I’m working on a 3D game and I was going to settle on it being 3D until I figured out how to make the camera move with the model correctly and also rotate around. The issue I have now is that my players movement doesn’t make sense anymore.
Here is how I was doing it (just for the one key, the others are all the same):
if (kb.IsKeyDown(Keys.Left)){
player_x = player_x + 0.05f;
world_player = Matrix.CreateTranslation(new Vector3(player_x, player_y, player_z));
// use this code for any standard collision
if ((IsCollision(ball, world_player, ball, world_cannon)) || (IsCollision(ball, world_player, ball, walls[0])) || (IsCollision(ball, world_player, ball, walls[1])) || (IsCollision(ball, world_player, ball, walls[2])))
{
player_x = player_x - 0.05f;
world_player = Matrix.CreateTranslation(new Vector3(player_x, player_y, player_z));
}
Where player_x is a static float. Now this is fine for third person, but for 1st person it means even if I am looking along the X axis, I can’t press W because W will take my along the Y axis.
My problem is I want the player to move towards the camera look at, but I am not sure on the math of that? Here is my camera class:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
namespace Game7
{
class Camera : GameComponent
{
private Vector3 cameraPosition;
private Vector3 cameraRotation;
private float cameraSpeed;
private Vector3 cameraLookAt;
private Vector3 mouseRotationBuffer;
private MouseState currentMouseState;
private MouseState previousMouseState;
// Properties
public Vector3 Position
{
get { return cameraPosition; }
set
{
cameraPosition = value;
UpdateLookAt();
}
}
public Vector3 Rotation
{
get { return cameraRotation; }
set
{
cameraRotation = value;
UpdateLookAt();
}
}
public Matrix Projection
{
get;
protected set;
}
public Matrix View
{
get
{
return Matrix.CreateLookAt(cameraPosition, cameraLookAt, Vector3.Up);
}
}
//Constructor
public Camera(Game game, Vector3 position, Vector3 rotation, float speed)
: base(game)
{
cameraSpeed = speed;
// projection matrix
Projection = Matrix.CreatePerspectiveFieldOfView(
MathHelper.PiOver4,
Game.GraphicsDevice.Viewport.AspectRatio,
0.05f,
1000.0f);
// set camera positiona nd rotation
MoveTo(position, rotation);
previousMouseState = Mouse.GetState();
}
// set Camera's position and rotation
private void MoveTo(Vector3 pos, Vector3 rot)
{
Position = pos;
Rotation = rot;
}
//update the look at vector
private void UpdateLookAt()
{
// build rotation matrix
Matrix rotationMatrix = Matrix.CreateRotationX(cameraRotation.X) * Matrix.CreateRotationY(cameraRotation.Y);
// Look at ofset, change of look at
Vector3 lookAtOffset = Vector3.Transform(Vector3.UnitZ, rotationMatrix);
// update our cameras look at vector
cameraLookAt = cameraPosition + lookAtOffset;
}
// Simulated movement
private Vector3 PreviewMove(Vector3 amount)
{
// Create rotate matrix
Matrix rotate = Matrix.CreateRotationY(cameraRotation.Y);
// Create a movement vector
Vector3 movement = new Vector3(amount.X, amount.Y, amount.Z);
movement = Vector3.Transform(movement, rotate);
return cameraPosition + movement;
}
// Actually move the camera
private void Move(Vector3 scale)
{
MoveTo(PreviewMove(scale), Rotation);
}
// updat method
public override void Update(GameTime gameTime)
{
// smooth mouse?
float dt = (float)gameTime.ElapsedGameTime.TotalSeconds;
currentMouseState = Mouse.GetState();
KeyboardState ks = Keyboard.GetState();
// input
Vector3 moveVector = Vector3.Zero;
if (ks.IsKeyDown(Keys.W))
moveVector.Z = 1;
if (ks.IsKeyDown(Keys.S))
moveVector.Z = -1;
if (ks.IsKeyDown(Keys.A))
moveVector.X = 1;
if (ks.IsKeyDown(Keys.D))
moveVector.X = -1;
if (moveVector != Vector3.Zero)
{
//normalize it
//so that we dont move faster diagonally
moveVector.Normalize();
// now smooth and speed
moveVector *= dt * cameraSpeed;
// move camera
Move(moveVector);
}
// Handle mouse input
float deltaX;
float deltaY;
if(currentMouseState != previousMouseState)
{
//Cache mouse location
deltaX = currentMouseState.X - (Game.GraphicsDevice.Viewport.Width / 2);
deltaY = currentMouseState.Y - (Game.GraphicsDevice.Viewport.Height / 2);
// smooth mouse ? rotation
mouseRotationBuffer.X -= 0.01f * deltaX * dt;
mouseRotationBuffer.Y -= 0.01f * deltaY * dt;
if (mouseRotationBuffer.Y < MathHelper.ToRadians(-75.0f))
mouseRotationBuffer.Y = mouseRotationBuffer.Y - (mouseRotationBuffer.Y - MathHelper.ToRadians(-75.0f));
if (mouseRotationBuffer.Y > MathHelper.ToRadians(75.0f))
mouseRotationBuffer.Y = mouseRotationBuffer.Y - (mouseRotationBuffer.Y - MathHelper.ToRadians(75.0f));
Rotation = new Vector3(-MathHelper.Clamp(mouseRotationBuffer.Y, MathHelper.ToRadians(-75.0f), MathHelper.ToRadians(75.0f)), MathHelper.WrapAngle(mouseRotationBuffer.X), 0);
deltaX = 0;
deltaY = 0;
}
// Alt + F4 to close now.
// Makes sure the mouse doesn't wander across the screen (might be a little buggy by showing the mouse)
Mouse.SetPosition(Game.GraphicsDevice.Viewport.Width / 2, Game.GraphicsDevice.Viewport.Height / 2);
previousMouseState = currentMouseState;
base.Update(gameTime);
}
}
}
As always, any help would greatly be appreciated.
Oh and this is how the camera is called in Game1:
camera = new Camera(this, new Vector3(10f, 6f, 5f), Vector3.Zero, 5f);
Components.Add(camera);
And then updated to follow player:
camera.Position = new Vector3(player_x, player_y, player_z);