Difference between an AO and a HUD

[CherylRobinson]

I know this is a pretty stupid question to ask, but I'm confused on it. I'm relatively knew to SL, and I know what an AO is, but I've seen HUDs as well, and am not sure what the difference between the two are. Can anyone explain?

[Theresa Tennyson]

An AO, as you probably have figured out, is an "animation overrider" that changes how your avatar moves. A HUD is a "heads-up display", which is something you wear that puts some type of graphics or control on your screen that only you can see. Traditionally, most "AO"'s were attached as "HUD"'s and had their controls on your screen, which is why they might be associated in your mind, but it's possible for an AO to not be attached as a HUD and a HUD to not be an AO.

[Six Igaly]

First of all, questions never are stupid. No one can know everything :smileywink:

Ok. AO stands for animation overrider. This means you can wear a device that overrules the default avatar animations.

HUD stands for Head(s)UpDisplay. This means there is an object with buttons attached to your screen. HUDs can come with different attachments.

In this case you might have an AO that you wear on your body but is controlled by a menu on your screen, the HUD.

Hope this was clear enough for you

[Bree Giffen]

An AO is just a prim object that is scripted to replace your default animations. You can turn nearly any worn prim object into an AO like a shoe, a ring, your hair, or an invisible cube inside your body. If you put the AO scripts and animations inside a sailboat and wore that sailboat, that would work as an AO!

 

The HUD attachment points are like other attachment points on your avatar except no one else can see them on your avatar. You could attach a sailboat to a hud attachment point and no one will see it! However it will totally block your vision unless you make it a tiny sailboat. Generally, you would attach scripted prim objects like an AO to your hud points because they are more useful.

[Amethyst Jetaime]

All the above is good information.  I just want to add that AO's that use multiple animations to over ride the same animations, such as several stands, generally are controlled by a HUD to give you choices as to which animation is played and how long each lasts etc.  

Some third party viewers have built in AO controls that you can set up to take the place of a HUD.  The advantage is that the controls don't take up additional real estate on your screen since they are build into the viewer, and generally are more efficient than HUDs and contribute less to lag.  The disadvantage is that some HUDs give you a broader range of controls and choices than controls built into a viewer.  You have to refer to the particular viewers instructions for specifics, however basically you put the animations you wish to use to over ride the default animations in a folder in your inventory with a name specified by the viewers instructions, and then link them to the viewers controls as specified by the viewers instructions.

If you are shopping for and AO you can go several ways.  You can purchase an AO that uses a HUD that is preloaded with a specific set of animations that allow you to just attach and go.  You can purchase the animations individually and put them in a free HUD, or one you purchase, or in your inventory to be controlled by the viewer.  The first method is less hassle initially but also means that there are other avatars that will move the same way yours does.  However most let you add additional animations if your care to in order to make them more customized..  The second way of buying animations separately allows you to pick and choose animations to customize the over ride to better reflect your avatars personality and mix them in a way that your AO is unique to you.

Lastly, when it comes to animations and HUDs you generally get what you pay for in terms of the quality of the animation and the amount of control and number of choices that the HUD gives you. Some of the more expensive AO HUDs also make your avatar appear to breath even when it is still for a more lifelike look.  So it pays to shop around, try out a number of different animations and compare HUDs,  and buy the best that you can afford.

[solstyse]

Since you said you are new, maybe the easiest way to think about it is this.

A hud is usually some kind of interface, whether it is used for an AO, a dice rolling system, or anything else.

An AO is what changes your animations. It can have a varying number of animations, from one to whatever.

So maybe it's easiest if you compare it to a computer program. The HUD would be like all those buttons that you push to make the program do different things, but the ao is like the program itself. In a combination hud/ao, the ao is what executes the commands when you hit the hud buttons.

An ao without a hud may be menu driven when you click somewhere specific, or may be built into the viewer, and you'll have to add the animations yourself.

[Ackley Bing]

The term HUD originally comes from Aviation.

IN SL some people put their AO into a HUD, but not all HUDs are AOs.

 

[Lindal Kidd]

A HUD is an object with clickable controls that attaches to one of your on-screen attach points.  HUDs can be used to control an AO, or change the colors of your shoes, or your jewelry.  A hug and kiss attachment can have a HUD.  An SL pet can have a HUD to control it.  A language translator can have a HUD, or a vehicle may be controlled by one.

I generally have between three and five HUDs attached at any given time, each of which has a different set of functions.