Game Development Reference
In-Depth Information
Shooting blocks
Now that we have some basic lighting, a physics plane, and the ability to create and simu-
late physics objects, it's time to start shooting things. Before we jump head-first into creat-
ing agents, we'll take a quick detour into accessing some of the physics aspects of sandbox
objects, as well as interacting with input controls.
The
Sandbox_HandleEvent
function allows the sandbox to respond to mouse and
keyboard inputs. The event parameter is a Lua table that stores the source of the event,
whether the event was generated by a down or up key press, and what key caused the
event. Mouse-movement events are similar, but contain the width and height location of the
mouse cursor.
As we already know how to create a sandbox object, all we need to do to shoot objects is
position the object at the camera's position and orientation and apply a physics impulse on
the object.
In this case, we're going to create and shoot a block on a
space_key
press event. The
camera's position and forward vector can be returned from the sandbox using the
Sand-
box.GetCameraPosition
and
Sandox.GetCameraForward
functions. We'll as-
sign the position and orientation to the block and apply a force to the block in the camera's
forward direction. To add a bit of spin to the object, you can use the
Core.ApplyAngularImpulse
function to cause the block to start spinning as it flies
through the air:
Sandbox.lua
:
function Sandbox_HandleEvent(sandbox, event)
if (event.source == "keyboard" and
event.pressed and event.key == "space_key" ) then
local block = Sandbox.CreateObject(
sandbox,
"models/nobiax_modular/modular_block.mesh");
local cameraPosition =
Sandbox.GetCameraPosition(sandbox);
-- Normalized forward camera vector.
