Problem shooting people in 3rd person view
by Terence Tan · in Torque Game Engine · 06/23/2006 (6:23 am) · 2 replies
Hi,
I am trying to shoot these korks in 3rd person view:
www.posdreams.com/TORQ.jpg
My first try was to use Dave Myers Object selection resource to some success. I was able to select 'objects' and alternate my projectiles vector to hit them.
So I thought about raycasting from the players eye position straight out. I set pitch to zero (yaw is controlled by my mouse cursor).
It doesn't work (or works intermittently)..
So now I'm stumped, have a bad cold and a headache. I do have access to the screen coordinates (and unprojected world coordinates)..so my best next guess is to figure out how to ray cast from the player position(and or box center) to a tranformed world coordinate??? By the camera perhaps?
Apologize if i mispell anything or typed something about dancing pink elephants...cough cough
I am trying to shoot these korks in 3rd person view:
www.posdreams.com/TORQ.jpg
My first try was to use Dave Myers Object selection resource to some success. I was able to select 'objects' and alternate my projectiles vector to hit them.
So I thought about raycasting from the players eye position straight out. I set pitch to zero (yaw is controlled by my mouse cursor).
%player = %client.player;
//Determine how far should the picking ray extend into the world?
%selectRange = 400;
%forwardVec = %player.getEyeVector();
%forwardScaled = VectorScale(%forwardVec, %selectRange);
// Search for anything that is selectable – below are some examples
%searchMasks = $TypeMasks::PlayerObjectType | $TypeMasks::CorpseObjectType |
$TypeMasks::ItemObjectType | $TypeMasks::TriggerObjectType;
// %scanTarg = ContainerRayCast (%cameraPoint, %rangeEnd, %searchMasks);
echo("Trying to target somebody");
// %pos = getBoxCenter(%player.getWorldBox());
%scanTarg = ContainerRayCast (%player.getPosition(), %forwardScaled, %searchMasks,%player);It doesn't work (or works intermittently)..
So now I'm stumped, have a bad cold and a headache. I do have access to the screen coordinates (and unprojected world coordinates)..so my best next guess is to figure out how to ray cast from the player position(and or box center) to a tranformed world coordinate??? By the camera perhaps?
Apologize if i mispell anything or typed something about dancing pink elephants...cough cough
About the author
#2
- In the initial ray trace, if the object hit is a terrain then use the X,Y,Z location as the target
- If the object is a character then set it as the target
It seems to work well enough for now, until I get more significant gameplay working. For some reason using the elevated normal from the terrain didn't seem to work well. The problem I had was also that the height units are in meters so a 6m character stupid
06/28/2006 (8:22 pm)
After a little of testing I finally settled on:- In the initial ray trace, if the object hit is a terrain then use the X,Y,Z location as the target
- If the object is a character then set it as the target
It seems to work well enough for now, until I get more significant gameplay working. For some reason using the elevated normal from the terrain didn't seem to work well. The problem I had was also that the height units are in meters so a 6m character stupid
//Determine how far should the picking ray extend into the world?
%selectRange = 400;
// scale mouseVec to the range the player is able to select with mouse
%mouseScaled = VectorScale(%mouseVec, %selectRange);
// cameraPoint = the world position of the camera
// rangeEnd = camera point + length of selectable range
%rangeEnd = VectorAdd(%cameraPoint, %mouseScaled);
// Search for anything that is selectable – below are some examples
// %searchMasks = $TypeMasks::PlayerObjectType | $TypeMasks::CorpseObjectType |
// $TypeMasks::ItemObjectType | $TypeMasks::TriggerObjectType;
%searchMasks = $TypeMasks::TerrainObjectType | $TypeMasks::PlayerObjectType;
// Search for objects within the range that fit the masks above. If we are
// in first person mode, we make sure player is not selectable by setting
// fourth parameter (exempt from collisions) when calling ContainerRayCast
%player = %client.player;
%target = ContainerRayCast (%cameraPoint, %rangeEnd, %searchMasks,%player);
if (%target)
{
%obj = getWord(%target,0);
echo ("Object get type returns ",%obj.getType());
if (%obj.getType() & $TypeMasks::TerrainObjectType)
{
%xx = getWord(%target, 1);
%yy = getWord(%target, 2);
%zz = getWord(%target, 3);
%nx = getWord(%target, 4);
%ny = getWord(%target, 5);
%nz = getWord(%target, 6);
%height = 0.5; // Height of average character
%finalPos = %xx SPC %yy SPC %zz;
%player.setTargetPosition(%finalPos);
}
else
{
%player.setTarget(%obj);
}
$mvTriggerCount0++;
} 
Torque Owner Terence Tan
1) Ray cast from the camerpos to the clickpos using the mousevec until it hits a terrain
2) Offset the terrain position by 5 units to cater for height
3) ray cast again from player eye position to the new terrain position to see what I hit.
Doing 2 ray casts seems a bit excessive but I am unsure how else to approach this. It still doesn't work either.
See code:
//Determine how far should the picking ray extend into the world? %selectRange = 400; // scale mouseVec to the range the player is able to select with mouse %mouseScaled = VectorScale(%mouseVec, %selectRange); // cameraPoint = the world position of the camera // rangeEnd = camera point + length of selectable range %rangeEnd = VectorAdd(%cameraPoint, %mouseScaled); // Search for anything that is selectable – below are some examples // %searchMasks = $TypeMasks::PlayerObjectType | $TypeMasks::CorpseObjectType | // $TypeMasks::ItemObjectType | $TypeMasks::TriggerObjectType; %searchMasks = $TypeMasks::TerrainObjectType; // Search for objects within the range that fit the masks above. If we are // in first person mode, we make sure player is not selectable by setting // fourth parameter (exempt from collisions) when calling ContainerRayCast %player = %client.player; %target = ContainerRayCast (%cameraPoint, %rangeEnd, %searchMasks); if (%target) { %xx = getWord(%target, 1); %yy = getWord(%target, 2); %zz = getWord(%target, 3); %nx = getWord(%target, 4); %ny = getWord(%target, 5); %nz = getWord(%target, 6); %height = 6; // Height of average character %normal = %nx SPC %ny SPC %nz; %finalPos = %xx SPC %yy SPC %zz; %finalPos = VectorAdd(%finalPos,VectorScale(%normal,%height)); echo ("Terrain found ",%finalPos); %playerEye = %player.getEyePoint(); %viewVec = VectorSub(%finalPos,%playerEye); %viewVec = VectorNormalize(%viewVec); %endPoint = VectorAdd(%playerEye, VectorScale(%viewVec, 50)); %searchMasks = $TypeMasks::PlayerObjectType; %scanTarget = ContainerRayCast (%playerEye,%endPoint, %searchMasks,%player); echo ("Scan for target from ",%playerEye, " to " , %endPoint); if (%scanTarget) { echo("Player found at location"); %targetObject = firstWord(%scanTarget); %client.setSelectedObject(%targetObject); } }I'm missing something stupid aren't I?