1
00:00:00,510 --> 00:00:01,470
Welcome back.

2
00:00:01,470 --> 00:00:07,710
In this lecture we're going to be learning about a fundamental feature in Roblox studio called Ray casting.

3
00:00:07,740 --> 00:00:15,840
Ray casting is this idea of shooting an invisible ray in a defined direction with a defined distance,

4
00:00:15,840 --> 00:00:20,490
and checking to see if that ray hit any 3D object in our workspace.

5
00:00:20,790 --> 00:00:26,820
To be able to perform a raycast, we first need an origin point and a direction that defines where we

6
00:00:26,820 --> 00:00:30,420
want to shoot a ray from with respect to that origin point.

7
00:00:31,130 --> 00:00:36,380
A cool way for us to demonstrate Raycasting would be creating a simple tool, and every time the player

8
00:00:36,380 --> 00:00:42,110
clicks the tool, we're going to fire a ray pointing towards wherever that tool is looking, and then

9
00:00:42,110 --> 00:00:45,980
we'll check to see if that ray hits any object in our workspace.

10
00:00:45,980 --> 00:00:49,310
So we're going to create a new tool in the starter pack.

11
00:00:50,040 --> 00:00:53,430
And I'm just going to call this tool Raycast tool.

12
00:00:54,550 --> 00:00:59,140
And then for the handle for this tool, I'll just create a new part inside of my tool.

13
00:00:59,140 --> 00:01:02,920
I'll call it handle and I'm going to make it a little bit smaller.

14
00:01:02,920 --> 00:01:09,970
So I'll just uh, I'll just have the dimensions be a cube of 0.5 by 0.5 by 0.5 studs, and then we'll

15
00:01:09,970 --> 00:01:12,580
make sure can collide is turned off for this handle.

16
00:01:12,580 --> 00:01:14,440
And we'll make sure it's unanchored as well.

17
00:01:14,830 --> 00:01:19,510
And then inside of here we can go ahead and create a server script to listen to the events for this

18
00:01:19,510 --> 00:01:20,140
tool.

19
00:01:20,970 --> 00:01:22,980
So I'll make a reference to my tool.

20
00:01:22,980 --> 00:01:24,240
Create a variable called tool.

21
00:01:24,240 --> 00:01:26,550
And that's just equal to script dot parent.

22
00:01:26,550 --> 00:01:31,170
And then I'll also make a reference to my handle and let's say child of my tool.

23
00:01:32,090 --> 00:01:38,870
And then what we could do is when the tool is activated by a player, we can go ahead and shoot a ray

24
00:01:38,990 --> 00:01:43,190
in the direction of wherever our handle is facing in our tool.

25
00:01:43,890 --> 00:01:45,120
To fire a ray.

26
00:01:45,120 --> 00:01:51,000
In our game, we use a function underneath the workspace of raycast and as you can see it says this

27
00:01:51,000 --> 00:01:57,120
function takes an origin point, a direction as well as some optional raycast parameters, and it says

28
00:01:57,120 --> 00:02:01,440
casts a ray using an origin direction and an optional raycast parameters.

29
00:02:01,440 --> 00:02:06,960
Then returns a raycast result if an eligible object or terrain intersects the ray.

30
00:02:07,590 --> 00:02:13,260
Here in the Roblox documentation, we can see that a raycast result is a custom data type, and it says.

31
00:02:13,260 --> 00:02:18,300
This data type stores the result of successful Raycasting operation performed by World Route, which

32
00:02:18,300 --> 00:02:21,090
would be the workspace and the raycast function.

33
00:02:21,090 --> 00:02:26,040
And inside of this data type it stores some properties such as the distance it says, the distance between

34
00:02:26,040 --> 00:02:30,570
the ray origin and the intersection point, the instance that was hit.

35
00:02:30,570 --> 00:02:34,110
So that would be the base part or the terrain that the ray intersected.

36
00:02:34,110 --> 00:02:36,870
There would be the material at the intersection point.

37
00:02:36,870 --> 00:02:43,680
It gives us the position where this ray hit an object, as well as the normal and the normal vector

38
00:02:43,680 --> 00:02:45,120
of the intersected face.

39
00:02:45,120 --> 00:02:51,750
And the normal vector is basically just what direction is forward for whatever part's face it hit.

40
00:02:51,750 --> 00:02:59,040
So if it hit one side of a part, then the normal or the direction that that face is looking towards

41
00:02:59,040 --> 00:03:01,950
would be this normal property right here.

42
00:03:02,760 --> 00:03:07,770
We can also go ahead and take a look at the raycast parameter data type and it says the raycast parameter.

43
00:03:07,770 --> 00:03:12,960
Data type stores parameters for the raycast function and it has some properties down here.

44
00:03:12,960 --> 00:03:19,290
This is an array called Filter Descendants instances, and we would pass a table or an array of objects

45
00:03:19,290 --> 00:03:25,200
whose descendants are used in filtering raycast candidates, and we choose this by setting the filter

46
00:03:25,200 --> 00:03:28,200
type with an enum raycast filter type.

47
00:03:28,200 --> 00:03:35,640
So we would either include or exclude these certain objects from the raycast operation if we include

48
00:03:35,640 --> 00:03:36,060
them.

49
00:03:36,060 --> 00:03:41,700
That means this raycast is going to ignore every single object in our game, except for the objects

50
00:03:41,700 --> 00:03:44,550
within our filter descendants instances array.

51
00:03:44,550 --> 00:03:51,090
And if we set the filter type to exclude, then the raycast is going to include every object in our

52
00:03:51,090 --> 00:03:54,930
game except for the objects that are inside of this array.

53
00:03:55,200 --> 00:03:57,750
We also have some additional properties here, such as.

54
00:03:57,750 --> 00:03:59,790
If we would like the ray to ignore water.

55
00:03:59,790 --> 00:04:04,830
We can also set a collision group that we would like the raycast to include or exclude.

56
00:04:04,830 --> 00:04:10,020
There's another property here called respect can Collide and it says determines whether the raycast

57
00:04:10,020 --> 00:04:14,880
operation considers a parts can collide property over its can query value.

58
00:04:14,880 --> 00:04:18,840
And every single part in your game has this property called can query.

59
00:04:18,840 --> 00:04:26,520
And this property allows you to basically select which parts in your game are included or excluded in

60
00:04:26,520 --> 00:04:27,990
raycast operations.

61
00:04:27,990 --> 00:04:33,900
Any parts in your game that have the can query property set to false will not be included in any raycast.

62
00:04:33,900 --> 00:04:36,390
And then this last one here is called Brute Force.

63
00:04:36,390 --> 00:04:42,630
All slow and it says when enabled, the query will ignore all part collision properties and perform

64
00:04:42,630 --> 00:04:45,090
a brute force check on every single part.

65
00:04:46,320 --> 00:04:47,640
Back in studio.

66
00:04:47,640 --> 00:04:53,670
Whenever our player activates this tool, we want to go ahead and shoot a ray from an origin point,

67
00:04:53,670 --> 00:04:59,550
which would be the position of our handle in a direction which would be wherever our handle is facing.

68
00:04:59,970 --> 00:05:02,100
So we can call our raycast function.

69
00:05:02,100 --> 00:05:06,540
And that means we need to pass the origin direction and optional raycast parameters.

70
00:05:06,540 --> 00:05:09,060
So let's go ahead and create two variables.

71
00:05:09,060 --> 00:05:14,880
One variable is going to be my origin, while the other variable is going to be my direction.

72
00:05:15,450 --> 00:05:18,210
So for the origin this one's going to be very simple.

73
00:05:18,210 --> 00:05:21,870
The origin is going to be my handles position in the workspace.

74
00:05:21,870 --> 00:05:23,970
So we just get handle dot position.

75
00:05:23,970 --> 00:05:26,520
This is where we would like the ray to start at.

76
00:05:26,520 --> 00:05:31,560
And then the direction is going to be whichever way our handle is facing.

77
00:05:31,560 --> 00:05:37,080
And to get the look vector of our handle we can reference our handle keyframe.

78
00:05:37,080 --> 00:05:40,110
And our keyframe stores the look vector property.

79
00:05:40,110 --> 00:05:45,330
And that returns the forward direction component of the keyframe object's orientation.

80
00:05:45,330 --> 00:05:49,680
So this will basically tell us where our part is looking as an example.

81
00:05:50,470 --> 00:05:55,660
If we take a look at this part right here, and we right click our part and we press Show Orientation

82
00:05:55,660 --> 00:06:03,040
indicator here, it shows us the look vector for this part, which is on this front facing side of our

83
00:06:03,040 --> 00:06:03,490
part.

84
00:06:03,490 --> 00:06:07,360
And that is the direction or the look vector for this part.

85
00:06:08,330 --> 00:06:13,550
Now that we have our origin and our direction, we can go ahead and pass the origin and then we can

86
00:06:13,550 --> 00:06:15,440
also pass the direction.

87
00:06:15,470 --> 00:06:20,330
Now this direction also needs to include a length or a magnitude.

88
00:06:20,330 --> 00:06:26,870
And as you can see it says note that the length of this vector matters as part trains further away than

89
00:06:26,870 --> 00:06:28,730
its length will not be tested.

90
00:06:28,730 --> 00:06:35,120
So this is where you would multiply this vector by a value, which would indicate how long you would

91
00:06:35,120 --> 00:06:37,070
like this direction to be.

92
00:06:37,070 --> 00:06:42,230
For example, if I multiplied this direction by the value of ten, then my direction is going to be

93
00:06:42,230 --> 00:06:43,940
ten studs in length.

94
00:06:43,940 --> 00:06:49,610
So this is going to fire a ray up to ten studs away from me, and then it's going to stop and ignore

95
00:06:49,610 --> 00:06:51,260
anything else further away.

96
00:06:51,260 --> 00:06:55,370
If I want it to shoot farther than that, I could enter a value like 500.

97
00:06:55,370 --> 00:07:02,450
And now my direction is going to basically fire a ray 500 studs away from me, and this ray will stop

98
00:07:02,450 --> 00:07:05,420
once it hits a part in our workspace.

99
00:07:05,930 --> 00:07:09,290
So for this demonstration, we'll just put it at 100 studs.

100
00:07:09,530 --> 00:07:13,400
And of course this function is going to return to us a raycast result.

101
00:07:13,400 --> 00:07:15,740
So we'll create a variable and we'll just call it result.

102
00:07:16,620 --> 00:07:19,890
Now we're also going to go ahead and take a look at raycast parameters.

103
00:07:19,890 --> 00:07:25,080
So outside of my activated event I'm going to create a variable called params.

104
00:07:25,140 --> 00:07:27,510
And that's going to be equal to a new raycast parameter.

105
00:07:27,510 --> 00:07:29,580
So we refer to raycast params.

106
00:07:29,580 --> 00:07:32,550
And then to create one we use the new constructor.

107
00:07:32,880 --> 00:07:38,040
And then from here we have access to all of those different properties inside of this data type, such

108
00:07:38,040 --> 00:07:42,810
as filter descendant instances, the filter type and some other settings as well.

109
00:07:43,320 --> 00:07:51,390
If we would like to exclude some different items from our raycast and we can set the filter type equal

110
00:07:51,390 --> 00:07:55,230
to the enum dot raycast filter type dot exclude.

111
00:07:55,230 --> 00:07:59,040
This used to be blacklist, but for some reason they deprecated it.

112
00:07:59,040 --> 00:08:01,740
As you can see it is um.

113
00:08:02,480 --> 00:08:03,680
Has a strike through through it.

114
00:08:03,680 --> 00:08:04,910
So that means it's deprecated.

115
00:08:04,910 --> 00:08:10,430
I don't know why they deprecated Blacklist and Whitelist and replaced it with exclude and include,

116
00:08:10,430 --> 00:08:11,840
but it's whatever.

117
00:08:11,840 --> 00:08:15,200
So we use exclude now instead of blacklist.

118
00:08:15,590 --> 00:08:22,070
Then every time we activate the tool, some things that we want to go ahead and ignore from this raycast

119
00:08:22,070 --> 00:08:24,830
would be for example, our player's character.

120
00:08:24,830 --> 00:08:30,080
We don't want to intersect with anything on our player's character, and we certainly don't want to

121
00:08:30,080 --> 00:08:36,290
intersect with the handle that the ray is going to be firing from, because that'd be kind of stupid.

122
00:08:36,290 --> 00:08:43,460
So what we can do is we can go ahead and update the parameters dot filter, descendent instances equal

123
00:08:43,460 --> 00:08:44,660
to a new table.

124
00:08:44,660 --> 00:08:48,650
And this table is going to contain the parent of our tool.

125
00:08:48,650 --> 00:08:53,840
And since this tool can only be activated when it's equipped, that means the parent of our tool is

126
00:08:53,840 --> 00:08:55,880
going to be a player's character model.

127
00:08:55,880 --> 00:08:58,610
And that character model includes this tool.

128
00:08:58,610 --> 00:09:05,450
So this tool is going to be exempt from our raycast as well as any descendants or 3D object descendants

129
00:09:05,450 --> 00:09:06,950
of our player's character.

130
00:09:07,660 --> 00:09:13,210
Now we can go ahead and pass our raycast parameters to our raycast function to be included in our raycast

131
00:09:13,210 --> 00:09:14,050
operation.

132
00:09:15,580 --> 00:09:20,620
Now this is going to fire a ray inside of our workspace, and it's going to check to see if it hits

133
00:09:20,620 --> 00:09:21,310
anything.

134
00:09:21,310 --> 00:09:23,740
And that's going to be returned in this raycast result.

135
00:09:23,740 --> 00:09:28,120
So we can go ahead and check if this function actually returns something.

136
00:09:28,120 --> 00:09:32,920
Because if this raycast didn't hit anything, then the function is going to return nil.

137
00:09:33,220 --> 00:09:38,260
So we can check to see if we hit something by checking to see if there's a value stored in result.

138
00:09:39,170 --> 00:09:42,260
And if there is, then we can go ahead and print that.

139
00:09:42,260 --> 00:09:43,820
We hit an instance.

140
00:09:43,820 --> 00:09:49,160
And this result of course stores some information, for example, the instance that we hit.

141
00:09:49,160 --> 00:09:52,130
So we can get the instance and then the name of the instance.

142
00:09:52,130 --> 00:09:54,980
So we can print that we hit this particular instance.

143
00:09:54,980 --> 00:09:58,310
And then we can also print out what position we hit this instance.

144
00:09:58,310 --> 00:10:00,020
So I'll say at position.

145
00:10:00,020 --> 00:10:03,260
And then we can pass the results dot position.

146
00:10:04,250 --> 00:10:09,590
Otherwise, if there is no result, that means our raycast did not find any 3D objects in our workspace

147
00:10:09,590 --> 00:10:14,030
to hit, so we can print something like the ray hit nothing.

148
00:10:16,290 --> 00:10:19,770
So now let's go ahead and playtest our game and see what happens.

149
00:10:21,040 --> 00:10:23,560
So here is my raycast tool and my part.

150
00:10:23,560 --> 00:10:29,200
And this should shoot a ray out from this face of my part in that direction.

151
00:10:29,200 --> 00:10:30,250
100 studs.

152
00:10:30,250 --> 00:10:35,140
If it hits anything then it'll print what it hit, otherwise it should print nothing.

153
00:10:35,170 --> 00:10:39,010
So if I turn and face this part and then I were to click.

154
00:10:39,280 --> 00:10:45,190
As you can see, it says we hit an instance part at position, and then it gives us the exact position

155
00:10:45,190 --> 00:10:47,650
where the ray intersected with the part.

156
00:10:47,680 --> 00:10:51,040
We can also click over here or click here.

157
00:10:51,040 --> 00:10:56,200
But if we face away from our part and then we shoot, as you can see, the ray hit nothing because there's

158
00:10:56,200 --> 00:10:58,870
nothing in front of us for the ray to intersect.

159
00:10:59,750 --> 00:11:05,750
Now we can also go ahead and visualize this raycast by creating a part, and then positioning that part

160
00:11:05,750 --> 00:11:13,520
between our origin point and the hit point, and then increasing the length of our part to represent

161
00:11:13,520 --> 00:11:16,310
the total distance of the raycast.

162
00:11:16,310 --> 00:11:18,080
So let's go ahead and do that.

163
00:11:18,080 --> 00:11:23,780
If we get a result from our raycast, then what we can do is we can create a new part.

164
00:11:26,160 --> 00:11:33,150
And the size of this part is going to be equal to a new vector three and for the x size, we need it

165
00:11:33,150 --> 00:11:34,890
to be 0.05.

166
00:11:34,890 --> 00:11:38,220
And for the y size we also need it to be 0.05.

167
00:11:38,220 --> 00:11:44,700
And the z is going to be the length or the distance between the origin point and the hit point from

168
00:11:44,700 --> 00:11:46,530
our result data type here.

169
00:11:46,770 --> 00:11:50,940
So this is going to be equal to the result dot distance.

170
00:11:51,880 --> 00:11:58,330
And the reason we have to do it on the Z axis is that if we take a look and we create a new part here.

171
00:11:59,330 --> 00:12:02,060
And we were to show the orientation indicator.

172
00:12:02,060 --> 00:12:04,160
So this is the front of my part.

173
00:12:04,160 --> 00:12:10,520
And if we were to resize this part, as you can see, the area we need to resize is the z axis when

174
00:12:10,520 --> 00:12:12,170
this part faces an object.

175
00:12:12,170 --> 00:12:19,820
And that's because we need to set the keyframe of this part to be facing towards wherever we hit, and

176
00:12:19,820 --> 00:12:21,980
that way it's accurate and it looks correct.

177
00:12:21,980 --> 00:12:29,270
So if we were to set the size to be 0.05 and 0.05 and then like ten, then this is what our array is

178
00:12:29,270 --> 00:12:30,320
going to look at.

179
00:12:30,320 --> 00:12:35,180
And this part is basically going to visualize where our ray hit in the workspace.

180
00:12:35,180 --> 00:12:40,580
It's going to look towards where we hit and it's going to orient itself correctly.

181
00:12:40,580 --> 00:12:47,360
We can imagine this end as the origin point and this end as the point of where we intersected a part.

182
00:12:47,390 --> 00:12:49,460
This is what our array is going to look like.

183
00:12:50,640 --> 00:12:53,280
Once we set the size, we can go ahead and change the color.

184
00:12:53,280 --> 00:12:55,080
I'll just make it completely white.

185
00:12:55,080 --> 00:12:58,470
So we'll do from RGB and we'll create.

186
00:12:58,470 --> 00:12:59,130
It's already white.

187
00:12:59,130 --> 00:13:00,240
So we'll just do that.

188
00:13:00,660 --> 00:13:02,490
We'll make sure the part is anchored.

189
00:13:02,490 --> 00:13:05,310
And we'll also make sure that can collide is false.

190
00:13:05,310 --> 00:13:06,420
So we don't hit it.

191
00:13:06,840 --> 00:13:10,890
And now we need to go ahead and update the keyframe of our part.

192
00:13:10,890 --> 00:13:12,540
And this is going to be simple.

193
00:13:12,540 --> 00:13:15,780
All we need to do is use the keyframe dot lookup function.

194
00:13:15,780 --> 00:13:21,360
And remember this returns a keyframe with a position of the first vector and an orientation pointed

195
00:13:21,360 --> 00:13:22,440
towards the second.

196
00:13:22,440 --> 00:13:28,530
So we're basically positioning this part to be at the origin, and we want it to look at wherever we

197
00:13:28,560 --> 00:13:30,960
hit, which would be the result dot position.

198
00:13:30,960 --> 00:13:36,180
So now our part is going to be looking towards this position from the origin point.

199
00:13:36,850 --> 00:13:42,820
Now, since the pivot of our part is directly in the center, for example, that is our central pivot

200
00:13:42,820 --> 00:13:43,780
point of the part.

201
00:13:43,780 --> 00:13:46,030
It's not at the end or over here.

202
00:13:46,030 --> 00:13:51,370
That means we need to account for the fact that the pivot is in the center of our part.

203
00:13:51,400 --> 00:13:56,920
So we need to move this part by half of the distance.

204
00:13:56,920 --> 00:14:03,250
So that way it's perfectly positioned between the origin point and the point at where we hit.

205
00:14:03,940 --> 00:14:07,630
To visualize this, you can basically think of this black dot right here as our player.

206
00:14:07,630 --> 00:14:10,060
And then this red dot is our origin point.

207
00:14:10,060 --> 00:14:12,070
And this other red dot is where we hit.

208
00:14:12,070 --> 00:14:13,630
And you can imagine this as another part.

209
00:14:13,630 --> 00:14:16,780
So the player fired a ray towards this direction.

210
00:14:16,780 --> 00:14:17,890
And we hit right here.

211
00:14:17,890 --> 00:14:22,360
And we want to get the position between these two points the half way mark.

212
00:14:22,360 --> 00:14:28,780
So that way we can accurately set the keyframe of our part to be perfectly between these two parts.

213
00:14:29,020 --> 00:14:34,630
If we didn't account for this offset, then our part would instead look something like this, where

214
00:14:34,630 --> 00:14:40,360
the central point of our part would be next to our origin point, it would look incorrect, so we need

215
00:14:40,360 --> 00:14:48,400
to offset it by whatever half the distance is between our origin point and our hit point.

216
00:14:50,120 --> 00:14:51,770
And that's very easy to do as well.

217
00:14:51,770 --> 00:14:57,140
All we need to do is add a new keyframe and remember to add a keyframe to another keyframe.

218
00:14:57,140 --> 00:15:01,130
We have to use the multiplication symbol and not the addition symbol.

219
00:15:01,130 --> 00:15:07,010
The addition symbol is when you offset it using vectors, and then the multiplication symbol is when

220
00:15:07,010 --> 00:15:09,170
we offset it with another keyframe.

221
00:15:09,170 --> 00:15:11,600
So we'll create another new keyframe here.

222
00:15:11,600 --> 00:15:18,530
We don't need to offset it on the x axis or the z axis, but we need to offset it on the z axis, because

223
00:15:18,530 --> 00:15:21,230
that's the direction where the look vector is.

224
00:15:21,230 --> 00:15:28,310
And that z offset, remember, is going to be half the distance of result dot distance.

225
00:15:28,310 --> 00:15:32,720
So we'll just pass result dot distance and then divide it by two.

226
00:15:32,720 --> 00:15:37,760
And then in order to make sure that this offsets in the correct direction we actually need to negate

227
00:15:37,760 --> 00:15:38,750
this value.

228
00:15:39,080 --> 00:15:42,320
So basically shifting the position of this part.

229
00:15:42,890 --> 00:15:49,940
From the origin point to the point between the origin and the position of where we hit.

230
00:15:50,600 --> 00:15:55,820
And then once we do that, we can finally set the parent of our part equal to the workspace so we can

231
00:15:55,820 --> 00:15:57,260
actually see it in our game.

232
00:15:57,560 --> 00:15:59,390
So now if we go and play test.

233
00:16:00,500 --> 00:16:02,480
If I were to look away and I clicked.

234
00:16:02,480 --> 00:16:04,160
As you can see, the ray hit nothing.

235
00:16:04,160 --> 00:16:07,220
But if I turn around and look at my part and then I click.

236
00:16:07,520 --> 00:16:12,020
As you can see now we have visualized this raycast with this custom part right here.

237
00:16:12,020 --> 00:16:18,200
This was my origin point and the ray fired in this direction and kept going until it hit my part.

238
00:16:18,200 --> 00:16:21,560
And that's where this part ends, right?

239
00:16:22,190 --> 00:16:27,680
So that is the total distance between the origin point and the point at which we hit.

240
00:16:27,680 --> 00:16:33,350
And of course, we can keep shooting these rays out and keep firing them and keep visualizing them.

241
00:16:33,350 --> 00:16:39,680
And those are all of the ray casts that are being shot out from my origin point, and hitting this part

242
00:16:39,680 --> 00:16:40,340
right here.

243
00:16:40,340 --> 00:16:44,180
And of course, I can't hit anything that is not in front of me.

244
00:16:44,180 --> 00:16:49,130
But if I walk, you can see that the origin point is moving up and down.

245
00:16:49,130 --> 00:16:54,710
And then if I click, as you can see, the look vector of this part is pointed downwards as I walk.

246
00:16:54,710 --> 00:16:56,660
So we're hitting the base plate now.

247
00:16:58,500 --> 00:17:02,790
One more thing before I let you go, let's go ahead and take a look at the Cam query property.

248
00:17:02,790 --> 00:17:03,750
For parts.

249
00:17:03,960 --> 00:17:08,970
To access the can query property, we have to go down to the collision section and the properties panel

250
00:17:08,970 --> 00:17:09,720
for this part.

251
00:17:09,720 --> 00:17:14,760
And in order to see the can query property we have to go ahead and disable can collide.

252
00:17:14,760 --> 00:17:18,450
Once we disable can collide then the can query property shows up.

253
00:17:18,450 --> 00:17:23,670
And this will determine whether or not this part is going to be involved in any spatial queries in the

254
00:17:23,670 --> 00:17:25,590
game, including Raycasts.

255
00:17:25,590 --> 00:17:31,470
So if I disable this property and then we go and playtest our game, now when I go and click my tool

256
00:17:31,470 --> 00:17:35,280
to try and fire a ray at this part, it's not going to intersect anything.

257
00:17:35,280 --> 00:17:37,320
So if I hold out my tool and then I click.

258
00:17:37,320 --> 00:17:41,970
As you can see, this part is now being excluded from that raycast operation.

259
00:17:41,970 --> 00:17:44,580
And it's telling us that the ray hit nothing.

260
00:17:44,580 --> 00:17:49,380
I can keep clicking and keep clicking, and no matter what, the ray is going to permanently ignore

261
00:17:49,380 --> 00:17:50,310
this part.

262
00:17:51,970 --> 00:17:54,760
So this is how we can visualize Raycasts.

263
00:17:54,760 --> 00:18:01,420
And this is also how we can use Raycasts to detect when we hit parts or 3D objects in our game.

264
00:18:02,930 --> 00:18:04,790
That's all for me for this lecture.

265
00:18:04,790 --> 00:18:07,610
I hope you enjoyed and I'll see you in the next one.