Moving a camera in XNA, C# - c#

I am trying to make a scrolling level to a test game I am doing as a learning exercise. I have created a map containing lots of tiles which are drawn according to their position in an array. I basically want the camera to scroll down the level, but at the moment it just frantically shakes up and down a little bit.
I have a camera class which is just a blank static class containing a static vector2 for the camera location. It is just set as 50, 50 as all the tiles are 50 by 50.
Then in my maps update method I have the following:
public void Update(GameTime gameTime) {
Camera.Location.Y = MathHelper.Clamp(Camera.Location.Y + (float)speed, 0, (300 - 18) * 50)
}
The 300 and 18 are the total number of tiles and the number of tiles on screen (vertically).
I am completely lost so would appreciate any help or advice.

Here's a simple 2D camera class that I use in my games.
public class Camera2D
{
public Camera2D()
{
Zoom = 1;
Position = Vector2.Zero;
Rotation = 0;
Origin = Vector2.Zero;
Position = Vector2.Zero;
}
public float Zoom { get; set; }
public Vector2 Position { get; set; }
public float Rotation { get; set; }
public Vector2 Origin { get; set; }
public void Move(Vector2 direction)
{
Position += direction;
}
public Matrix GetTransform()
{
var translationMatrix = Matrix.CreateTranslation(new Vector3(Position.X, Position.Y, 0));
var rotationMatrix = Matrix.CreateRotationZ(Rotation);
var scaleMatrix = Matrix.CreateScale(new Vector3(Zoom, Zoom, 1));
var originMatrix = Matrix.CreateTranslation(new Vector3(Origin.X, Origin.Y, 0));
return translationMatrix * rotationMatrix * scaleMatrix * originMatrix;
}
}
The idea is to apply it as a transform when you are about you draw your sprite batch like so:
var screenScale = GetScreenScale();
var viewMatrix = Camera.GetTransform();
_spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.NonPremultiplied,
null, null, null, null, viewMatrix * Matrix.CreateScale(screenScale));
You probably also noticed the use of a screen scale. Although not directly related to the camera, it's a way to make sure your screen is scaled to the desired resolution. This way you can draw your scene independent of resolution and scale it at the end. Here's the screen scale method for reference:
public Vector3 GetScreenScale()
{
var scaleX = (float)_graphicsDevice.Viewport.Width / (float)_width;
var scaleY = (float)_graphicsDevice.Viewport.Height / (float)_height;
return new Vector3(scaleX, scaleY, 1.0f);
}

Related

Sprites Auto Position and scale

I have 4 sprites with colliders, I want to auto position and scale them to the bottom of the screen evenly so they don't over lap and they are not off screen at all. I can not do this in canvas it needs to be done as gameObjects.
I also am trying to get each Sprits height to be 1/4th-1/5th depending on how it looks, that's why the code is divided by 4 down below.
How do I get them to position on the bottome and side by side?
public class AutoPosition : MonoBehaviour {
public Sprite [] goals;
public float width = Screen.width / 4;
public float height = Screen.height / 4;
// Use this for initialization
void Start () {
for (int i = 0; i < goals.Length; i++) {
goals[i]
}
}
You can use SpriteRender for the images. And position them inside of a parent GameObject. Than it is enough to simply scale and position that one Parent GameObject correctly (similar to the canvas but with normal Transform components).
public class applySize : MonoBehaviour
{
private void Apply()
{
// Get the main camera position
var cameraPosition = Camera.main.transform.position;
// This makes the parent GameObject "fit the screen size"
float height;
if (Camera.main.orthographic)
{
// Camera projection is orthographic
height = 2 * Camera.main.orthographicSize;
}
else
{
// Camera projection is perspective
height = 2 * Mathf.Tan(0.5f * Camera.main.fieldOfView * Mathf.Deg2Rad) * Mathf.Abs(cameraPosition.z - transform.position.z);
}
var width = height * Camera.main.aspect;
transform.localScale = new Vector3(width, height,1);
transform.position = cameraPosition - new Vector3(0,height*.375f, cameraPosition.z);
// Since the 4 images are childs of the parent GameObject there is no need
// place or scale them separate. It is all done with placing this parent object
}
private void Start()
{
Apply();
}
}
Using the following Scene setup
The X positions of the Sprites simply are
image1: - width * 1.5;
image2: - width * 0.5;
image3: width * 0.5;
image4: width * 1.5;
and for the four SpriteRenderers
and the colliders
Result
(with an additional call in Update)
I made the Parent position stay on Z = 0. You can change this according to your needs.
This way the colliders should now be able to interact with other objects.

Monogame - Making the camera stop when my player collides

I have come to a position with my 3D game where I am now trying to perfect the camera. What I ultimately want is a working first person camera that stops when it collides with a wall. I assume you do this by having the camera move with a model and have the model collide to stop the camera also, i am just having issues seeing how to do that.
I have the model working so it stops, i just need to lock the camera from moving also. So far this is the code I have, making the model stop with collison:
if (player_health != 0)
{
if (kb.IsKeyDown(Keys.Left))
{
player_x = player_x + 0.05f;
world_player = Matrix.CreateTranslation(new Vector3(player_x, player_y, player_z));
if (IsCollision(ball, world_player, ball, world_spike))
{
player_x = player_x - 0.05f;
world_player = Matrix.CreateTranslation(new Vector3(player_x, player_y, player_z));
player_health = 0;
}
if (IsCollision(ball, world_player, ball, world_bullet[0]))
{
player_health = 0;
}
// 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])))
{
player_x = player_x - 0.05f;
world_player = Matrix.CreateTranslation(new Vector3(player_x, player_y, player_z));
}
}
My camera added into the game1 class:
camera = new Camera(this, new Vector3(10f, 3f, 5f), Vector3.Zero, 5f);
Components.Add(camera);
And the camera class itself (I have been told this is rather over complicated? for a camera class, but the simpler ones didnt work):
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);
}
}
}
The Preview Move part of the camera class is meant to be where it detects for collision, at least the guide i followed said so, i just dont see how to integrate it. Thanks for any help or input, even if it is just a link to another guide or resource, would be very appreciated!
If your hero model (player) already has move functionality and collision functionality, and you want the camera to follow the model, then you can simplify the camera update tremendously.
Assuming after moving the player, the new position and/or orientation of the player is represented in player_world, simply borrow the location and orientation information stored in the player_world matrix to build a view matrix each frame.
//after moving player and setting its matrix accordingly:
view = Matrix.Invert(player_world);
And that is your complete camera class update. This creates a view matrix that is in the same position as the player and facing the same direction he is. If the player model stops because it hits a wall, then the camera (view matrix) stops too, because it is built from the player's 'stopped' matrix. No need to create a whole class for moving and rotating the camera around when the movement and rotation is the same as the player.
Sometimes the local player model origin would be located at the player's feet or belly and you want the camera up in the head where the eyes are. If so, simply apply something like this:
//after moving player and setting its matrix accordingly:
Matrix camera_world = player_world;
camera_world *= Matrix.CreateTranslation(Vector3.Up * ??f);// set ??f to the height difference between feet and head
view = Matrix.Invert(camera_world);

How to draw a sprite on a moving canvas

I generally figure this sort of thing out normally but I am stumped. I suspect theres a mathematical combination I have missed but anyway.
I have a moving background (currently goes up and down from top to bottom)
I have a moving object (currently moves left and right from the centre of the canvas programatically).
So this is the question, How can I make an object move relatively to the position on the canvas in x and y directions?
Here is my relevant codes:
//Helper method
private Vector2 CalculateDirection()
{
Vector2 calculatedDirection = new Vector2((float)Math.Cos(direction),
(float)Math.Sin(direction));
calculatedDirection.Normalize();
return calculatedDirection;
}
object on canvas
public void Update(GameTime gameTime, Vector2 center)
{
this.currentCentre = originalCentre - center;
//movement logic here
Vector2 calculatedDirection = CalculateDirection();
//deltaTime = ((float)gameTime.ElapsedGameTime.TotalMilliseconds) / 15f;
if (speed > 0f || speed < 0f)
{
///TODO: work this out!!
Velocity = calculatedDirection * speed;
float dir = (originalCentre.Y - currentCentre.Y);
position.X += Velocity.X * (1.0f - 0.9f);
position.Y = dir;// *(1.0f - 0.9f);
}
}
canvas moving methods
private void determinePitchSize()
{
int newHeight = Convert.ToInt32(pitch.Height * ratio);
this.canvas = new Rectangle(
0, posHeight,
device.PresentationParameters.BackBufferWidth,
newHeight
);
}
public void increasePosHeight()
{
posHeight++;
}
public void decreasePosHeight()
{
posHeight--;
}
private void determineDirection()
{
if (!direction)
{
if (this.canvas.Height + this.canvas.Y <= this.screenY)
direction = true;
}
else
{
if (this.canvas.Y >= 0)
direction = false;
}
}
private void useDirection()
{
this.determineDirection();
if (direction)
this.increasePosHeight();
else decreasePosHeight();
}
If you need any more info I can add it here.
Thanks
Ok so thanks to Nico, I was able to answer this.
Vector2 Velocity { get; set; }
Vector2 relative { get; set; }
public void Update(GameTime gameTime, Vector2 center)
{
this.currentCentre = center;
Vector2 calculatedDirection = CalculateDirection();
if (speed > 0f || speed < 0f)
{
Velocity = calculatedDirection * speed * 0.1f;
relative = relative - Velocity;
position = currentCentre + relative;
}
}
The velocity creates object movement to test that it ends up in a different place.
Relative starts at 0,0 (the center) and is adjusted by the velocity.
Position is then set to the centre plus the relative position. which has been set by the velocity.

Meshes starting to jump on camera rotation/movement

Hey together,
first time posting here, because I'm damn stuck...
The further away a mesh is from the origin at (0, 0, 0), the more it "jumps"/"flickers" when rotating or moving the camera. It's somehow hard to describe this effect: it is like the mesh is jittering/shivering/trembling a little bit and this trembling gets bigger and bigger as you gain distance to the origin.
For me, it begins to be observable at around 100000 units distance to the origin, so at (0, 0, 100000) for example. Neither the axis of the translation nor the type of the mesh (default mesh created from Mesh.Create... or with assimp.NET imported 3ds mesh) have influence on this effect. The value of the position of the mesh doesn't change when this effect occurs, checked this by logging the position.
If I'm not missing something, this narrows it down to two possibilities:
My camera code
The DirectX-Device
As for the DirectX-Device, this is my device initialization code:
private void InitializeDevice()
{
//Initialize D3D
_d3dObj = new D3D9.Direct3D();
//Set presentation parameters
_presParams = new D3D9.PresentParameters();
_presParams.Windowed = true;
_presParams.SwapEffect = D3D9.SwapEffect.Discard;
_presParams.AutoDepthStencilFormat = D3D9.Format.D16;
_presParams.EnableAutoDepthStencil = true;
_presParams.PresentationInterval = D3D9.PresentInterval.One;
_presParams.BackBufferFormat = _d3dObj.Adapters.DefaultAdapter.CurrentDisplayMode.Format;
_presParams.BackBufferHeight = _d3dObj.Adapters.DefaultAdapter.CurrentDisplayMode.Height;
_presParams.BackBufferWidth = _d3dObj.Adapters.DefaultAdapter.CurrentDisplayMode.Width;
//Set form width and height to current backbuffer width und height
this.Width = _presParams.BackBufferWidth;
this.Height = _presParams.BackBufferHeight;
//Checking device capabilities
D3D9.Capabilities caps = _d3dObj.GetDeviceCaps(0, D3D9.DeviceType.Hardware);
D3D9.CreateFlags devFlags = D3D9.CreateFlags.SoftwareVertexProcessing;
D3D9.DeviceType devType = D3D9.DeviceType.Reference;
//setting device flags according to device capabilities
if ((caps.VertexShaderVersion >= new Version(2, 0)) && (caps.PixelShaderVersion >= new Version(2, 0)))
{
//if device supports vertexshader and pixelshader >= 2.0
//then use the hardware device
devType = D3D9.DeviceType.Hardware;
if (caps.DeviceCaps.HasFlag(D3D9.DeviceCaps.HWTransformAndLight))
{
devFlags = D3D9.CreateFlags.HardwareVertexProcessing;
}
if (caps.DeviceCaps.HasFlag(D3D9.DeviceCaps.PureDevice))
{
devFlags |= D3D9.CreateFlags.PureDevice;
}
}
//initialize the device
_device = new D3D9.Device(_d3dObj, 0, devType, this.Handle, devFlags, _presParams);
//set culling
_device.SetRenderState(D3D9.RenderState.CullMode, D3D9.Cull.Counterclockwise);
//set texturewrapping (needed for seamless spheremapping)
_device.SetRenderState(D3D9.RenderState.Wrap0, D3D9.TextureWrapping.All);
//set lighting
_device.SetRenderState(D3D9.RenderState.Lighting, false);
//enabling the z-buffer
_device.SetRenderState(D3D9.RenderState.ZEnable, D3D9.ZBufferType.UseZBuffer);
//and setting write-access exlicitly to true...
//i'm a little paranoid about this since i had to struggle for a few days with weirdly overlapping meshes
_device.SetRenderState(D3D9.RenderState.ZWriteEnable, true);
}
Am I missing a flag or renderstate? Is there something that could cause such a weird/distorted behaviour?
My camera class is based on Michael Silvermans C++ Quaternion Camera:
//every variable prefixed with an underscore is
//a private static variable initialized beforehand
public static class Camera
{
//gets called every frame
public static void Update()
{
if (_filter)
{
_filteredPos = Vector3.Lerp(_filteredPos, _pos, _filterAlpha);
_filteredRot = Quaternion.Slerp(_filteredRot, _rot, _filterAlpha);
}
_device.SetTransform(D3D9.TransformState.Projection, Matrix.PerspectiveFovLH(_fov, _screenAspect, _nearClippingPlane, _farClippingPlane));
_device.SetTransform(D3D9.TransformState.View, GetViewMatrix());
}
public static void Move(Vector3 delta)
{
_pos += delta;
}
public static void RotationYaw(float theta)
{
_rot = Quaternion.Multiply(Quaternion.RotationAxis(_up, -theta), _rot);
}
public static void RotationPitch(float theta)
{
_rot = Quaternion.Multiply(_rot, Quaternion.RotationAxis(_right, theta));
}
public static void SetTarget(Vector3 target, Vector3 up)
{
SetPositionAndTarget(_pos, target, up);
}
public static void SetPositionAndTarget(Vector3 position, Vector3 target, Vector3 upVec)
{
_pos = position;
Vector3 up, right, lookAt = target - _pos;
lookAt = Vector3.Normalize(lookAt);
right = Vector3.Cross(upVec, lookAt);
right = Vector3.Normalize(right);
up = Vector3.Cross(lookAt, right);
up = Vector3.Normalize(up);
SetAxis(lookAt, up, right);
}
public static void SetAxis(Vector3 lookAt, Vector3 up, Vector3 right)
{
Matrix rot = Matrix.Identity;
rot.M11 = right.X;
rot.M12 = up.X;
rot.M13 = lookAt.X;
rot.M21 = right.Y;
rot.M22 = up.Y;
rot.M23 = lookAt.Y;
rot.M31 = right.Z;
rot.M32 = up.Z;
rot.M33 = lookAt.Z;
_rot = Quaternion.RotationMatrix(rot);
}
public static void ViewScene(BoundingSphere sphere)
{
SetPositionAndTarget(sphere.Center - new Vector3((sphere.Radius + 150) / (float)Math.Sin(_fov / 2), 0, 0), sphere.Center, new Vector3(0, 1, 0));
}
public static Vector3 GetLookAt()
{
Matrix rot = Matrix.RotationQuaternion(_rot);
return new Vector3(rot.M13, rot.M23, rot.M33);
}
public static Vector3 GetRight()
{
Matrix rot = Matrix.RotationQuaternion(_rot);
return new Vector3(rot.M11, rot.M21, rot.M31);
}
public static Vector3 GetUp()
{
Matrix rot = Matrix.RotationQuaternion(_rot);
return new Vector3(rot.M12, rot.M22, rot.M32);
}
public static Matrix GetViewMatrix()
{
Matrix viewMatrix, translation = Matrix.Identity;
Vector3 position;
Quaternion rotation;
if (_filter)
{
position = _filteredPos;
rotation = _filteredRot;
}
else
{
position = _pos;
rotation = _rot;
}
translation = Matrix.Translation(-position.X, -position.Y, -position.Z);
viewMatrix = Matrix.Multiply(translation, Matrix.RotationQuaternion(rotation));
return viewMatrix;
}
}
Do you spot anything in the camera code which could cause this behaviour?
I just can't imagine that DirectX can't handle distances greater than 100k. I am supposed to render solar systems and I'm using 1 unit = 1km. So the earth would be rendered at its maximum distance to the sun at (0, 0, 152100000) (just as an example). This is becoming impossible if these "jumps" keep occuring.
Finally i thought about scaling everything down, so that a system never goes beyond 100k/-100k distance from the origin, but I think this won't work because the "jittering" gets bigger as the distance from the origin gets bigger. Scaling everything down would - i think - scale down the jumping-behaviour, too.
Just to not leave this question unanswered (credits to #jcoder, see comments of question):
The weird behaviour of the meshes comes from the floating point precision of DX. The bigger your world gets, the less precision is there to calculate positions accurately.
There are two possibilities to solve this problem:
Downscaling the whole world
this may be problematic in a "galactic-style" world, where you have really big position offsets as well as really small ones (i.e. the distance of a planet to its sun is really big, but the distance of a spaceship in orbit of a planet may be really small)
Dividing the world into smaller chunks
this way you have either to express all positions relative to something else (see stackoverflow.com/questions/1930421) or make multiple worlds and somehow move between them

Ground and model are flickering and somewhat invisable

I really don't know whats is going wrong here. The game seams to be drawing funny. The first thing I notice is that when the player moves, the camera move before the avatar does so the camera comes out of the avatars head a bit. Then I noticed that when you look at the avatar from the side you can see though his shoulder and into his cheast cavity (it does not do this in the animation player I build and also in Maya). The next thing I notice is when the player moves forward, the ground starts to flicker. Am I calling the draw method wrong or something?
here is the camera class I am using
public class Camera : Microsoft.Xna.Framework.GameComponent
{
//Cam Matrices
//viw is composed of position, direction, and up vectors
public Matrix view { get; protected set; }
public Matrix projection { get; protected set; }
//to move the camera
//used to recreate view matrix each frame
public Vector3 cameraPosition { get; protected set; }
public Vector3 cameraDirection; //not the target/ point camera is looking at a relative direction camrea is faceing
//to find target add the cameraPosition and cameraDirection togeater
public Vector3 cameraUp;
public Vector3 target;
//camera controls
float speed = 3;
MouseState prevMouseState;
// Pi/180 = 1 degree
// Max yaw/pitch variables
//this is for moving the head only not the body
float totalYaw = MathHelper.PiOver2;
public float currentYaw = 0;
float totalPitch = MathHelper.PiOver2;
public float currentPitch = 0;
public float leftTrigYaw;
public float rightTrigYaw;
//constructor
public Camera(Game game, Vector3 pos, Vector3 target, Vector3 up)
: base(game)
{
//build camera view matrix
cameraPosition = pos;
cameraDirection = target - pos;
cameraDirection.Normalize(); //Convert to magintue 1
//make it easy to apply differt speeds to movement of camera
cameraUp = up;
CreateLookAt();
projection = Matrix.CreatePerspectiveFieldOfView
(
MathHelper.PiOver4,
(float)Game.Window.ClientBounds.Width / (float)Game.Window.ClientBounds.Height,
1, 3000);
}
private void CreateLookAt()
{
//middle variable is the target!
view = Matrix.CreateLookAt(cameraPosition, cameraPosition + cameraDirection, cameraUp);
}
public override void Initialize()
{
Mouse.SetPosition(Game.Window.ClientBounds.Width / 2,
Game.Window.ClientBounds.Height / 2);
prevMouseState = Mouse.GetState();
base.Initialize();
}
public override void Update(GameTime gameTime)
{
GamePadState currentState = GamePad.GetState(PlayerIndex.One);
//move forward
if (currentState.ThumbSticks.Left.Y > 0 || Keyboard.GetState().IsKeyDown(Keys.W))
{
//move just on x and x axis Y is controled other places.
cameraPosition += new Vector3(cameraDirection.X, 0, cameraDirection.Z) * speed;
}
//move backward
if (currentState.ThumbSticks.Left.Y < 0 || Keyboard.GetState().IsKeyDown(Keys.S))
{
//move just on x and x axis Y is controled other places.
cameraPosition -= new Vector3(cameraDirection.X, 0, cameraDirection.Z) * speed;
}
//move left
if (currentState.ThumbSticks.Left.X < 0 || Keyboard.GetState().IsKeyDown(Keys.A))
{
//cross product of the up and direction vectors can give the side direction
cameraPosition += Vector3.Cross(cameraUp, cameraDirection) * speed;
}
//move right
if (currentState.ThumbSticks.Left.X > 0 || Keyboard.GetState().IsKeyDown(Keys.D))
{
cameraPosition -= Vector3.Cross(cameraUp, cameraDirection) * speed;
}
//mouse movements
// Yaw rotation
float yawAngle = (-MathHelper.PiOver4 / 150) *
(Mouse.GetState().X - prevMouseState.X);
float padYaw = (-MathHelper.PiOver2 / 50) *
(currentState.ThumbSticks.Right.X);
if (Math.Abs(currentYaw + yawAngle) < totalYaw)
{
cameraDirection = Vector3.Transform(cameraDirection,
Matrix.CreateFromAxisAngle(cameraUp, yawAngle));
currentYaw += yawAngle;
}
//rotate left and right
if (currentState.ThumbSticks.Right.X < 0 || currentState.ThumbSticks.Right.X > 0)
{
if (Math.Abs(currentYaw + padYaw) < totalYaw)
{
cameraDirection = Vector3.Transform(cameraDirection,
Matrix.CreateFromAxisAngle(cameraUp, padYaw));
currentYaw += padYaw;
}
}
leftTrigYaw = (MathHelper.PiOver2 / 50) *
(currentState.Triggers.Left);
if (currentState.Triggers.Left > 0.0f)
{
cameraDirection = Vector3.Transform(cameraDirection,
Matrix.CreateFromAxisAngle(cameraUp, leftTrigYaw));
}
rightTrigYaw = (-MathHelper.PiOver2 / 50) *
(currentState.Triggers.Right);
if (currentState.Triggers.Right > 0.0f)
{
cameraDirection = Vector3.Transform(cameraDirection,
Matrix.CreateFromAxisAngle(cameraUp, rightTrigYaw));
}
// Pitch rotation
float pitchAngle = (MathHelper.PiOver4 / 150) *
(Mouse.GetState().Y - prevMouseState.Y);
float padPitch = (-MathHelper.PiOver2 / 50) *
(currentState.ThumbSticks.Right.Y);
if (Math.Abs(currentPitch + pitchAngle) < totalPitch)
{
cameraDirection = Vector3.Transform(cameraDirection,
Matrix.CreateFromAxisAngle(
Vector3.Cross(cameraUp, cameraDirection),
pitchAngle));
currentPitch += pitchAngle;
}
if (currentState.ThumbSticks.Right.Y < 0 || currentState.ThumbSticks.Right.Y > 0)
{
if (Math.Abs(currentPitch + padPitch) < totalPitch)
{
cameraDirection = Vector3.Transform(cameraDirection,
Matrix.CreateFromAxisAngle(
Vector3.Cross(cameraUp, cameraDirection),
padPitch));
currentPitch += padPitch;
}
}
//reset mouse state
target = cameraPosition + cameraDirection;
prevMouseState = Mouse.GetState();
//for testing only!! get rid of this when done
if (currentState.Buttons.A == ButtonState.Pressed)
{
//fly upwar
cameraPosition += new Vector3(0, 15, 0);
}
if (currentState.Buttons.B == ButtonState.Pressed)
{
//fly upwar
cameraPosition -= new Vector3(0, 15, 0);
}
//call camera creat look at method to build new view matrix
CreateLookAt();
if (Keyboard.GetState().IsKeyDown(Keys.Escape))
{
Game.Exit();
}
base.Update(gameTime);
}
}
}
I am also using a custom model handler to draw the ground and the avatar
public class CModel
{
public Vector3 Position { get; set; }
public Vector3 Rotation { get; set; }
public Vector3 Scale { get; set; }
public Model Model { get; private set; }
private Matrix[] modelTransforms;
private GraphicsDevice graphicsDevice;
public CModel(Model Model, Vector3 Position, Vector3 Rotation,
Vector3 Scale, GraphicsDevice graphicsDevice)
{
this.Model = Model;
modelTransforms = new Matrix[Model.Bones.Count];
Model.CopyAbsoluteBoneTransformsTo(modelTransforms);
this.Position = Position;
this.Rotation = Rotation;
this.Scale = Scale;
this.graphicsDevice = graphicsDevice;
}
public void Draw(Matrix View, Matrix Projection)
{
// Calculate the base transformation by combining
// translation, rotation, and scaling
Matrix baseWorld = Matrix.CreateScale(Scale)
* Matrix.CreateFromYawPitchRoll(
Rotation.Y, Rotation.X, Rotation.Z)
* Matrix.CreateTranslation(Position);
foreach (ModelMesh mesh in Model.Meshes)
{
Matrix localWorld = modelTransforms[mesh.ParentBone.Index]
* baseWorld;
foreach (ModelMeshPart meshPart in mesh.MeshParts)
{
BasicEffect effect = (BasicEffect)meshPart.Effect;
effect.World = localWorld;
effect.View = View;
effect.Projection = Projection;
effect.EnableDefaultLighting();
}
mesh.Draw();
}
}
}
}
I dont know where the problem is originating from but these are the only two things that I can think of that would give the problem.
Thanks for any help with this.
Here is what is going on with the model. I am sure that the normal are right in maya because I used the simple model drawer that Microsoft has up on the tutorials but then you can somewhat see though the guys shoulder and arm. I could not get a picture of the ground flickering because it happens too fast to really screen capture it.But every time i move the camera, the ground jumps up and down a lot. and then stops when I stop moving the camera to look around. am I not calling the the camera.Update() method because its a game component and is linked up with the game1 class.
This is how I am drawing the models
it is a draw method in the custom model class
public void Draw(Matrix View, Matrix Projection)
{
// Calculate the base transformation by combining
// translation, rotation, and scaling
Matrix baseWorld = Matrix.CreateScale(Scale)
* Matrix.CreateFromYawPitchRoll(
Rotation.Y, Rotation.X, Rotation.Z)
* Matrix.CreateTranslation(Position);
foreach (ModelMesh mesh in Model.Meshes)
{
Matrix localWorld = modelTransforms[mesh.ParentBone.Index]
* baseWorld;
foreach (ModelMeshPart meshPart in mesh.MeshParts)
{
BasicEffect effect = (BasicEffect)meshPart.Effect;
effect.World = localWorld;
effect.View = View;
effect.Projection = Projection;
effect.EnableDefaultLighting();
}
mesh.Draw();
}
}
For the artifacts on the model: The model doesn't look like it's being rendered properly. Your DrawPrimitives call probably isn't feeding the graphics card the right data (either your vertex/index buffers are filled in wrong or you have the primitive type/count wrong). Try rendering it in wireframe mode, you should be able to see the triangles that are getting distorted, producing these artifacts.
As for the ground - I will look some more through the code and see if I can think of anything.

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