IS OBH - Revision history

Flame CZE at 20:25, 26 February 2026

2026-02-26T20:25:54Z

Flame CZE at 11:46, 14 February 2026

2026-02-14T11:46:58Z

Flame CZE at 11:18, 14 February 2026

2026-02-14T11:18:49Z

Bokujishin: Created page with "== Introduction == The '''OB'''ject '''H'''it packet is sent by LFS when a car collides with an object (not only layout objects). This packet is only sent if ISF_OBH is set i..."

2026-02-10T14:55:43Z

Created page with "== Introduction == The '''OB'''ject '''H'''it packet is sent by LFS when a car collides with an object (not only layout objects). This packet is only sent if ISF_OBH is set i..."

New page

== Introduction ==

The '''OB'''ject '''H'''it packet is sent by LFS when a car collides with an object (not only layout objects). This packet is only sent if ISF_OBH is set in [[IS_ISI]].

{| class="wikitable"
|+ IS_OBH packet properties
|-
! Type !! Name !! Description
|-
| byte || Size || 28
|-
| byte || Type || ISP_OBH
|-
| byte || ReqI || 0
|-
| byte || PLID || player's unique id
|-
| word || SpClose || high 4 bits: reserved / low 12 bits: closing speed (10 = 1 m/s)
|-
| word || SpW ||
|-
| unsigned || Time || time stamp (ms)
|-
| CarContOBJ || C ||
|-
| short || X || as in ObjectInfo
|-
| short || Y || as in ObjectInfo
|-
| byte || Zbyte || if OBH_LAYOUT is set: Zbyte as in ObjectInfo
|-
| byte || Sp1 ||
|-
| byte || Index || AXO_x as in ObjectInfo or zero if it is an unknown object
|-
| byte || OBHFlags || see below
|}

== Packet Details ==

=== Size ===

The size of the packet is always 28 bytes.

=== Type ===

The packet type from the [[InSim_enumerations#ISP|ISP_]] enumeration, always ISP_OBH.

=== ReqI ===

ReqI is always equal to zero.

=== SpClose ===

Only the 12 lower bits are used to encode the closing speed, where a value of 10 corresponds to 1 m/s.

=== Time ===

The timestamp of the contact.

=== C ===

A [[InSim_structs#CarContOBJ|CarContOBJ]] giving details about the involved car.

=== X ===

The X coordinate of the object, as in [[InSim_structs#ObjectInfo|ObjectInfo]].

=== Y ===

The Y coordinate of the object, as in [[InSim_structs#ObjectInfo|ObjectInfo]].

=== Zbyte ===

The Z coordinate of the object, as in [[InSim_structs#ObjectInfo|ObjectInfo]].

=== Index ===

The AXO_ index of the object, as in [[InSim_structs#ObjectInfo|ObjectInfo]], or 0 if the object is unknown.

=== OBHFlags ===

Flags for the hit event:
<pre style="tab-size:4">#define OBH_LAYOUT 1 // an added object
#define OBH_CAN_MOVE 2 // a movable object
#define OBH_WAS_MOVING 4 // was moving before this hit
#define OBH_ON_SPOT 8 // object in original position</pre>

== Notes ==

The [[#OBHFlags|OBHFlags]] can help determine if a car hit an object that has already been hit by another car: if OBH_CAN_MOVE and OBH_WAS_MOVING are both set, the car hit a moving object (caused by a previous hit).

[[Category:InSim packets]]

@@ Line 9: / Line 9: @@
 }}
-The '''OB'''ject '''H'''it packet is sent by LFS when a [[:Category:Cars|car]] collides with an object (not only [[List of autocross layout objects|layout objects]]). This packet is only sent if ISF_OBH is set in [[IS_ISI]].
+The '''OB'''ject '''H'''it packet is sent by LFS when a [[Cars|car]] collides with an object (not only [[List of autocross layout objects|layout objects]]). This packet is only sent if ISF_OBH is set in [[IS_ISI]].
 {| class="wikitable"

@@ Line 3: / Line 3: @@
 | size          = 4
 | type_key      = ISP_OBH
-| type_value    = 22
+| type_value    = 51
 | direction     = in
 | prev          = [[IS_CON]]

@@ Line 1: / Line 1: @@
-== Introduction ==
+{{Infobox InSim packet
-The '''OB'''ject '''H'''it packet is sent by LFS when a car collides with an object (not only layout objects). This packet is only sent if ISF_OBH is set in [[IS_ISI]].
+The '''OB'''ject '''H'''it packet is sent by LFS when a [[:Category:Cars|car]] collides with an object (not only [[List of autocross layout objects|layout objects]]). This packet is only sent if ISF_OBH is set in [[IS_ISI]].
 {| class="wikitable"
@@ Line 90: / Line 98: @@
 The [[#OBHFlags|OBHFlags]] can help determine if a car hit an object that has already been hit by another car: if OBH_CAN_MOVE and OBH_WAS_MOVING are both set, the car hit a moving object (caused by a previous hit).
 [[Category:InSim packets]]