can fully understand that, Pamela. There's an awful to learn with Blender.

[Phil Deakins]

Done it, Drongle. I would never have found the spanner. I might have stumbled into it way down the line. In my searches, there was nothing about it, not in the manual parts that read, or on any webpages that I found. It's probably mentioned somewhere but I certainly didn't come across it.

I don't have Round Cube in the Add pop-up, but it's ok. Doing it the Apply way is very quick and easy. I will no doubt have forgotten exactly how it done if and when I need it again, but that's ok too. I have all the posts in this htread in my emails.

Thank you for all your help. That goes for everyone in the thread.

 

[Drongle McMahon]

I can't remember where the Round Cube came from. Maybe you can activate it in User Preferences/Addons? It's nice. There are some structures for which the sphere with cube-based mesh is much better than a UV sphere or ico sphere. Other variations, capsule etc, are also very useful.

[Drongle McMahon]

Here are some ways of getting the edge highlights.



On the left is a picture from Blender. At the top is the headboard with the edge split modifier. 

Next is the same model set to smooth shading, but with Auto Smooth switched on and its angle set to 87 degrees (Little triangle next to spanner = Object Data; Normal section at the top). This achieves the same effect as the edge split, but beware, the altered normals produced by Auto Smooth are NOT exported (yet). So in SL, this will look just like the wholly smooth shaded mesh.

In the third model, the edges where we need highlights have been smoothed by adding a very narrow two-segment bevel, with the Profile set at 1.00 to keep the adjoining faces completely flat (Bevel parameters Amount=0.015, Segments=2, Profile=1.00). You can see the highlights along the smoothed edges (thanks to Matcap). However, there is an unwanted darkening along the bottom and back edges. This is where the shading conflicts with the sharp edges left by the 1.00 profile.

The darkening can be reduced by using a real bevel with just one segment, but to keep the adjoining faces flat, we now have to use edited vertex normals along the bevelled edges. This is done by using the Data Transfer modifier to transfer the normals from the auto-smoothed model (details below). Now we still have the desirable edge highlights, but little or no darkening artefact is visible along the bottom edges.

On the right are the models inworld. The auto-smoothed one is not there because the altered normals are not exported. However, you can see that the normals transferred by the data transfer modifiers are exported. So all the effects on the shading of the edges of these three models do appear inworld too. At the bottom is another way of obtaining the edge highlights. This is the edgesplit model, but with a normal map baked from the bevels2p1 model. Note that these have blank texture. The shading and highlights are solely from the inworld lighting, here with default 3pm daylight only, no local lights.

Both the bevel methods add a lot of geometry, and this does increase the download weight. For this simple model, using the edgesplit model for medium and low LODs, and a simple model for lowest LOD and physics, the download weights are 0.1 for the edgesplit model and 0.4 for either bevelled model. All those end up with LI=1, but with more complex models, you can expect to pay for the improved highlighting with an LI penalty. In contrast, the normal map approach doesn't cost any LI, but does require an extra texture, unless you are already using a normal map, in which case it's free. The single bevel with edited normals does have one more advantage over either the double bevel or the normal map models. Because it does have a real bevel in the geometry, in close up views of the silhouette there is less obvious conflict between shading and outline.

Here are some details of the vertex normals. The two at the right are the single-segment bevel model before and after adding the data transfer modifier.



And here is the data transfer modifier. The parameters changed from default are shown by the yellow rectangles. Note the it is essential that the origins of the source and destination meshes must be in exactly the same place for this to work. In his case, that is easily satisfied because they are duplicates of the same original mesh.



ETA:Two important things I forgot to mention!

Note 1) With the two bevelled models, it is essential that you do upload with the edgesplit model for the lower LODs. If you rely on the auto-generated LODs, loss of the geometry and/or edited normals will cause the smooth shading to flow into the flat faces, causing an abrupt and unpleasant change in shading when the LOD switches.

Note 2) When you export a model with transferred normals, you need to uncheck the Triangulate option in the collad export options panel. This is because any change in geometry, including triangulation, disrupts the custom normals, For the same reason, you must only add the data transfer modifier after you have completed all changes to the geometry.

 

[Phil Deakins]

Thank you again for all the information, Drongle. I have it all in emails, in a mesh folder, so that I can quickly refer to it as needed - better than searching for this thread after a while