Blender - Making Precise Selections

8/13/2019 Blender - Making Precise Selections

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4aMaking Precise Selections

In 3D, making any model from futurisc cies to prehistoric dinosaurs requires

that you have good control of the verces, edges and faces. This bonus material

oers some more in-depth training on using them.

You will learn about the following topics:

Analyzing and xing modeling problems

Meeng Blender's ocial mascot Suzanne, and then stretching and bending her

Grouping verces to make modeling easier


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Introducing Suzanne

You may have noced that we skipped over the Monkey in Chapter 4, Modeling with

Verces, Edges, and Faces. The monkey, as shown in the following screenshot, is named

Suzanne. The monkey really isnt a geometric solid like the other shapes, but it is very

special to the Blender community.

Suzanne is actually a chimpanzee, not a monkey, and she was named aer Suzanne the

orangutan in the movieJayandSilentBobStrikeBack. She is oen used for tesng materials,

animaon, lighng, and almost anything you want to do. In this way, she is Blender's versionof the UtahTeapotthat is seen in the next image. The Teapot was made in 1975, at the

University of Utah, to test out things, such as mapping, texturing, and shadows, and has

been seen in ToyStory, TheSimpsons,and many other animaons.


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Blender users tend to be a bit irreverent, so there have been a number of variaons of her,

including aliens and the three-eyed monsters. Now, you are going to join this tradion, and

do some hideous and unnatural experiments on her.

For your reference, the le 6907_04_makinga basicobject.

blend, which has been included in the download pack, has Suzanne all

ready for her close up. This is the same as your Suzanne1.blendle.

Making precise selections

While the tools you have studied are a great start, when you are making detailed models,

somemes picking verces is a challenge. So, here are some more techniques to help you.

Time for action making back-facing geometry accessible

When you are using the Texture or Solid shading, Blender lets you control whether you can

see and modify verces, edges, and faces that point away from you. This can be a help or a

hindrance depending on what you are doing. So, it's good to be able to have it set the way

you want it.

1. Press the Tabkey to get into EditMode.

2. PressAto deselect all the verces.

3. Press Band move the LMBto use the border selecon tool, to select all of the

verces. Don't rotate the view, you just want to select from the front.

4. PressX. A menu pops up. Select Verces.

5. Press the MMB, and rotate the view, so that you can see Suzanne from the side.


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What just happened?Good queson. You selected all the verces, and then deleted the selected verces. So, why

is anything le? As it turns out, as you can see in the following image that when you view thescene in the Solid mode, the faces, edges, and verces that cannot be seen are hidden, so

that they can't be selected. Let's do something about it.

Time for action controlling the visibility of vertices

As horrible as this looks, it's not bad. Only selecng the visible verces gives you one way to

control the verces you are working on. It's a tool, but it's no good unless you have control.

1. Press Ctrl+Zto undo deleng Suzanne's verces.

2. Press Numpad 1to select the FrontView.

3. Now look on the 3D View header. There is a buon that controls the visibility of

the hidden and back-facing verces, edges, and faces. It is seen on the right of the

following illustraon. It is just to the right of the three buons that control whether

you are working on verces, edges, or faces. Click the LMBon it, so that it turns light

grey. You'll noce that you can see more edges within Suzanne.


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5. Use the border selecon tool to select all of the verces.

6. PressX. A menu pops up. Select Verces.

What just happened?Okay, everything worked as expected. You selected all the verces, deleted them, and

everything disappeared. This me, the hidden, back-facing, and the front-facing verces

were selected. Controlling whether you display the hidden and back-facing verces can save

you me in making your selecons. It's good to know about it, just in case you nd yourself

wondering why some verces aren't geng selected. You can check to see if that buon

is set improperly.

Time for action selecting vertex by vertexWhile most of the me you can select the verces you need with just a couple of border

selecons and a circle selecon, somemes you need a parcular vertex or verces. The

same rules apply to selecng individual objects, verces, edges, or faces.

1. Press Ctrl+Zto undo deleng Suzanne's verces.


3. Move the cursor over one of Suzanne's verces. Click the RMBto select one vertex.

4. Now, hold down the Shikey, and select the other verces with the RMB.

5. While holding down the Shikey, select a vertex that you have already selected.

What just happened?This is probably the simplest way to select verces, edges, and faces. It is also the most

laborious, since you can only choose one at a me. But, if you use the other methods to

select the majority of verces and nish o with vertex by vertex selecon, it gives you the

best control. Clicking on an already selected vertex deselects it.

Time for action ne tuning the Circle selection tool

You can adjust the size of the circle to tailor it to your needs. You can use the +and signs on

the Numpad. If you are emulang the Numpad, you will have to do this with a mouse wheel.

1. Press Cto acvate the Circle selecon tool.

2. Select some of the verces.


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3. Now, press the +(plus) sign on the Numpad several mes.

4. Select more verces.

5. Now, press the (minus) sign on the Numpad several mes.

6. Select more verces.

7. If you have a mouse wheel, roll it forwards and select more verces. Roll it

backwards and select more verces.

8. Press the RMBor Esckey when you are nished selecng.

What just happened?That's right. You can adjust the size of the Circle selecon tool. When you make it ny, you

can work in almost as detailed a way with the Circle selecon tool as with the vertex by

vertex RMB selecon method. Since you can drag the mouse when using the Circle selecon,

you can work faster. You can increase the size of the circle to enormous and select a lot of

verces at once, such as the Border selecon, making it a very exible tool. If you have a

mouse wheel, you can use it to make the circle larger or smaller, while selecng.

Time for action hiding the vertices you aren't working on

One of the keys to working with a complex object is hiding the verces that you don't want

to work with. In this way, it makes things simpler visually, and you don't select the wrong

verces by accident.


2. Select some of the verces using whatever commands you want.

3. Press H.

4. Select some more verces.

5. Press G, thenX, and move the cursor to move your selected verces inX.

6. PressAlt+H.

7. Press Shi+H.

8. PressAlt+H.


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What just happened?You selected some of the verces. Then, you hid the selected verces by pressing the Hkey.

You selected more verces, and moved them. Then, you unhid the hidden verces with theAlt+Hcommand.

Despite the fact that the verces had been selected prior to being hidden, they were not

aected when you selected more verces and moved them. So, Blender does not move

the hidden verces.

Then, you pressed Shi+H, which hid all verces that are not selected. When you pressed

Alt+Hagain, they reappeared. Hidden verces that are redisplayed with Shi+Hare displayed

as selected verces. These commands work not only with edges, faces, and verces, but also

with complete objects.

Time for action modifying objects made by other peopleAs great a modeler as anyone can be, no one has the me to make all the models they use.

So, somemes, you will use a model that someone else has made. Somemes, you will need

to go in and make minor changes. This exercise will also give you a chance to pracce your

selecon skills.

1. Press Ctrl+Zunl Suzanne is whole again, and the verces that you moved are back

in their original places. PressAto deselect all the verces.

2. Zoom in to Suzanne's right eye (on your le). Keep the front view.

3. Make sure that you can see the hidden verces by toggling the visibility selecon

buon on the 3D View header.

4. Select the verces of Suzanne's right eye using the Circle tool. Note that, as in the

image seen here, the eyes extend beyond the sockets. Do not select the verces

from her skin. Remember that if you have to shi the view within the 3D View while

you are selecng, press Escor the RMBto stop the selecon. Then, adjust the view

with Shi+MMBor Ctrl+MMB, and press Cagain to connue selecng.


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5. Be very careful in which verces you select. Suzanne's eyes have eight sides; it's like

a spider web. Don't select any verces that aren't part of this paern.

6. Are you sure you got them all, and only the verces of the eye? Zoom in and look

very closely.

7. Another way you can test this is by moving the verces you have selected, and see if

there are any surprises. Press Numpad3to get a side view. Press Gthen Y, and drag

the verces with the cursor.

8. Press the RMBto return the verces to their original posion.

What just happened?

Well, you carefully selected just the verces in the eight-sided paern of the eye. Then, youzoomed in to double-check your work. When you tested this by moving the eye in Y, the eye

should have moved without bringing any of her face with it. But, it appears as though some

of the face has come too, as you can see in the previous image. I have two theories about

what is wrong. I think that it could be either that the faces of the eye and the skin share

a vertex, or there are two verces in exactly the same place. Now, you have to gure out

exactly what the problem is, and resolve it, which is what we will do next.

For your reference, the le 6907_04_practical modeling1.

blend, which has been included in the download pack, has

Suzanne with her eye verces selected. 6907_04_practical

modeling2.blendhas the eye pulled out with the skin aached.


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Time for action xing Suzanne's eye

Small mistakes happen to the best of modelers. It's good to know how to look at the le, andgure out what the problem is, so that you can modify the object and x the problem.

1. Save a copy of the Suzanne le using the SaveAscommand in the Filemenu, but

increment it, as you learned in the previous chapter, so that you have the original

and a copy that is at the current state. This is just to preserve your work, in case you

need to go back.

2. The rst thing to check is whether there are two verces in the same locaon.

3. Press Gthen Y, and move the eye out in front of Suzanne's face again. While you

move it, press the Ctrlbuon. Make sure that it is far enough in front of her face

that the eye does not overlap her skin at all. This me, press the LMBto drop

it there.


5. Using the vertex select, click on the RMBseveral mes on the vertex that seems

to be in both the eye and the skin. Do you see changes similar to the ones shown

in the two images here?

6. As you can see in this image, you seem to have selected a single vertex, but the

highlighted edges extending from it seem to go in two dierent paerns. One

selects edges for the eye as on the le, one selects edges for the skin as on the

right. So, it appears that there are two verces in the same place.

7. Keep selecng that vertex ll you have selected the one that connects to edges on

the skin, as seen in the previous right-side image.


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8. Next, rotate your view so that you are looking up at Suzanne from the lower-right,

as shown in the following screenshot:

9. Press G, then Y, and move the vertex towards the face unl the rim around her eyeis prey much even, as seen on the right. While you are moving the eye, experiment

with holding down the Shibuon, or the Ctrland Shibuons. The Shibuon

will cause the vertex to move slower, The Shi+Ctrlbuons will cause it to move in

increments of 0.1.

10.Click the LMBto drop the vertex in that locaon.

11. Press Numpad3to switch to the side view again.

12. PressAto deselect all the verces. Select all the verces of the eye. Press G, then Y

to move them. Press the Ctrlbuon while you are moving them. Move them ll they

are even with the verces of the other eye.

13.Click the LMBto drop them in place. You may want to zoom in for the

nal placement.

What just happened?Well, you found that even the pros goof once in a while, so a mistake is no big deal. You

learned how to analyze a problem with a model, and make correcons to it. Well done!

You wisely saved a back-up copy of your le, just in case things went wrong during the repair.

Next, you moved the eye along the Y axis to invesgate why the skin and the eye were stuck

together. Since you pressed the Ctrlkey while you moved the eye, it moved in increments

of 1. So, moving it back into place later on was easy.


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By clicking on the vertex a number of mes, and nong that the highlighted edges that

radiate out changed, you discovered that there were two verces in the same place. If there

had only been one vertex, which was used by both the eye and the skin, then the edges

would not have changed in appearance as you connued to click.

Knowing what was wrong, you were then able to select the skin's vertex, and move it back

into place. While you were doing that, you discovered some more ways to control the

moon of the cube with smooth increments, while you move it.

Finally, you moved the eye back in place, by aligning it with the other eye. Since you used the

Ctrlkey when moving the eye, it fell back right into it's original place. If you have any other

irregularies that happen during modeling, I know that you'll gure out how to x them.

For your reference, the le 6907_04_untangling suzannes

eye1.blend, which has been included in the download pack, has

Suzanne with her eye vertex selected. 6907_04_untanglingsuzannes eye2.blendhas Suzanne with the skin vertex

selected. 6907_04_untangling suzannes eye3.blend

has the skin vertex being moved back into place.

Organizing your work by grouping

Well, you've separated the eye from that one vertex. But, the scary thing is that if you need

to work on the eye again, you'll probably have to separate them again. Wouldn't it be nice if

you didn't have to go through the work of selecng them again? There is a way to preserve

your selecons; it's called grouping.

Time for action grouping vertices

Grouping is prey simple; once you have selected the verces, you go to the Properes

window, create a group and assign the verces to the group.

1. Select the ObjectDatabuon on the Propereswindow header. It's the eighth

one from the le with the triangle having verces and edges, as shown in the

following image.

2. Click the LMBon the plus sign in the VertexGroupssub-panel. This creates a vertex

group, named Group.

3. Next, to where it says Name:, click the LMBover the word Groupin the buon, andwhen it turns dark gray, change the word Groupto EyeR, and press Enter.


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4. Now, click the LMBon Assign, to assign the verces you selected in the previous

Timeforaconsecon, to the Eye-Rgroup.

5. Save the le to a unique name.

What just happened?You opened up the ObjectDatapanel in the Propereswindow, and created a group to save

the informaon about which verces are in Suzanne's eye. By saving the group, you won't

have to select it again while modeling. For this alone, it's good to make grouping a roune

part of your modeling methods.

But, grouping also provides you with other benets. It organizes your object for use in the

future, when you may have forgoen completely about what happened while you were

making the object. It makes it easier for others who may also be using the object that you

make. This is very handy if you are distribung your models for other gamers or an animang

team for a 48-hour lm project compeon, or selling them on the Web.

One of the best benets of grouping comes when you are making an object for animaon. Take

a moment, and raise your eyebrows a couple of mes. Then, think about animang Suzanne's

eyebrows. A vertex can be in more than one group, and you can specify how strongly a vertex

is weighted towards a parcular group. If you had some verces near Suzanne's eye, they could

be part of an eyelid group and strongly weighted, and they could also be part of the eyebrow

group, but slightly weighted. If you raised Suzanne's eyebrow group, those verces will move

a lile, just as your eyelids move a lile when you raise your eyebrows.


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For your reference, the le 6907_04_grouping vertices.blend, which

has been included in the download pack, has Suzanne's right eye grouped.

Have a go hero selecting the other eye

As it happens, the other eye has the same problem. One of the verces for the eye is in the

same place as one of the verces for the skin. Figure out a way to select the eye, without

selecng the vertex for the skin. There are at least two ways to do it. Then, make a group

for it named Eye-L. Save your le; you are going to use it later in the chapter.

Pop quiz guring out different ways to select vertices

1. Which of these methods could you have used to solve the last Haveagoherosecon, and select all the verces of Suzanne's eye without selecng that skin

vertex? Experiment on Suzanne to test what works.

a. Use the Circle select mode with the circle made as small as possible.

b. Select the edges instead of the verces, then change to vertex

selecon mode.

c. Select the faces instead of the verces, then change to vertex

selecon mode.

Time for action scaling and rotating groups of vertices

Many mes, you want to make part of an object taller, or wider, or turned a dierent way.Blender provides some visual manipulator tools that you may enjoy using.

1. Press 1, so that you are looking at Suzanne from the front. PressAto deselect all

the verces.

2. Select most of her ears with the border select as seen here. Go close to her head,

but not into it. Make sure that the selecons are idencal on both sides.


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3. Create a group called Ears, and assign the verces to it. Save the le to a

unique name.

4. You used the 3D Manipulator for moving. Now, let's use it for scaling.

5. When in EditMode, there are three buons on the 3D View header as shown here:

an arrow, a curve, and a square with a line along the diagonal. The arrow is the

translaon manipulator. The curve is the rotaon manipulator, and the square with

the diagonal the scaling manipulator. In 3D, translaonrefers to moving something

from one place to another.

6. To the le of these three buons is one with three lines; red, blue, and green. It

controls whether the 3D Manipulator is visible or not.

7. Select the scaling manipulator buon (square with a diagonal) on the header.

8. Press Numpad6three mes to rotate the view of Suzanne about 45 degrees, so that

you can see her side. Press Numpad8to rotate the view of Suzanne 15 degrees, so

that you can see her from a higher angle.

9. Put the cursor over the green handle, press and hold the LMB, and use the mouse

to make the ears thinner. If you don't like what has happened, you can release the

scaling by pressing either the Esckey or the RMB, while holding the LMBdown.

When you like the results, release the LMBkey.

10. Use the blue handle of the 3D Manipulator to scale her ears, so that they look sort

of like bat ears, as shown in the following image on the le.

11. Use the red handle to make the ears wider.

12. Now, select the rotaon manipulator buon on the header.

13. Play with the blue, green, and red handles to rotate Suzanne's ears.

What just happened?We are being cruel to poor old Suzanne. You used the blue, green, and red handles of the 3D

Manipulator to scale her ears into grotesque shapes, and then used the 3D Manipulator to

rotate them into improbable posions.


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For your reference, the le 6907_04_scaling and

rotatinggroups.blend, which has been included in the

download pack, has Suzanne's ears extended like a bat.

Controlling the center of scaling and rotation

We're nally having fun with Blender, but it's good to be able to control your scaling

more precisely.

Time for action controlling the center of scaling

The 3DCursoris a very handy tool. You can use it to set a temporary center for moon,rotaon, scaling, and use it to dene the center of an object in whatever locaon you want.

Now, you are going to use it as a center for scaling.

1. Load the le of Suzanne that you saved aer grouping her eyes. Make sure that you

are looking at Suzanne from the FrontView.

2. Deselect all the verces.

3. Select Suzanne's ears with the Circle selecon or the Lasso tool. Refer back to the

previous secons in the chapter to refresh your memory.


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4. When you have Suzanne's ears selected, click the LMBon the second buon to the

le of the mode selector in the 3D View header, as seen in the following screenshot.

A PivotPointmenu pops up. It lists the ways you can set the center of scaling androtaon. Select 3DCursorwith the LMB.

5. First, start by making sure that the 3D Cursor is in the center of the Blender world.

6. Press Shi+Sto bring up the Snapmenu, as shown in the following screenshot.

Select CursortoCenter.

7. In our previous Timeforaconsecon, you were using the 3D Manipulators.

We don't need them now, so click on the buon to the le of the translaon

Manipulator buon, the one with the red, green, and blue lines, and lighten it,

so that you do not see a 3D Manipulator in the 3D View window.

8. Now click the LMBbetween Suzanne's eyes to put the 3D Cursor there.

9. Move your cursor a lile distance away from the 3D Cursor for beer control. Press

the Skey and move the mouse. Noce how the ears scale. Press the Esckey or the

RMB to release the ears without moving them permanently.

10.Click the LMBto the right of Suzanne's ears. Once again, move your cursor away

from the 3D cursor.


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11.Press the Skey, and move the mouse. Press the Esckey or the RMBto release the

ears without moving them permanently.

12.Click the LMBbelow Suzanne's chin. Once again, move your cursor away from

the 3D cursor.

13.Press the Skey, and move the mouse. Noce how the ears scale as in the previous

image. Press the LMBto accept the change; or press the Esckey or the RMBto

release the ears without moving them permanently.

14.Click the LMBbetween Suzanne's eyes.

15.Press the Rkey, and move the mouse. Noce how the ears rotate. Press the LMB

to accept the change; or press the Esckey or the RMBto release the ears without

moving them permanently.

16. Now click the LMBon Suzanne's nose.

17.Press the Rkey, thenX, and use the mouse to rotate Suzanne's ears. While you do

this, experiment with also pressing the Ctrlbuon, the Shibuon, and both at

the same me. You saw how they aected your moving Suzanne's eye, how do they

aect twisng Suzanne's ears?

18.Press the LMBto accept the change, or press the Esckey or the RMB to release the

ears without moving them permanently. Doesn't Suzanne look cute with puppy ears

as shown in the following image?

19.Press the Tabkey to get back into Object Mode.


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What just happened?Well, Suzanne is quite the clown. By moving the center, you can get quite a bit of control

on how things scale and rotate. You also discovered that the Ctrland Shibuons workon rotaons as well as translaon.

The point of this exercise has been to show you the power of using the 3D cursor in modeling

verces, edges, and faces, and give you a lile more experience in modeling in EditMode.

Choosing the center of scaling or rotaon properly makes modeling easier. A simple example

would be a support pier for a bridge over a valley. You could tuck your basic pier object right

under the bridge, and put the 3D cursor at the top of the pier. Go into Edit Mode, choose

the boom verces of the pier, and scale them in Zunl they hit the valley oor. You won't

have to measure the height of the pier. Another example would be if you were making the

cylinder of a gun with six chambers. You could model a secon that has only one chamber.

Then, you duplicate that secon, and rotate the copy to make an addional chamber. Then,

you repeat the duplicaon and rotaon four more mes. It's easy if you choose the proper

center of rotaon, and press the Ctrl buon while rotang it to control the rotaon of each

copy precisely.

For your reference, the le 6907_04_controllingcenterof

scaling.blend, which has been included in the download pack, has

Suzanne's ears scaled up with the center of scaling at her chin.

Have a go hero how bizarre can you make Suzanne?

Using the locaon, scaling, and rotaon controls on verces, edges, and faces, see what you

can do for Suzanne, or to Suzanne, as the case may be.

Key Funcon

Mode

Tab Toggles between the Edit Modeand the Object Mode.

Ctrl+Tab When you are in EditMode, this opens the MeshSelectModemenu,

allowing you to choose to work in vertex, edge, or face mode.

Selecon

A Select/deselect all.

B Border select, use LMBwhile selecng.

B Border deselect, use MMBwhile deselecng.

C Circle select, use LMBwhile selecng.


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Key Funcon

C Circle deselect, use MMBwhile deselecng.

Ctrl+LMB Lasso select.

Ctrl+Shi+LMB Lasso deselect.

+ Plus sign used while doing circle select increases size of circle.

- Minus sign used while doing circle select decreases size of circle.

H Hides selected verces.

Alt+H Redisplays hidden verces as selected verces.

Shi+H Hides unselected verces.

L Selects linked verces.

Transformaon controls

Shi When used with the G, R, or Skeys, it limits the transformaon to small

increments.

Shi+Ctrl When used with the Gkey, it limits the movement to increments of 0.1.

Shi+Ctrl When used with the Rkey, it limits the rotaon to steps of 1degree.

Shi+Ctrl When used with the Skey, it limits the scaling to steps of 0.01.

Ctrl When used with the Gkey, it limits the moon to steps of 1.

Ctrl When used with the Rkey, it limits the rotaon to steps of 5degrees.

Ctrl When used with the Skey, it limits the scalings to steps of 0.1.

Shi Press the Skey, then Shi+X, and you can scale on both the Y and Z axes at

the same me.

Shi Press the Skey, then Shi+Y, and you can scale on both the X and Z axes at

the same me.

Shi Press the Skey, then Shi+Z, and you can scale on both the X and Y axes at

the same me.

Shi Choosing manipulators on the 3D View Edit Mode header allows you to

display more than one manipulator in the 3D View at one me.

Shi Choosing vertex, edge, and face selecon on the 3D View Edit Mode header

allows you to select several edit modes at once, that is, faces and verces.

Shi+S Brings up the Snapmenu.

Faces

F When two verces are selected, it creates an edge, and when three or four

verces are selected, it creates a face.

E Extrudes a face from two verces or an edge, and it can be used on mulple

edges as well.


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Summary

That was good. You learned a lot about the basic skills needed for creang and working with

verces, edges, and faces. You were introduced to Blenders mascot - Suzanne. You got a bit

of experience in troubleshoong a model, seeing the how much dierence changing center

of rotaon and scaling can make in the model and you learned how to group verces, edges,

and faces. Congratulaons!

Documents

Blender - Making Precise Selections