USEFUL BLENDER 3D TIDBITS (PERHAPS) You may not know about much and were afraid to ask *
Anything completely wrong let me know. These are notes to myself mostly ... which somebody somewhere perhaps could benefit from, though perhaps not. This page has got too big and I will have to have an index page soon.
Topics so far:
L Key -- Shadowy faces -- Aligning along axis -- Crazyspace -- Cockeyed Mirroring ---Spin Quads --Toggle Visible -- Extruding along the normal --Shutting off Lamps without deleting them -- Renaming objects in the Outliner window-- Hide part of Mesh during Sculpt and more!
The L key allows you to select groupings of vertices inherent in a model made from other programs, it's a way to get at them. And this can be very useful, especially if there is overlapping groups. It can be a lifesaver. If you know Elements in 3ds Max, that'll give you a good idea what I mean, as the L key will recognize the elements in a model made in 3ds Max. The L key will also recognize the different parts of a OBJ file exported from other programs.
You can create yer own Elements in Blender. Please note this is different from vertex groups made in the usual way in Blender by using the Vertex Group panel (New/Assign, etc). In fact the L key will not recognize those groupings ... To avoid confusion I'll call these 'other' connected vertices 'Elements' like they do in 3ds Max.
We can create an example in Blender actually, yes, we can create our own Elements, either of two ways, to enhance our understanding of how it works.
1) Start new. First add a cube. Move it over a bit so when we add a plane, the plane will not lie right over the cube. While in EDIT mode, add the plane. As you probably know, if you add another object while in EDIT mode, that object will be part of the same mesh as whatever you are editing.
However, the new plane is a different element than the cube, and we can confirm this by using the L key. First de-select all the vertices. Next, hold the mouse over the cube and hit L. You should see the cube selected but not the plane. If nothing is selected, try to hold the mouse of a cube vertex and do it again.
Deselect and then hold the mouse over the plane. Hit L. Should see the plane now selected but not mesh. Note that there are no vertex groups in the editing panel, this is different.
2) Another way to create them. Start new. Add a cube. Move it over. Now add a plane again, but this time while in OBJECT mode. So you should have two objects. Select both objects and join them into one mesh by Ctrl-J.
Go into EDIT mode and deselect both. Now hold the mouse over the cube and hit L! Only the cube is selected.
The L key always adds one element to the other, so if you want only one, you have to deselect everything first.
Sometimes when you are editing, especially if you have been busying cutting, then extruding for a bit, you may begin to see mysterious shading on faces in the regular 3d display that you can't account for. Sometimes you won't be aware of it until you apply subsurf, and then shadows appear. You didn't see it before because you don't work with single-sided faces (double- sided button off), probably. If you did, you would see some faces as black because they are facing the other way.
Re-calculating normals often will set things right (other way: the more tedious flipping of normals of the offending faces by hand). ... Must be in edit mode to do this. Select ALL vertices. Hit Ctrl-N.
Another use for Ctrl_N: If yer adding bones to an armature and moving them around, and they start looking twisted, Crtl-N will help straighten them out, get them all even-looking without moving their location.
Ok, suppose you have a bunch of vertices which form a curve, or a jagged line, or something like that, just something that is not straight line and you want them to form a straight line. You want them to line up along the X, Y or Z. One way to do this is to scale them to 0. If for example I am in the XY view (Z goes into the screen), and I load a sphere, then select the top quarter of it (a dome shape), and hit S\Y\0, the vertices will line up straight along the X. This can be very useful and I didn't know about it for a long time ... not sure why.. There's also scaling to -1 which mirrors an object, but this I knew about from practically day one.
V key. You may find you want to separate some vertices, to open up a rip. For an embarrassing long time I didn't know how to do this. Something I may have skipped when racing thru beginner pages, I dunno.
Ctrl-Shift-S ... to round a cross-section of something, like a leg.
Known as 'spin quads' in other software (I remember it as 'turn' in 3ds Max). Select two faces, hit Ctrl-E, and pick 'rotate edge' from the Edges menu. One use is for folds in clothing cutting across...
USE EMPTY TO PLACE A LOGO
Create empty object, place it where you want the logo to go on base object. Set texture on base object MAP INPUT to 'object,' and put name of empty in box.
SEPARATE BONES INTO A NEW ARMATURE
Ctrl-Alt-P (Recent addition by Blender)
Shoulder is a common example. Suppose you move yer armature in pose mode so arm is vertical up, and it doesn't look right at the shoulder, and you use shapekeys to correct it. And you edit a shapekey while you have both subsurf and armature enabled in edit mode, so you can see what the end result of shapekey on the shoulder. It used to be the vertices when you moved them would move in weird ways, a.k.a. 'crazyspace' but efforts have been made by Blender to correct this. It seems to still happen though unless I have armature modifier above the subsurf modifier.
Sometimes it appears not to work. Why? Because the center of the original object has gotta be put to where the center of the two mirrored together will be ... That means place the 3d cursor over to the mirror line and then SPACE and 'center cursor.'
Everybody knows about H and Alt-H for hiding and un-hiding. But Alt-H unhides everything ... suppose you want to un-hide just one of the things that were hidden?? You can do this by toggling invisibility of any object in the Outliner window. This window I have open when I model for things like this, or just to keep my bearings... Anyway, just right click the object in the Outliner window and select toggle Visible or click the little eye icon. There's also toggle Selectable and Renderable, as well as you can delete objects there.
The Renderable setting in the Outliner window is handy for shutting of lamps. If you have a bunch of lamps on but you don't want them all on and you don't want to delete them cuz you want them for later, just turn off the Renderable setting for the lamp(s) you want off.
This is something you don't think about until you face a problem that you have to do it. (Like belts: you can have a belt hug the body easily. Lay a belt plane on the body using Retopo, and then extrude to give it thickness). Suppose you want to extrude from a surface, normal to the surface all the way along. And suppose the surface is curved significantly so that scaling outward doesn't look right! The key combination to perform extrusion along the normals is rather obscure-looking: E/ESC key/ALT-S
The ESC key removes the along axis option and the ALT-S brings in the 'Shrink-Fatten' mode. Example below:
* Recently I spotted a script bundled with blender called 'Extrude Along Normal.' It's under MISC in the script menu. Had no luck with it.
Ctrl-Shift-Left click will draw out a box to isolate what you want to sculpt, yes, while in sculpt mode.