How do I know where I Am?

[Steely Dane]

I'm experimenting with placing attach points, in relation to my "Building a builder" thread.

Two problems:
1. I realize there is the object dimensions under the Object Info tab, but that seems like an awfully unweildy way of placing things, i.e. my box is 1m x 1m x 1m, so if I place my attach point on the surface of the - y axis, it will be AttachPosition  0.0 -0.5 0.0.....

2. There is nothing that I can see that indicates that my attach position is actually where I want it.
Is the idea to go back and forth into Run Game and "trial and error" it till it works, or I cut my wrists, which ever comes first?
That's not really the way we are expected do this, is it?
Or am I missing something?

[Ron]

What I have done is place the base object in a dummy world at (0,0,0) and then load the attachment object into that world too. You can then move it around to where it needs to be and note the coordinates in the engine and use that for your attachment point.

[Steely Dane]

Zam! that was quick!
Well, while I stepped out to put my laundry in the dryer, it occured to me that I could figure out the coordinates I need for attach points in my Modeler, but I was experimenting with the actual box primitive supplied in GC.

I'm guessing that my solution for problem 2 is the correct one.
Seems like a small oversight not to have some sort of an indicator show up in the editor that your attach point is where it should be....

[Squat]

I seriously need to be corrected here because I'm almost certain that I'm wrong, but I could of sworn we had the ability to add anchors to our models upon export. These are dummy objects which contain only position/rotation/size data and would be able to be named. This would effectively completely eliminate the need for messing around with any kind of coordinates. Let's face it, if you really do have to note coordinates and you want to put together this giant puzzle of pieces that attach to pieces that attach to pieces, you're screwed. If we don't have the option of exporting dummy anchors with our objects, we really need to have that implemented so we can do it. Again, I thought we actually had that ability.

I do know a workaround because I know that we can attach certain things to particular bones (by name) as I put a tennis ball on one of my rat's feet and it followed the animation and everything. So include some named bones that act as the attachment points and it should automatically align the attaching object right to it and even follow the animations perfectly.

[Steely Dane]

That was basically what I was asking. I'm not sure, so I was hoping one of you Guru's could confirm that I was missing something.

Exactly....although I wouldn't say totally screwed, but definitely bent over.
I'm not exactly sure I understand the   "add anchors to our models upon export. These are dummy objects which contain only position/rotation/size data and would be able to be named." 
Could you explain this to me. Where do I find these options.

Actually my workaround that I was considering was to just make all of the models so that the attach points line up to 0.0 0.0 0.0 in my modeler, then import them into the editor and assign the attach point there. The only time it could get tricky is with an object with many attach points (like a main object).

[Squat]

Well, I'm speaking strictly about 3D Studio Max, but it has several types of dummy helpers, which are basically just pivot points...or origins. In Max, you can add dummies or point helpers and they're essentially the same thing.

Here's an example, I have my rat set up so that there is a box which is positioned next to his hands and named "weaponmarker" (to coincide with the original character .opr)...ok, this reminds me that this is totally possible and the way to go...lol. Anyway, this box is textured in GC as completely transparent. Whenever I add a weapon to the rat's inventory, I attach it to the weaponmarker object and it follows it perfectly.

When I set up my animations, I actually put the gun into the scene and animate it with the gun attached to that same box, but I do not export the weapon itself in any way, except when I export the basic model.

I've worked with previous character rigs that actually include up to 16 dummy weapon object "boxes" and this enables the ability to animate the weapon in multiple pieces such that the magazine can be removed, the trigger can be pulled back and even the bullets themselves can be animated. That example required the weapon export to be named to coincide with that dummy object system, so the weapon and its parts were named mesh1, mesh2, mesh3....etc.

I hope this is making more sense, if not...I'll stop here anyway.

[Steely Dane]

Ah, ok, i thought you meant GC had this kind of option.

In Lightwave modeler, there is indeed a way to set your pivot points anywhere you want, and in Layout you can add null points, but I doubt that would be of any use, as I don't think they export into GC, and the pivot points basically just adjust where the center of mass is on the object (and each object can only have 1 pivot point).

With Lightwave, a 1 polygon mesh as a "dummy" marker might be the way to go, for me.
If I understand you correctly, that would make the "attaching" object actually attach to the transparent poly, which is loaded as a separate object that doubles up on the original poly of the main object, if that makes any sense at all. Not exactly the same as your solution, but a variation on the theme to fit my 3D package.
Guess I'll put the razor down now, lol..........

Thanks for input, that totally helped.

In fact, I could go one better and make the poly semi transparent and slightly illuminated, which was also on my wish list. Then it would be as simple as it switching off when a piece is attached to it, and also allows me to color code it so you know which accessories can attach to it.

[Squat]

Yeah, you can basically use any shape mesh you want as your marker objects and have them glow or pulse or something while they're empty and then hide them when they're occupied. Could be as simple as having it glow red should the user attempt to attach the wrong piece and make it green when it will fit. Lots you can do. The marker object will have it's own pivot location and translation so technically speaking you can have as many as you like and there's no real worry about a complex mess of pivot alignments or lists of coordinates. The attaching objects, or accessories, would still probably need to have their pivots aligned to the world's 0,0,0 in your modeler, but they too can have a bunch of marker objects for further additions down the chain.

[Ransom]

The easiest way to make your attachment point is to give the model a joint in your 3D app.  You can then setup the OPR to recognize the joint and use it to attach the other objects.  Different attachment objects will most likely require different offsets from the joint, so you'll want that info to be in the attachment object's OPR, not the main object's.

[Steely Dane]

@Squat:
Exactly, it is a pretty ingenius way of doing it, and I thank you for the suggestion!
Also not terribly difficult to do (easy actually).

@Ransom:
I'm not sure what you are getting at with adding a joint in my 3D app. As far as I know, there is no add joint function in Lightwave.
Perhaps if you describe what you mean I can translate it into Lightwave-ese (I'm not being sarcastic, just that some of the functions that other apps have are called something else in LW, or just don't exist).

[Ransom]

Milkshape calls them joints.

many other apps call them bones.

Basically, a rig for the model, though you won't be using it for animation, just reference points and thus don't even need to attach the bones to any particular vertice.

[Steely Dane]

Yeah, they are bones in LW...it would actually be just as easy, maybe even easier to do it the way I'm going to do it (transparent poly's)...

[gekido]

I would highly suggest you check the 'modular weapons' tutorials I've been writing on the Combat Spec Ops blog.

These two in particular goes into what you are talking about:

Basics of using Attach Points & so on:
http://www.combatspecops.com/2009/08/modular-weapons-phase-2/#more-543

'How' I'm setting up the modular system itself:
http://www.combatspecops.com/2009/09/the-art-science-of-modular-weapons/

Now when it comes to attach points, there are a number of options:

1) simply manually type positions / coordinates like you have done

2) add bones to the moel - note that the cool part about this is that the bone rotation is taken into account as well, so I can setup an attachment that will align properly with the parent model irregardless of where it is attached.

3) use the AddNullObject OPR property to specify the attach point, but this is basically the same as #1

For example, here's a shot of the 'base' M4 model showing it's attach points:



And the final M4 with an FN-SCAR that was setup using the same system.  Maximum reuse of content == good ;]

[Steely Dane]

Beat you to it, dude!
I just happened to wander over there to see if, and what I was missing in your blogs, and lo and behold what did I find? A sweet little blurb covering exactly what I was looking for.
So you would recommend using bones for aligning my attach points?
After some reconsideration, I do have to agree, in that it would greatly simplify the process, and I won't have to load all these stupid 1 point polygon models to every asset with attachment points I'm using.
Not too bright on my part, but I'm learning......

Incidentally, your system is identical to what I was trying to achieve, with the only difference being that I want to be able to click on the optional pieces with my mouse and drag and drop them into place instead of choosing them beforehand, while being able to turn the model on it's axis in the viewport in all directions, by using the mouse.....or something like that.