is a vertex in a certain space? [~SOLVED]

[kiriri]

 So I'm currently working hard on a set of decal functions . So far I've got a projecting mesh one which creates vertices by ray collision , and a project simple plane decal. However, I want a very accurate one which will be able to create multiple split parts of a decal if it hits multiple meshes, and I also need one that will properly work on skinned meshes. I'm close to finishing those too, but there's one hindrance:

So far I've used a lot of playmaker stuff as references, but I couldn't find a way to determine whether a certain vertex (or vector 3 (point)) is within a 3 dimensional cuboid (between 3 vector3 ) .

The reason why I'm asking here first is so that I know whether I should implement it as an action after I found a way. So far I'm considering something like the algebra 3 way I remember from school:
vec0 + s*vec1 + r*vec2 + t*vec3 = VecPoint
if r,s,t less than 1 and greater than 0, the point is in the cuboid, else it is not. (the vectors are not normalized)

I haven't been able to find a way to auto-calculate  r , s and t though.
If this is not possible yet, let me know please, so I can add it as an action (Though I'm not quite sure how to :S )

[jeanfabre]

hi,

 I would go for a much simpler approach, using Unity Bound class and api.

http://unity3d.com/support/documentation/ScriptReference/Bounds.Contains.html

You basically create a bound class, and then use the function contains to find out if a point is within this bound.

Knowing this, its then easier to work with, and no math nor vector math involved

 If you have problems wrapping this into a custom action, try using the playmaker custom action wizard in the playmaker tool menu, else simply duplicate one of the standard action in the playmaker/action folder to use as a base.

If you still have issues, let me know, I'll make it so that you can see how to approach such custom action.

bye,

 Jean

[kiriri]

seriously, that was too simple Thanks a lot, I don't think I'll be needing any help to create an action for this
Do you know how expensive this function is? could it be used per frame without any worries?

... now that I thought so hard about it, I wonder how that function is defined...

[kiriri]

oh, I just noticed a problem, how would I be able to construct a bounding box which is not aligned to the axis? Like one that goes diagonally:
width : 1/2/0
length : 2/-1/0
height : 0/0/1
origin : 0/0/0
like that?

If that's not possible then that's not all that bad either, I could always use multiple bounding boxes for each collision, though that's slightly inaccurate... or I could rotate the bounding box to the vector of the ray... (EDIT) which I just found out is not possible... meh, why is stuff always this hard?

EDIT: I'll write my own function, I found a 2D function already, can't be too hard to make it 3D.

[jeanfabre]

Hi,

 If your cuboid is not aligned with the world, then I would strongly suggest you simply use a radius for searching. and instead of defining a box to find if a point is within that volume, define a sphere, which is basically just a radius, and define your radius as a power of two so that you simply extract the square magnitude of your point against the center, which is a lot more efficient than getting the magnitude ( because of the squre root operation)

 Bye,

 Jean