Blender 3D: Noob to Pro/Cool Things

Cool things in Blender that aren't that obvious. Useful tips and tricks in Blender.

Attribution
Many of The Following Tips and Tricks have been contributed by members of the CGsociety.org, a Public Society for Digital Artists. The tips have been extracted from a CGsociety thread. They have been roughly edited to improve readability.

Delete, Move, Rename, and Make Directory
When you are inside a file browser for loading or saving something and you want to create a new directory, just add the name to the path on top of the window and confirm 'Makedir'.

you can also delete(x), move(m), or rename(n) a file. you can do action on multiple files by seling with right click

Preview images when loading them as a texture
Whenever you are loading images as a texture, you can hold down Ctrl while clicking on the 'load'

Trick for Creating Quick File Revisions
After you have saved a blend file or an image you can then save it in progression that is:

car .blend. or car .JPG

Next time do "Save As" then press the + (plus) key which will advance the blend file by 1 every time it's pressed. example: car .blend becomes car 1.blend. press again car 2.blend and so on.

The - (minus) key will subtract one. I've gotten into the habit of saving frequently. Yeah I know there is now the undo feature but I like this better because it gives you a history in case you need to back a few levels of a build. You get a saved version at the level you choose.

Note: Blender automatically detects the number... meaning it does not need to be in any position. For instance: If you have a file named 001starport.png or .blend or whatever, pressing the + (plus) key will automatically name it 002starport.png. If you want to name it starport1.png, it will change it to starport2.png.

Two rules: The filename has to have a number. It can be 0, or 1, or 3.141569.

If the file number is a negative, pressing + (plus) key will increase the "magnitude" of the negative number. I may have used magnitude wrong, if so, I mean pressing the + (plus) key will make -0.04 drop to -0.05. The - (minus) key will bring you only to 0, and then it will start to eat itself up.

Open Recent
Control O

Constrain Movement to one Axis or to a plane
when moving objects/vertices or set of objects/vertices ([G] key) if you move in the direction of the global X axis (Up/Down) and then press the MMB, movement will be constrained to only move in the X axis, or if you move the vertices in the direction of the Y axis and then press MMB it will be constrained to move only in the Y axis. The same is true of the Z axis.

You can achieve the same effect by using the X, Y or Z keys while in grab mode. You simply have to press X key, Y or Z, once to lock to X Y or Z global axis,*

To Constrain the Movement to two axes (a plane): Press Ctrl+X to move in the Z-Y-Plane. Ctrl+Z=XY, Ctrl+Y=XZ.*

Alternatively, Select scaling mode and select the axis not to scale with the selecting button at the same time as you hit Shift.


 * in every case You can hit the X,Y or Z button again to constrain movement to a different set of axes. Normally this different set of axes is local. However you can change the identity of this set to global, local, normal, or view by pressing Alt+Space. which cycles through the different identites.

Note: All of these shortcuts work with scaling and Rotating as well

Shrink/fatten mesh in direction of vertex normals
When you're mesh-editing, Alt+S will shrink/fatten the mesh selection in the direction of the vertex normals.

Vertex Parenting
You can parent object to a Mesh, in that case you are parenting to the center of the mesh.. BUT if the mesh is translated somehow (let's say by an armature'[S] pose) the center remains in the same spot, and thus the child object doesn't receive any transformation at all.

To solve this, you can parent the child object to a vertex (or a face) within the mesh, and any transformation that the vertex receives is passed to the child.

There are only 2 options, to parent to any 3 vertex within the mesh or to parent to just one vertex. If you parent to 1 vertex then only location information is passed, with 3 vertex all transformations (rotation, location and size) are passed to the child.

How to do it? Starting in object mode select the child(ren), hold Shift and select the parent, enter edit mode, select one or three vertex, press Ctrl+P. That's it!

Work around to welding Verts
For Edge loop (Verts) position both loops together as close as possible then hit W then 4 (not on numkey pad). You can adjust how far the effect of collapse can go in the Edit window (a button on the right labeled Limit: ***, where * is a number).

As for individual Verts, e.g. Two vertices welded to become one, select both Verts, scale until they are very close then hit W then 4.

you can also do this with the snap combo

select the vertex you want to weld together Ctrl+S, Cur -> Sel Ctrl+S, Sel -> Cur [W], Remove Doubles

Also, whenever Blender pop up a menu with different options, you can just type in a number to choose one of the options (use the numbers not on the NumPad)

Make individual objects the camera and Change them back
If you select certain objects and press Ctrl+0(zero)it will make them the camera. I use it all the time to align spotlights.

Select your camera and hit Ctrl NumPad 0 to make it the active camera again

Ordering Meshes in Vertex Groups
If you are preparing to skin your meshes and you are ready to create the vertex groups, you should pay attention to the order in which you create them, because once they are created there is no way to re-arrange them on the vertex-group list.

That means that if you are a ultra-by-the-book person and you would like the vertex group alphabetically ordered on the list them you must create them in alphabetical order.

.. Or, if you would like them to be ordered according to their function (shoulders, then arms, then forearms, then palms, etc. you must create them in that order.

This may all sound like a stupid thing to care about, but If you have a character with 39 vertex groups you may quickly find that when one of them needs fixing it is a little difficult since they were randomly created.

Position and scale along face normal,
-Shift V: Position camera along face normal, Alt S: scale selected vertices along face normal

Using Fake Users
pressing Shift+F4 will turn the window into a ¨Data Select Window¨ where you can assign and unassign fake users to almost everything by selecting the name and pressing the F key

Creating a fake user allows you to keep useful data blocks (materials, textures, base meshes) at hand even if they are not linked to an object. You can use it to set a default material that would have the shader you like best.

Align a selection of vertices on a plane
If you want to perfectly align a selection of vertices on a plane, you just have to follow these little steps:

1.) Before you are selecting the vertices you want to align, position your 3D cursor in the plane that you want to align to (you could select the 4 vertices of a big plane and hit Shift+S / Cursor->Selection for example, but you can position it anywhere)

2.) Now select those vertices you want to align

3.) Choose "3D Cursor" under "Rotation/Scaling Pivot"

4.) Now with the [S]-key start scaling mode, hit the key of the axis you want to move the vertices on (X,Y,Z)

5.) Holding down the Ctrl-Key, you can now move the vertices in one line towards the cursor, until the value for the chosen axis is 0.000. Alternatively, just enter, using the keyboard, the scale factor you want (0 in this case).

6.) Hit LMB. The vertices are perfectly aligned along a plane through the 3D cursor.

This even works very well while in perspective view mode, so you can align on the fly and don't have to switch to front/side/top view all the time.

Welding Vertices
You can weld vertices by selecting them in edit mode and pressing Alt+M.

View wireframe of hidden Verts
to view the wireframe of hidden Verts, make sure you are in WIREFRAME MODE and then turn SubSurf on and change the level to 0 If you already knew about this then

Select a true loop
shortcut is Shift + Alt + right Button of the mouse, serves to select true loop, in vertices as in edges like in faces.

Selecting one object from a single mesh comprised of multiple objects
If you have more than in Edit Mode, you can place your mouse cursor next to one of the Verts in the desired object, then press the "L" key to select all of the Verts linked to that one. "Alt+L" reselects in the same manner.

Precise Zoom and Select/Deselect
Selecting: If you Hold down the Ctrl+LMB (left mouse button) and drag the mouse, it will allow you draw a selection as opposed to using the B button which gives you a square.

Deselecting:To draw an area to deselect, Hold down the Ctrl+ Shift+ LMB(left mouse button) and drag the mouse,

Zooming:Hold down the Ctrl+MMB. Move your mouse vertically to can get a more controlled zoom versus scrolling the Mouse wheel.

This feature may not be present in 2.37 or earlier versions.

Mouse Gestures
Left click and draw:


 * a straight line - moves the selected object.
 * a circle - rotates the selected object (note: this must be drawn fairly circle-like).
 * a V - scales the selected object.

Selecting Obscured or Hidden Objects
Say you are in front or side view and you want to select an object, but it is obscured or hidden behind other objects. If you press Alt RMB over a group of objects, a menu will be displayed in the 3D window allowing you to pick the object you wish to select.

Select or Deselect Multiple Vertices
In Edit mode, when you click the RMB near a vertex that vertex (face or edge)will be selected, RMB again will reselect. By holding the Shift key this will allow you to add each selected vertex (face or edge) in that highlighted group.

Pressing the U key (Undo in Edit mode) will also remove the last selection you made.

Alternatively, you can Press B and then draw a box with MMB. Anything caught in the box will be deselected. Also works with BB and the draw selection. Draw with MMB and you reselect.

Selecting multiple items
You can hold Shift and use right mouse button to select multiple items to append.

Measuring, length, distance on an object.
Hit "F9" (editing), you should have split (2) windows. One "3d" the other "buttons" go to the Mesh Tools 1 panel and press the Edge Length, Edge Angles and the dimensions will appear on your selections in the 3d view.

Adding Connected Vertices
In Edit Mode, if only one vertex is selected, pressing "E" will add a vertex, on a freely defined place, connected to the selected one. As will holding CTRL and left clicking the mouse where you want the new vertex to be positioned.

Note: It must be an Image texture and in wireframe mode to be visible.

(2.37a)

Recalculate Normals
Ctrl + N = Recalculate normals outside (you might have to select faces before doing so) Shift + Ctrl + N = Recalculate normals inside

These two hotkeys are useful when you extrude some edges and see a kind of seam in between (due to normals pointing in different directions).

Then, after selecting an edge, Ctrl + NumPad(+) selects the face associated with this edge. Ctrl + NumPad(-) deselect the face.

Create a Quad from two Tris
Alt + J when having two Tris selected makes a Quad.

Remove Doubles
To Remove Doubles use hotKey: W. You can adjust the "limit" option so that "Remove Doubles" has more or less tolerance. This option is located in editing window under the mesh tools panel, (i.e. weld vertices that are further?)

Combine edit levels on a mesh.
When in Edit mode for a mesh (TAB key) you can choose the level that you wish to edit at. At the bottom of the 3D window, there are four buttons. Vertex, edge, face & back-face cull.

By default the vertex level is selected, if you hold Shift and press the edge button, you can use both at once.

Change Select Mode
to change select mode (vertex, edge or face) you can press Ctrl+Tab. But this way you can't use the Ctrl+Key to ADD the select modes.. Still could be useful, if you don't have a header for the window you're working in..

Precision Warping
When using the warp tool (Shift+W) you may find that there are times when you have trouble perfectly closing a 360-degree loop. This is because Blender will warp based on the total width of the selection, which may not necessarily be what you want.

Getting around this is simple, just select two verts to denote the new endpoints, duplicate them (Shift+D), scale the two verts times two, so they are just twice as far apart. Then select what you want to warp plus those two marker verts, and warp 720 degrees.

When done, click a vert on your mesh and type L to select everything linked to it. Then type H to hide it. Once you've hidden all of your mesh, all that remains are the two marker verts. Do a Select All (A) and type X to delete them. Now unhide your mesh using Alt+H and you have just the warped mesh, extra guide verts are all cleaned up.

Precision Cutting
The Knife Tool can actually be quite precise if you take advantage of the snap feature. Press K, choose "Knife(Exact)" and then hold the Ctrl key while choosing where you wish to cut and you will find that the path to be cut will now snap to nearby vertices.

Keep in mind that the vertices being snapped to don't have to be the ones you are cutting. Say you want to cut the midsection out of a UV sphere and you want the cut to be two grid units in height. While viewing the side of the sphere, add a plane, and scale it to be two grid units tall, and wide enough so that it extends beyond the sphere. Now select the vertices of the sphere (because what we have selected is what gets cut) and when you cut it, snap to the four verts of the plane. Now hit Enter to apply your perfect cut.

Using guide geometry such as a plane to cut other geometry "cookie-cutter" style can be extremely useful when accuracy is needed. Remember to align your view before cutting, since your view will determine the angle from which the geometry is cut.

Turning Sub-Surfed Mesh into Normal Mesh
If you have a sub-surfed mesh you can turn THAT sub-surf mesh into a normal mesh. Just select the sub-surfed mesh and press Alt+C (Conversion).

How to remove (numb) black spots on a Mesh
If a Sub-Surfed mesh becomes (numb) black on some places, that's because of the normals. Select all and press Ctrl+n and then confirm. now it should look prettier!

if the above solution does not work, save your Blend file, Quit Blender then restart. Use Ctrl O to open the last file and your mesh will have returned to correct shaded state.

Select all holes in a mesh and fill them
Shift+M* selects all Non-manifold edges/vertices (holes) in a mesh **. Then all you have to do is hit Ctrl+F to auto-fill those holes with "beauty fill".

Shift+M is an alternative shortcut for 'Select Non-manifold'. You'll find this in the select menu when in mesh edit mode. The listed short cut there is Ctrl+Alt+Shift+M. Shift M is obviously a lot more comfortable on the fingers though! Although 'Non-manifold' usually refers to holes in your mesh, it is not necessarily only holes e.g., an edge with three faces coming out of it is also a non-manifold edge!

Fill in four or fewer vertices
Select the vertices and press [F], this will fill in the empty space around them.

To clean up a filled in space, select all the vertices for the area, and press [F]. Choose OK to make FCon. For example: add a plane in wireframe mode, extrude it several times, select all vertexes, then hit [F].

Animation Preview in all windows at the same time
It is well known that Alt+ a is for previewing an animation on the 3D window. But that's not all of it. Divide your screen into multiple 3D Windows, each from a different point of view.

Press Alt + Shift + a

Enjoy!!!

If you have an Action/Ipo Window and 3D windows open, and you issue the Alt + Shift + a command from the Action (or the Ipo) window, it will animate both (the action and the 3D) in sync!! Great for visualization of Ipo's effect on your model.

Choose animation mode, Convert mouse movements to IPO
-T in IPO window: Choose animation mode, i.e., linear, bezier, constant -[R] in IPO window: Record mouse movements, and convert to IPO

Animate procedural textures
To animate procedural textures, press 'i' with the mouse pointer in the materials window, and select the type of Key-Frame you wish to set in the pop up menu. advance a few frames, tweak your materials, and set another key frame.

Blender color picker
Blender has a PhotoShop-esque color picker. Simply click on the color preview next to the sliders to use it. Hit enter when you have the color you want.

Saving your face groups selections
Regarding UV mapping and Face Groups Selections there seems to be the general misconception that you can't save your face groups selections on Blender.

Most people already know that from within the Face Select Mode (Potato Mode) you can switch into Edit Mode and whatever selection you do while in Edit Mode is passed back to Face Select Mode when you exit the Edit Mode.

Well, Did you ever wonder why Material Index Groups (that are nothing more than face groups with a common material on them) have those little 'Select' and ´Deselect' buttons there? Sure they come handy for later modification of the material index but that is not all about them.

Do this: Before starting the UV unwrapping job, cut your mesh by creating as many material indexes as you need, you can even assign each one a different color so you can be sure that there is no face orphan. Once you have the mesh all cut and sliced (so to speak) you enter in Face Select Mode, then switch into Edit Mode, select the index containing the faces you want to unwrap, press 'Select', leave Edit Mode and Voile! You now have an entirely useful face group waiting for you to unwrap. No more manual (and imprecise) face selection is needed.

If you later need to change the mapping of those faces, don't fear. Just make sure there isn't any face selected on Potato Mode, do as you did first (enter edit mode, select the index, exit edit mode) and there are your very same faces selected again with the UV mapping you already assigned to them.

Note: Another benefit of have precise face selection groups is that, initially, you don't have to worry about UV coordinates overlapping, since you know have the way to select ONLY the faces you want to. For example, you unwrap all your faces by groups and when you are done you can start thinking about scale and position within the texture map, not like before when you have to solve those things as you go.

Bulk Texture Change
Consider a scenario in which you have a scene with a 100 mesh objects, and 50 of them have one texture and 50 of them have another.

If you want to change the texture of the first 50, but don't want to change each individually, do the following. Add a Plane out of the view of the camera. Add your new texture (Material) to the plane. Then use the “Copy to material Buffer” button in the header of the Material buttons. Select one mesh object of the same sort that you want to change, open Material buttons and Paste from Material Buffer.

All the mesh objects with the same texture will now have the new texture.

Alternatively, If you have a material that you want to apply to a lot of objects at once:

1. Select all the objects you want to apply the material to. 2. Apply a material. (this only applies to the last selected object) 3. press Ctrl+L > Materials. (this links the material of the last selected object to all the other objects)

Negative Meta-Balls
Add>Metaball as usual. Exit EDIT mode and Add>Metaball. This time before you exit EDIT mode, hit the Negative button in the EDIT buttons window. Then leave edit mode.

If you move the negative Metaball around, you can see the effect it has on the positive metaball.

Be careful though, as negative metaballs are not displayed in the same manner as positive metaballs, you will only see the Pivot point not a meta-mesh.

This is a little test you can try to see the amazing effects negative metaballs can produce.

Make 1 Metaball, make it big. Place three spheres (UV) inside, make them emit particles, one 100, one 200, one 300 particles. Parent three negative metaballs, one to each sphere, and use dupli-vert on each sphere. Make the 100 duplicate metaball quite big, the 200 medium and the 300 small. Hit Alt A to run animation in 3D window.

( Click here for this author's negative-metaball thread ... oops, it's not there anymore, well, not the AVI anyway!)

(Click here for this author's negative-metaball AVI.)

Maintain the UV layout when moving/scaling/rotating UV co-ords.
When you have the UV image/editor window open and have loaded an image you want to UV map to a mesh, click on the UV tab in the header bar and turn off 'Snap UV to pixels'.

This will help to maintain the UV layout when moving/scaling/rotating UV co-ords.

Tricks, related to the view ports and the render buffers
First. Switching among screens

So you have your screen made off the 3D window, the buttons window and the info window... but you are doing some fine tunning to the mesh in two places simultaneously, and they both need to zoom in the 3D window. You could scroll or zoom out, translate the view and zoom in again. None of them an elegant solution.

Another situation. You are working on a model and are using an image for reference. You are not tracing over the photo, just take a look at it often to make sure you don't deviate to much from the concept. So you open the photo in a 2D program and keep switching back and forth from Blender.. or you have the photo open in an image window and keep maximizing and minimizing the window... another hassle

Worry no more!!! Blender can handle multiple virtual screen (ala Linux) and you can come and go from them with just one key stroke.

Just press Ctrl+Left Arrow or Ctrl+Right Arrow (for all of you OS X users, add a Shift) and you are switching screens. Go ahead! By default EVERY .blend file comes with 3 screens ... and of course you can add/delete as many as you see fit.

the magic button to add or delete screens is right beside the Tools menu, up there in the info window.

Using the render buffers
Ok, so you set your scene and press RENDER, a nice window comes up and you see your hard work coming to existence (that's the default behavior, if your change it on the display buttons then this may not work for you).

Do you realize that the window containing your render image is also a render buffer? Actually they are 2 buffers for your to play with. Whenever the render window is open (and you can re-open it by pressing F11 without having to wait again for the render) if you press the J key you can switch from Buffer A and B. (the last active one is what you save when you press F3). You can even switch buffers in the middle of a rendering (but I advice against that when rendering very complex scenes, you have been warned!)

The cool thing about having two separate render buffers is that you can have instant before-and-after images for things that you change in the scene. For example you are searching the perfect position for a light source in a scene, you place it and do a render, place the light in another position, switch to the second buffer and do a new render. Now, with the render window open, just press J to see how the change on the light's position influence your scene and that makes your decision easier.

By the way, the render window can be zoomed (by the normal ways or by pressing Z ) to do a closer inspection of the image.

Render window Tricks
To zoom into the render window, use the ZKEY.

To find out what the (Red, Green, Blue, Alpha) values of rendered image are, left click and hold the button of your mouse.this will reveal the RGBA values of the pixel below the mouse cursor. i.e. R 127, G 255, B 13, A40. The values will appear in the bottom left corner of the render window. You can also hold the button and drag the mouse around. This will display the values of the pixels your mouse pointer passes over.

With the render window open, you can press AKEY to view an alpha version of the image. Press AKEY again to go back to the normal colour view.

To do a before/after comparison after making a change, hit JKEY to switch render buffers, then hit F12 to render. In the render window, use JKEY to alternate between the previous render and the current one, so you can easily see the differences.

Working while you Render
If you use a X/X11 based window manager, you do not need to watch blender while it renders, go to a different virtual desktop. Blender doesn't have to keep X informed of what's going on and rendering speed may increase.

Border Rendering
In the rendering buttons find the buttons marked "Border" and "Crop". If you depress "Border", you can get a rendering of any part of what the camera sees. Just do the following :

Go into a camera view using NumPad 0, press Shift+B. Then, mark the limits of the rendering as you want them using LMB. Next, render the usual way and the section you marked will be rendered first, then it will be integrated to the complete rendering. If you wish that *only* the chosen section would be rendered then click on the button marked "Crop" also.

Creating a cluster of particles which takes little time to render
Render some particles, and make the picture into an alpha mapped tga in GIMP or whatever graphics editing application you use.

Load the image onto a plane. Adjust the alpha settings accordingly. Parent the plane to the emitter. Press dupli-verts.

You now have a cluster of particles which takes relatively little time to render. Of course it doesn't have to be an alpha map of particles. That's entirely up to you.

Alpha from render view
When cut & pasting stuff from render window to {insert your favorite image editor here} using Alt+ PrtScr, cut and paste the render first, come back to render window and press "A". It changes the view to alpha and you get black & white mask to cut the background nicely in the {again, favorite image editor}. Nice when you do testing in low res.

View alpha texture as wire.
Ctrl+d in 3d very usefully for preview without rendering.

Also, if you have an object (works best on a mesh plane) with an image texture, you can use Alt+V key outside edit mode. This will adjust the object's size values so that the image won't be stretched when projected.

Restoring your “lost” work.
If you go to the temp folder where you have Blender save its temp .Blend files, reload the most recent one and this will save you losing the whole of your work. You don't even need to save a .Blend file for this to work. You can change the settings for this in the tool window at the top of the Blender screen.

Built in Hot-Key List
Since the few last versions (since 2.28 I think) blender has a built-in all inclusive hot-key list. Just open a text-editor window, and right besides the option to create a new text-buffer there is a menu option called ¨KEYLIST.intrr¨. Select that option and the full list is loaded in memory

--Edit: There may be many hot-keys missing, especially the newest ones, like M to mirror a mesh, K for the Knife tool, Alt+Z for textured view... but the list is a good start at least.

Un-compiled PlugIns
Blender can load plug-ins for texturing, sequence editor, etc. . However, Blender comes with a few of such PlugIns un-compiled.

In Linux they are located on the plug-ins sub-directory of the default Blender install, and all that you need is a Make command to compile them. I don't know how to compile them in Windows, but there they are, just waiting for you to awake them!!!

Blender “Easter Eggs” (Weird things included in blender)
All Publisher versions of Blender have been shipping with a Monkey mesh called Suzanne. Just open the main tool box (Space Bar) -> Add -> Mesh -> and right below the other primitives you'll see the Monkey.

Why/What it is for? Only NaN programmers know*. It is supposed to be a private joke among the blender developing team. Since then, its considered as a sort of mascot for blender. However, it is incredibly useful as a quick complex object for testing textures, shaders, etc..

By the Way, Suzanne isn't the only joke included... but I won't spoil the surprise. You will bump with them on your daily work, that is for sure.


 * NaN was the company that originally developed Blender

Try this: run blender with the -Y argument (open the command prompt/terminal, go to your blender executable file folder, and type blender -Y)

Weird Error Message
Sometimes, when trying to use a boolean on a tri-based mesh, Blender gives the prompt: "Wanna Crash?" >Yes Please!

but clicking it doesn't crash. This is because Blender is a lot more stable now compared to when that 'crash' request was coded. It also used to appear when using beauty fill after face fill. (Ctrl+F in edit mode)

Blender 2.37 now has a 'widget', which replicates the red/blue/green axis symbol in 3DSMax in the 3d windows. Rotation scaling and movement of objects/Verts/faces etc., can be manipulated using the widget, or in the usual manner of earlier versions of Blender.

Turn your blender animation into a screen-saver (Windows)
to turn your blender animation Windows binary file into a Windows screen saver, rename the EXE file into SCR and right click it and install !

Discover the FPS rate of a Window
If you hit Ctrl+Alt+T key in a window, Blender will tell you how much time it takes to render a single frame of that window, in milliseconds. Valuable Benchmark

???
using construction widget press Shift to get precision mode for fine tuning. Release left mouse button (LMB) and holding Shift down press it again, then you'll get moving along another axis.

Sculpt Mode Hotkeys

 * F: an interactive brush resize
 * Shift F: an interactive brush strength adjuster
 * Ctrl F: in interactive texture angle adjuster for your brush.
 * Shift B: a rectangular zoom selection for close-up work
 * Alt B: hides all but selected rectangle
 * A: toggles airbrush
 * S: smooth
 * D: draw
 * G: grab
 * L: layer
 * I: inflate
 * P: pinch
 * V: toggles add and subtract in draw mode
 * Use X, Y and Z to toggle axis mirroring.