[jME Tutorial 1-10] Line of Sight using the jMonkeyEngine Video Lecture | jMonkeyEngine Math: An Ultimate Guide - Game Development

sometimes you want to know if one object
can see another object such as one
character looking in the direction of
another character like if you play metal
gear solid if the enemy sees you you're
dead survivor character I want to be
able to know if a another character is
behind a wall or not so if there's no
war I want him to be able to detect that
he has saw this other character you can
create a ray from his direction in a
straight line until it hits another
geometry so in this case you want to be
able to detect you can see this man but
if there's a wall in the way for
instance then using the Rays that we
learned earlier we can shape the closest
collision we can find out that there is
a wall in the way so we we emulate that
we are not seeing this other person I'll
show you how to do that than Jamie now
you're going to create a new file
control n use the test template and to
call this line of sight I'm going to
create two spatial s 1 s 2 i'm going to
oh so it's needed to scratch my back
that's it managers model a few Sinbad
again everyone love Sinbad he doesn't
once in bed back here control shift down
to duplicate that because i'm lazy in
the best to and we need to attach this
both to the root node actual shift down
like that don't forget we need to add
our light so much here control add
control shift I
fix the imports lysis local doesn't
really matter like to do it ok ok now
I'm going to move I'll Sinbad it's a
local translation remove only ten units
to the right shift f6 to see if this has
worked for some think i'm going to make
them a bit slaughter them so it will
scale little bit small skin 0 / 5 along
each axis of look at that it's a bit too
far away from 105 chief of six that's
better okay now go to create a way which
is going to point from the scroll shift
by to fix the import subspace origin in
the direction so I'm going to take the
first Sinbad going to get this local
translation so they'll be the point of
the beginning of the array another
direction it's going to be in good to
get Lucas but not work for the local
rotation tation this one I'm going to
get rotation column 2 and that is the
direction which he faces so I'm going to
create a line using this ray I'm going
to make it 10 units long and then I'm
going to detect if that line what I'm
not going to detect if the line is going
to intersect with the second Sinbad
that's just it's just a visual
demonstration go check if the ray is 10
units
away from this in the second Sinbad and
also facing him hopefully that made
sense so I'm just going to create a
geometry for the line first of all new
geometry I need to create a new line
control shift by adult math line awad
seen shape line drove space so it will
start and an end i'm going to start it
let it go use the ray will use the break
it origin and you'll see the rain gods
get direction and i'm going to multiply
this by n scale of 10 so as the
direction is already a unit back there
that means it's going to multiply by 10
times so that its length is 10 units add
eyeshadow sublets he really all of this
to be our default material i'm also
going to change the color no I can't
leave it as white actually let's attach
this to the Midland G so I'm going to
attach the line and the direction of the
spatial is facing a shift of six
deceivers why did I do it simple update
makes no sense but ok and watches my
frames this per second goes down very
fast ok so as you can see that's a
direction is facing can get with Lance
one earth did i do this what am I even
thinking far we know actually I do need
to do this but I don't keep the line the
whole time so what I'm going to do is
each time the simple updates
groans I'll go to the church child named
line and then i'm going to create a new
line which faces that direction is
looking that will do and that we're only
have one line each time okay and now i'm
going to have sinned bad word tate so x1
tapes and then until it takes along the
y axis shift f6 and the line should
rotate with it yes ocean and weapons
there
okay now it just looks like it's fast
but okay forget me I'm seeing things
okay now I want to do or to create a
collision results object let's get
results or should I go to check if
second thin bed collide with the array
but Clyde with rain during the collision
result subject going to check if the
collision results sighs great 10 so that
means the rake lied with something as
you remember raised point to infinity so
I'm going to check if it is 10 units if
the raid it's 10 units long wait when it
collides with the second ogre so if the
size is great zero go to store the
collision result closest collision of a
more precise relation so two died
clicking result of the closest collision
patrol shift I and then if this distance
is less than 10 that means the second
ogre is 10 units
way from the first okay because you want
to be detecting a ray collision if he's
like four miles away you're not gonna be
able to see that but the ray will still
detect it if that's what you want then
you can have that patrol I'm not going
to take to these 10 meters away ah
shouldn't be hard coding up never mind
and then I'm going to make the second oh
go I'm going to turn him pink so I need
to convert it to us geometry but
hopefully I can do this I don't ride get
material set color this lieutenant pink
he has been spotted so you'll speak pink
she's closer he likes a little clean and
tidy no idea this would work long oh yes
as predicted node cannot be cast a
geometry so I'm just going to assume but
there's only one child in the nodes but
don't believe I should be any other so
they go to control shift I but I want
that one on the same mode to get child
zero convert that to a drum trio at
Shiloh something now
2 2 parameter if not defined for color
okay that's because it's unshaded so
colors for unshaded sewed when it did
the fuse car roof I'm gonna slow i'll
leave the fuse fuse I don't know I do
not know I'm just picking it up my ass
okay that didn't crash and then do
anything either Oh way is to attend
despise attendez eyes pink ah so that is
if you Childress try this one oh yes so
what you can see I'm not to completely
died god yes yes okay
and the bank ID to do anything else I'll
get rid of the line just to prove that
that is not in fact doing anything well
this makes more dramatic it's going to
be the final thing I ever do so go to s
to set material and creating it's
creating the material d facial
appearance knees and shade it again
can't go wrong with and shaded and set
color color not pink piece of still
upset material and so ID fine go I'll
just call it and want you to be safe
they pink is pink as you can yes
discussed you piece of your pic now
you piece of piece of and that is
the final tutorial I'm hungry I'm gonna
get some food