Replacing "Body Part" Primitives

There are two basic shapes in Second Life: male and female. We can clothe them, change their colors, size, we can squeeze and stretch them, and pull all sorts of neat tricks. What I want to do is learn how to make new "basic" shapes, or at the very least how to replace the primitives that make up "body parts" with other primitives or linked primitives. Just to start out with I want to see if I can make an avatar that's a bouncy ball, a simple sphere with bounce-like animations to walk, perhaps the sphere rolls when you run, and flattens out when you crouch, and does that sort of thing. After that I hope I can make more complex avatars than just a floating sphere.

It would be really nice if there was a step-by-step out there how to do something simple like this, and I'd like to put it together. But until I manage to figure out how to change/add/remove/hide the primitives that make up my avatar's shape, I hope you can help me move towards that goal.

I did this, it's a great av -- when I type, you can follow the bouncing ball. You can't do it the way you think, though: you have to use a "meatball" animation to crunch the Linden av as small as possible, and then use prims to build your new av around it. It is not possible to make new av shapes and use them as your avatar directly, in the sense that the Linden Poser models are.

Think of the avatar as a "Mesh" or "Spline Patch"... it's deformed, it's shaped, but it's a wafer thin piece of fabric stretched over various coordinates.

Now think of Primitives as solid blocks of wood. The Avatar has a single prim, it's evidently a stretched sphere, and it's invisible. That's the Agent, and the Agent is Physical, and solid. The Avatar is phantom.

You can attach prims to the avatar's skeleton... but you can't replace the mesh. There's no mechanism in the SL universe for uploading meshes. (though how I wish there was). The primitives (solids) technically are made of meshes as well.. but for purposes of SL, they're Solids.

Wireframe modelling vs Solid Modelling.

The solution most people use is to squish the avatar into ultra-thin, and often ultra small parts... and then attach prims that either completely enclose the body part in question, or augment it, altering the overall appearance of that body part. A third option uses an "invisiprim" to actually "clip away" parts of the mesh. Not actually.. but parts of the mesh can be made invisible. Making it possible to make holes and openings into cavities within the mesh.

Oh, excellent. That explains the technical problem with it then. We can't upload our own custom cube shape, but instead have to use the cube shape SL provides and deform and link it according to the methods SL allows us to use. In the same way (if I understand correctly) we can't upload our own custom avatar shape, but instead have to use the male or female shape SL provides, and deform and link it according to the methods SL allows us to use.

From a bandwidth standpoint I guess it makes sense not to be transferring meshes around. But on the other hand I wonder how the size of a relatively complex mesh like an avatar shape would correspond to the size of a relatively complex texture. Surely it can't be larger than those unbelievable streaming Quicktime movies. Anyway, I understand the issue.

Heh... I can imagine the chaos that would ensue if we were allowed to treat the sphere/cube/etc shapes equally with the male/female avatar shapes. The residents would be making fortifications out of the bodies.

They're solid blocks of wood, provided you select wood as your material type. I suppose then by "Agent" you mean the "avatar shape" I've been talking about? It's very black box, the physics of SL: I can tell that each SL object has two 3D blobs, one to display stuff on (the phantom), and one to calculate physical collision, the latter of which is always invisible and hard to pin down exactly what it's shape is.

That would make sense. I haven't explored yet how extremely we can shorten arms/torsos and the like. I didn't think it was possible to squish them to ultra small levels, but I guess that's a wrong assumption.

This last one, how does one "use" an invisiprim? I got my hands on one the other day, but attaching it to a body part just stuck a cube on the end of that body part, so clearly that's not how you do it.

By the way, there is really only one avatar Mesh - the female. Males are a morph applied to the female avatar, that changes the base setpoint that the sliders in the appearance controls start from.

Invisiprims are on my twisted mind today. A friend and I picked up a load of avatars and when I was switching into one I could see how the invisiprim first essentially erased me before the other prim attachments were applied. Is it that the invisiprim just hides the avatar mesh and not the other prims? I would think if it protruded through them you'd end up with holes there as well.

Just trying on all those avatars has given me so much inspiration!!

Audio and Video streams don't go through the LL servers, they're sent directly to the client viewers from the URL(s) specified in parcel media properties, so those don't have a performance impact on the SL environment at all.

Lots of information on making custom avatars (including invisiprims) at Avatar Toolbox.

Invisi prims are prims that, through a script, have a texture applied that hides all avatar meshes, 32 bit textures (transparent or not) as well as making prims with shiny look as they didnt have shiny at all. It might also have a bit of an effect on colors. other than that everything is ignored and the invisi prim renders just like a normal 100% transparent prim.

Just like any other prim. and invisi prim is just a regular prim with a script that applies set of particular properties through a texture not available through other means. that texture has the effect of defining what is rendered and what isn't when seen through it. Avatar meshes, 32 bit textures (with or without transparency, curse those who submit textures without any transparency as 32 bit) are hidden. Shiny isn't rendered through invisi prims though the prim itself is. It might also have some effect on the colors of things (makes them get slightly faded at times). But an invisi prim is still a regular prim so you use it just like any other prim and you can cut it too.

That's cool. So I could use one as a tool to weed out the 32-bit textures I probably created when I didn't know any better.