Guide:Blender

Hello and welcome to Bellimora's little guide of mesh creation for SL and possibly even MCM. I created this guide because a few people I know are showing interest in blender, so I'm going to infodump all my secrets and tricks and money here, with PICTURES! So, dig in and have fun!

Mesh Basics

Now before we go digging into making a mesh for SL I'd like to go over the limitations and abilities of mesh here and compare it to sculps. Let's take a look!

A mesh has the following limitations:

• A mesh may have up to 8 textureable faces divided and arranged however the mesh creator sees fit.
• Unlike a sculp a mesh may have as little or as many polygons as the author pleases.
• Mesh vertex placement has floating point precision, that is it's coordinates can have decimal values.
• Mesh has a prim equivilence rating, how many prims it takes up.
• Prim equivilence is the higher of the following two measurements of a mesh: Physics, and download weight.
• Having a lot of polygons gives a mesh a heavy download weight.
• Forcing a mesh to very accurately emulate an intricate shape for people standing on it and objects colliding with it will make it have a heavy physics rating.
• If physics and downloa are below .5 then the mesh will be .5
• If two .5 meshes are linked together into a single object in SL, the objects prim count will be 1.
• If you want your mesh to have a minimized prim count, keep the physics emulation as simple as you can get away with, keep the amount of polygons used as low as possible
• Unlike Sculps you can manually set each level of detail LOD of the mesh. This allows you to set how the mesh simplifies itself as the camera zooms away from it.
• If you manually set the LODS and give them a lot of polygons it will REALLY increase the prim count of the mesh AND it will be a resource strain on any viewr looking at it.
• Unlike sculps you can manually set the physics for your mesh by uploading a model i the same general shape you want to use for physics detection.
• Be aware that SL will stretch whatever you upload to fit the dimensions of the mesh, this might make weird shit happen.
• People with older viewers will see mesh as various prim shapes instead. Such people are a minority currently.

Sculps:

• Sculps are always one prim.
• Sculps use integer for vertex placement perfectly flat smooth surfaces and curves get tricky, some lumpiness is inherent
• Sculps have a single texture face
• Multiple sculp maps can be cycled on a single sculp to animate one far more easily then you could with mesh.
• Sculps are compatible with lower version viewers.
• Physics on a sculp is a sphere, at times it can be a bit derpy. Best you can manage is stuffing a prim inside a sculp to match the physics you want.
• Level of Details on a sculp are automatically calculated by SL, at range intricate objects tend to collapse in unpleasent ways.

In short, when using mesh if you want your prim count low, keep your polycount low and keep the physics simplified (in fact I make a box-shaped mesh and upload that for the physics on stuff I don't care how hit-detection is factored if the physics comes up high naturally).

Blender Basics

Here it is, the blender view screen

Window Layout

Now before you make and upload mesh, you need to figure out how to use the program. To the right side of this section, there's a picture of blender's main view screen. I've highlighted some areas with color. If you click the image you can get a larger view.

In red in the upper left hand corner is the menu bar. The little minus sign in a circle if pressed will make it vanish. press it again to make it appear again. I once made that vanish accidentally and worried myself some. Figured I'd mention it now in case you accidentally do it too.

In Blue to your left is the tool box. Press T to toggle that on and off.

Below that in purple is a button that if you press that it'll open up a list of work-space types. You'll need to use that when texture-mapping. It has a pile of different workspaces i don't even know what they do. If you're a power use you might want to play with some of those later.

To the bottom of the window highlighted in black is the mode selector. The three biggie modes you want to be aware of are sculpt mode, edit mode, and object mode. Object mode lets you select move and resize individual meshes in your blender work project. Yes, you can make multiple meshes at once and upload them all as a single linked object that you can dissect later. Edit mode lets you get in there and hand-edit vertecies, delete them, split them, all that nitty gritty precision stuff. Sculpt Mode Lets you make broad changes with a variety of sculpting tools. Sculpting does not add vertecies or any other points that can bend, so you better pre-prepare a surface to be rather flexible before trying to use it. It's great for organic curves.

Now selected in white to the right of that is a selector that lets you set if you are dragging, rotating, or scaling stuff. In your blender view it probably has more buttons then it does with me. You know when you go into edit in SL and you can click that button in the edit window to select if you're moving or rotating or whatever? If you're anything like me you likely prefer to use use the hotkeys to do that stuff and don't click. If you are like that, go ahead and click that weird 3 bar colorful icon that looks like the only button I have. That'll be handy for doing all those types of edits via hotkey, makes those annoying arrows vanish. Purely a thing of preference however.

In Yellow to the right is a toolbar of various buttons, click it and it'll fill the panel below with all sorts of options. If you middle-mouse-click-and-drag you can move that bar to the left and right at get are more options. I'll be pointing you at stuff up there later.

Now that little seafoam green box in the upper right? If you click and drag that you can make additional windows, and set them to different workspaces. THis will become VERY handy when setting up your textures in UV mode since this will let you multitask. To get rid of a window. Click the corner you dragged out to create it and drag it in the direction of the window you wish undone.

It's not visible in this screenshot, but if you hit tab and go into edit mode. Three buttons will appear RIGHT next to the highlighted in white thing to the right of it. They are only visible in edit mode and they select if you can highlight vertices, edges, or faces.

Hotkeys

I'll hit you now with a few basic hotkeys that are indespensible.

CTRL+Z - This is undo. This is your bestest friend in the world. This lets you experiment. Everytime you do something you don't like CTRL+Z. Selecting something or unselecting it incidentally is considered an action that you can undo. Great for intricately selecting a bunch of vertecies and then messing it up at the last moment, you can go back.

Left Click - This will make your 3d cursor move. All i know about the 3d cursor really is if you make something new, it will appear initially at your 3d cursor. Shift+S will give you a menu option to recenter that bugger.

Tab - Toggles between object and edit mode.... unless you used the button I mentioned earlier in the UI to go into sculpt mode. In which case it'll toggle between sculpt and object mode until you go and manually select edit mode. Thems the breaks.

X - This will delete stuff. You'll likely get a menu of delete options if you are in edit mode. The Dissolve entry is particularly handy. It makes the highlighted thingy vanish by merging the stuff on either side of it together. Great for making lines vanish without making faces vanish.

Right Click - Highlights stuff. Blender's weird you'll be right clicking far more then left clicking.

Shift+Right Click - Let's you highlight more then one thing.

Alt+Right Click - Highlights multiple lines/vertices in a row. Real handy for selecting a pile of things fast.

B - B is for BOX, it lets you lasso select everything in the box. Lasso select only selects things the camera can see. So if you are in edit mode, and you do it to a box, you'll only select half the box. If you want to select the entire box at once, hit Z to go into wireframe mode and THEN lasso select.

Middle Mouse - Changes camera angle. Holding shift while clicking middle mouse will move the whole view.

Keypad 5 - Orthographic view toggle. Default view is linear perspective type stuff. stuff far away looks smaller. Great for seeing how it'll look when rendered in world, horrible for precision aligning stuff. Most of the time you want to be working in Othrographic if yo uare doing precision modeling combo it up with the keys below...

Keypad 7 - Top view, hold shift when pressing to look at the bottom. Combo this with orthographic and possibly wireframe mode for some precision modelling.

Keypad 1 - Front view (I think), really, it's hard to tell what's truly front and side, but I'll call this view front. Hold shift and click to see the back instead.

Keypad 3 - Side view (I think), hit shift and click this to see the OTHER side, seeing a pattern here?

The keypad is going to be your bestest friend in blender, it's going to let you control your angle precisely.

Z - Wireframe view. You'll need this a lot when seeing how stuff aligns up, or selecting things that are behind other things. Unfortunately there's no fancy mnemonic to remember this one.

G - G is for GRAB, right click something, hit g, and then move the mouse until you get a position you like and then hit enter or left click. If you hit ESC you cancel this translation. You can press the x, y or z key in this mode to lock the movement to a single axis. If you use orthographic projection and the above keypad keys to set the view at a specific angle, then you can be 100% sure you're only moving something along say... the left/right and forward/back axis. If you hit G, then Z and then type in a number. It will shift the selection that many meters in that direction. And yes, that's SL meters. Everything translates to SL meters, even that grid.

R - R is for ROTATATE, right click something, hit R, and then use that mouse to spin it right rought right baby like a record baby round round.... as with above, escape cancels. Enter or left clicking sets it in stone. As with above, clever camera placement with the keypad keys can easily control which way yo uare rotating stuff. And yes, you can type in an angle after pressing R instead of moving the mouse. So R 90 ENTER, will rotate something 90 degrees with respect to whichever way the camera's facing it.

S - S is for SCALE. Right click something, hit S and move the mouse to watch it grow or shrink. Unlike the above translations, scale will happen in all directions, regardless of which way the camera is facing it. Press x, y, or z to force it to expand along a single axis only.

Shift+A - Add a new shape. If you are in edit mode, this shape will become part of whatever mesh yo uare working on. If you are in object mode, this shape will become it's own mesh, allowing you to upload to SL a multi-part-linked-mesh. Generally speaking you want the stuff under the "Mesh" menu. Curves can be handy for bending shapes or building a strange shape and extruding it, but that's something for another tutorial.

E - Lets you extrude. Highlight a face, like one of the sides of that box that blender opens up with (make sure you're in edit mode to select an individual part of an object). Once you got the face selected, hit E and drag the mouse out to watch the awesome unfold. You can even hit E and specify a distance in meters you want it to stretch out. So typing e .25 will stretch out a quarter meter of material. Word of warning: if you hit escape it will LOOK like the extrude canceled, but you'll still have a series of duplicated lines exactly stacked on top of each other. Always use CTRL+Z to undo an extrude, escape does NOT work.

Shift+D - Duplicates. It works in object mode and edit mode. In object mode it will make a new mesh exactly like the one you highlighted. In edit mode, it replicates whatever elements you selected. You'll have the option of dragging your duplicated stuff to a new home before planting it. Word of Warning: If you hit escape, like extrude, it won't cancel this. You'll end up with the duplicate exactly on top of the original. Use CTRL+Z to undo this sort of operation.

W - I like to think of this as WELD but it isn't just limited to that. It a whole list of useful options. If you select 2 or more vertecies and select merge you can collapse them upon each other, great way to clean up your mesh and remove faces. Bevel throws a bevel on whatever edges you have selected. Remove duplicates lets you clean up vertices that are exactly on top of each other (only works on hilighted selection).

N - Brings up a toolbox with a lot of useful settings. The most useful of them is a section for selecting a background image. If you play with that and set one it will only be visible if you are in one of the keypad 1 3 or 7 views. This allows you to build off of a blueprint while in orthagonal editing.

K - K is for knife which lets you cut things, make them bleed, make them hurt, also lets you get more points to move and distort your mesh. When you hit K the cursor will turn into a knife. It'll snap towards any vertices you put it near. If you hold CTRL while clicking it'll only cut on the center points and endpoints of lines, great for more precision work. After you've made all the cuts you want, hit enter to set them in stone. Hit ESC at any time to cancel.

CTRL+R - CTRL+R is for RING CUT! This is mostly handy on things like a cylinder. Ring cut doesn't like cones too much. Hit the key combo and you'll see a pink ring around the object in question. Use the mouse wheel to set how many rings you want. Click and you'll get the option to set how far up and down the object you want to drop your slices. Once you click again or hit enter you'll have a bunch more slices in your object to work with. I like to take a long cylinder. Slice some rings in it, and then indivudually select them and use the scale tool to shrink them down individually. This let's me carve a cylinder up like a lathe. I've made a real high quality baseball bat like this.