I am pulling my hair out over this mouse picking thing. I do not know if the problem lies in my Ray calculation or my BoundingSpheres, anyway here's the code for my ray calculations:
public Ray CalculateRay(InputManager input)
{
Vector3 nearSource = new Vector3(input.CurrentMousePosition, 0f);
Vector3 farSource = new Vector3(input.CurrentMousePosition, 1f);
Vector3 nearPoint = Engine.Device.Viewport.Unproject(nearSource, _projectionMatrix,
_viewMatrix, Matrix.Identity);
Vector3 farPoint = Engine.Device.Viewport.Unproject(farSource,
_projectionMatrix, _viewMatrix, Matrix.Identity);
Vector3 direction = farPoint - nearPoint;
direction.Normalize();
return new Ray(nearPoint, direction);
}
and for the intersection check:
public bool RayIntersectsModel()
{
foreach (ModelMesh mesh in _model.Meshes)
{
BoundingSphere sphere = mesh.BoundingSphere;
sphere.Center = _position;
Ray ray = Engine.Camera.CalculateRay(Engine.Input);
if (sphere.Intersects(ray) != null)
{
return true;
}
}
return false;
}
It's not like it isn't working at all but it seems to be very inaccurate... or something. The models are just spheres, very simple. Any help or insight would be greatly appreciated!
Thanks!
Well, when I was transforming my bounding sphere I was first applying the world matrix then the bone transforms. This seems to put the bounding sphere in the wrong place. Switching it to first applying the bone transforms THEN the world matrix did it.
Related
I am new to AR, I am working on an APP using ARCore using this one AR-REMOTE-SUPPORT
When I am drawing it from my screen it is creating default android anchor, I want line instead of default android anchor.
How can I achieve this.
here is the function which is placing Anchors on the screen
public void onDrawFrame(GL10 gl) {
// Clear screen to notify driver it should not load any pixels from previous frame.
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
if (mSession == null) {
return;
}
// Notify ARCore session that the view size changed so that the perspective matrix and
// the video background can be properly adjusted.
mDisplayRotationHelper.updateSessionIfNeeded(mSession);
try {
// Obtain the current frame from ARSession. When the configuration is set to
// UpdateMode.BLOCKING (it is by default), this will throttle the rendering to the
// camera framerate.
Frame frame = mSession.update();
Camera camera = frame.getCamera();
// Handle taps. Handling only one tap per frame, as taps are usually low frequency
// compared to frame rate.
MotionEvent tap = queuedSingleTaps.poll();
if (tap != null && camera.getTrackingState() == TrackingState.TRACKING) {
for (HitResult hit : frame.hitTest(tap)) {
// Check if any plane was hit, and if it was hit inside the plane polygon
Trackable trackable = hit.getTrackable();
// Creates an anchor if a plane or an oriented point was hit.
if ((trackable instanceof Plane && ((Plane) trackable).isPoseInPolygon(hit.getHitPose()))
|| (trackable instanceof Point
&& ((Point) trackable).getOrientationMode()
== Point.OrientationMode.ESTIMATED_SURFACE_NORMAL)) {
// Hits are sorted by depth. Consider only closest hit on a plane or oriented point.
// Cap the number of objects created. This avoids overloading both the
// rendering system and ARCore.
if (anchors.size() >= 250) {
anchors.get(0).detach();
anchors.remove(0);
}
// Adding an Anchor tells ARCore that it should track this position in
// space. This anchor is created on the Plane to place the 3D model
// in the correct position relative both to the world and to the plane.
anchors.add(hit.createAnchor());
break;
}
}
}
// Draw background.
mBackgroundRenderer.draw(frame);
// If not tracking, don't draw 3d objects.
if (camera.getTrackingState() == TrackingState.PAUSED) {
return;
}
// Get projection matrix.
float[] projmtx = new float[16];
camera.getProjectionMatrix(projmtx, 0, 0.1f, 100.0f);
// Get camera matrix and draw.
float[] viewmtx = new float[16];
camera.getViewMatrix(viewmtx, 0);
// Compute lighting from average intensity of the image.
final float lightIntensity = frame.getLightEstimate().getPixelIntensity();
if (isShowPointCloud()) {
// Visualize tracked points.
PointCloud pointCloud = frame.acquirePointCloud();
mPointCloud.update(pointCloud);
mPointCloud.draw(viewmtx, projmtx);
// Application is responsible for releasing the point cloud resources after
// using it.
pointCloud.release();
}
// Check if we detected at least one plane. If so, hide the loading message.
if (mMessageSnackbar != null) {
for (Plane plane : mSession.getAllTrackables(Plane.class)) {
if (plane.getType() == Plane.Type.HORIZONTAL_UPWARD_FACING
&& plane.getTrackingState() == TrackingState.TRACKING) {
hideLoadingMessage();
break;
}
}
}
if (isShowPlane()) {
// Visualize planes.
mPlaneRenderer.drawPlanes(
mSession.getAllTrackables(Plane.class), camera.getDisplayOrientedPose(), projmtx);
}
// Visualize anchors created by touch.
float scaleFactor = 1.0f;
for (Anchor anchor : anchors) {
if (anchor.getTrackingState() != TrackingState.TRACKING) {
continue;
}
// Get the current pose of an Anchor in world space. The Anchor pose is updated
// during calls to session.update() as ARCore refines its estimate of the world.
anchor.getPose().toMatrix(mAnchorMatrix, 0);
// Update and draw the model and its shadow.
mVirtualObject.updateModelMatrix(mAnchorMatrix, mScaleFactor);
//mVirtualObjectShadow.updateModelMatrix(mAnchorMatrix, scaleFactor);
mVirtualObject.draw(viewmtx, projmtx, lightIntensity);
mVirtualObjectShadow.draw(viewmtx, projmtx, lightIntensity);
}
sendARViewMessage();
} catch (Throwable t) {
// Avoid crashing the application due to unhandled exceptions.
Log.e(TAG, "Exception on the OpenGL thread", t);
}
}
Any help would be appreciated
TIA
One simple way to draw a line in ARCore is to create it between two anchor points.
The line itself is generally a 3D object also.
Here is a tested working example, based on the nice approach in this answer: https://stackoverflow.com/a/52816504/334402
private void drawLine(AnchorNode node1, AnchorNode node2) {
//Draw a line between two AnchorNodes (adapted from https://stackoverflow.com/a/52816504/334402)
Log.d(TAG,"drawLine");
Vector3 point1, point2;
point1 = node1.getWorldPosition();
point2 = node2.getWorldPosition();
//First, find the vector extending between the two points and define a look rotation
//in terms of this Vector.
final Vector3 difference = Vector3.subtract(point1, point2);
final Vector3 directionFromTopToBottom = difference.normalized();
final Quaternion rotationFromAToB =
Quaternion.lookRotation(directionFromTopToBottom, Vector3.up());
MaterialFactory.makeOpaqueWithColor(getApplicationContext(), new Color(0, 255, 244))
.thenAccept(
material -> {
/* Then, create a rectangular prism, using ShapeFactory.makeCube() and use the difference vector
to extend to the necessary length. */
Log.d(TAG,"drawLine insie .thenAccept");
ModelRenderable model = ShapeFactory.makeCube(
new Vector3(.01f, .01f, difference.length()),
Vector3.zero(), material);
/* Last, set the world rotation of the node to the rotation calculated earlier and set the world position to
the midpoint between the given points . */
Anchor lineAnchor = node2.getAnchor();
nodeForLine = new Node();
nodeForLine.setParent(node1);
nodeForLine.setRenderable(model);
nodeForLine.setWorldPosition(Vector3.add(point1, point2).scaled(.5f));
nodeForLine.setWorldRotation(rotationFromAToB);
}
);
}
You can see the full source here: https://github.com/mickod/LineView
I'm working with XNA and a have a problem.
A basic problem, but argh !!!
I want to draw a ocean, BASIC ocean, just a plane, blue and transparent.
just a plane.
I have try with Vertex, with models and textures.
How tha alpha channel work in XNA ? StencilState, DepthBuffer, nothing would work.
Can you explain how to do this ?
Use VertexPositionColor enough ?
Excuse me, but I am looking for a long time.
class Ocean
{
Effect shader0;
public Vector3 Position;
GraphicsDevice Graphics;
Camera camera;
Model Mesh;
Texture2D waterTexture;
Rectangle screen;
Texture2D test;
public Ocean(Vector3 pos, int size, GraphicsDevice gra, Camera cam, ContentManager content)
{
Graphics = gra;
shader0 = content.Load<Effect>("Ocean");
//shader0 = new BasicEffect(this.Graphics);
waterTexture = content.Load<Texture2D>("Images/shaderUnderwater");
screen = new Rectangle(0, 0, this.Graphics.Viewport.Width, this.Graphics.Viewport.Height);
Position = pos;
Mesh = content.Load<Model>("Models/ocean");
camera = cam;
foreach (ModelMesh mesh in this.Mesh.Meshes)
{
foreach (ModelMeshPart part in mesh.MeshParts)
{
part.Effect = shader0;
}
}
}
bool underWater;
Vector3 lightDirection = new Vector3(-1.0f, -1.0f, -1.0f);
public void Draw(SpriteBatch spriteBatch, Player player)
{
Matrix world = Matrix.CreateScale(100f) * Matrix.CreateRotationX(MathHelper.ToRadians(-90f)) * Matrix.CreateTranslation(Position);
//this.shader0.EnableDefaultLighting();
this.shader0.Parameters["World"].SetValue(world);
this.shader0.Parameters["View"].SetValue(player.Camera.View);
this.shader0.Parameters["Projection"].SetValue(player.Camera.Projection);
// Dessin du model
foreach (ModelMesh mesh in this.Mesh.Meshes)
{
foreach (Effect effect in mesh.Effects)
{
effect.CurrentTechnique = effect.Techniques["Textured"];
effect.Parameters["DiffuseColor"].SetValue(new Vector4(1f, 0.2f, 0.2f, 1f) ); // a reddish light
effect.Parameters["DiffuseLightDirection"].SetValue(new Vector3(1, 0, 0) ); // coming along the x-axis
effect.Parameters["SpecularColor"].SetValue(new Vector4(0, 1, 0 ,1f) ); // with green highlights
effect.Parameters["World"].SetValue(world);
effect.Parameters["View"].SetValue(player.Camera.View);
effect.Parameters["Projection"].SetValue(player.Camera.Projection);
}
mesh.Draw();
}
this.Graphics.BlendState = BlendState.Opaque;
//Effet
if (camera.Position.Y < Position.Y)
spriteBatch.Draw(this.waterTexture, this.screen, Color.White);
}
public void Update(GameTime gameTime)
{
}
void onWater()
{
underWater = true;
}
}
}
If you are using the BasicEffect to render the ocean, then BasicEffect has an Alpha property, which affects the transparency. Please see here: http://msdn.microsoft.com/en-us/library/microsoft.xna.framework.graphics.basiceffect.alpha.aspx
You can use BasicEffect to create transparency with any way that you are using for rendering your model.
Please, tell me what I'm doing wrongly:
that's my Camera class
public class Camera
{
public Matrix view;
public Matrix world;
public Matrix projection;
public Vector3 position;
public Vector3 target;
public float fov;
public Camera(Vector3 pos, Vector3 tar)
{
this.position = pos;
this.target = tar;
view = Matrix.LookAtLH(position, target, Vector3.UnitY);
projection = Matrix.PerspectiveFovLH(fov, 1.6f, 0.001f, 100.0f);
world = Matrix.Identity;
}
}
that's my Constant buffer struct:
struct ConstantBuffer
{
internal Matrix mWorld;
internal Matrix mView;
internal Matrix mProjection;
};
and here I'm drawing the triangle and setting camera:
x+= 0.01f;
camera.position = new Vector3(x, 0.0f, 0.0f);
camera.view = Matrix.LookAtLH(camera.position, camera.target, Vector3.UnitY);
camera.projection = Matrix.PerspectiveFovLH(camera.fov, 1.6f, 0.0f, 100.0f);
var buffer = new Buffer(device, new BufferDescription
{
Usage = ResourceUsage.Default,
SizeInBytes = sizeof(ConstantBuffer),
BindFlags = BindFlags.ConstantBuffer
});
////////////////////////////// camera setup
ConstantBuffer cb;
cb.mProjection = Matrix.Transpose(camera.projection);
cb.mView = Matrix.Transpose(camera.view);
cb.mWorld = Matrix.Transpose(camera.world);
var data = new DataStream(sizeof(ConstantBuffer), true, true);
data.Write(cb);
data.Position = 0;
context.UpdateSubresource(new DataBox(0, 0, data), buffer, 0);
//////////////////////////////////////////////////////////////////////
// set the shaders
context.VertexShader.Set(vertexShader);
context.PixelShader.Set(pixelShader);
// draw the triangle
context.Draw(4, 0);
swapChain.Present(0, PresentFlags.None);
Please, if you can see what's wrong, tell me! :) I have spent two days writing this already..
Attempt the second:
#paiden I initialized fov now ( thanks very much :) ) but still no effect (now it's fov = 1.5707963267f;) and #Nico Schertler , thank you too, I put it in use by
context.VertexShader.SetConstantBuffer(buffer, 0);
context.PixelShader.SetConstantBuffer(buffer, 0);
but no effect still... probably my .fx file is wrong? for what purpose do I need this:
cbuffer ConstantBuffer : register( b0 ) { matrix World; matrix View; matrix Projection; }
Attepmpt the third:
#MHGameWork
Thank you very much too, but no effect still ;)
If anyone has 5 minutes time, I can just drop source code to his/her e-mail and then we will publish the answer... I guess it will help much to some newbies like me :)
unsafe
{
x+= 0.01f;
camera.position = new Vector3(x, 0.0f, 0.0f);
camera.view = Matrix.LookAtLH(camera.position, camera.target, Vector3.UnitY);
camera.projection = Matrix.PerspectiveFovLH(camera.fov, 1.6f, 0.01f, 100.0f);
var buffer = new Buffer(device, new BufferDescription
{
Usage = ResourceUsage.Default,
SizeInBytes = sizeof(ConstantBuffer),
BindFlags = BindFlags.ConstantBuffer
});
THE PROBLEM NOW - I SEE MY TRIANGLE BUT THE CAMERA DOESN'T MOVE
You have set your camera's nearplane to 0. This makes all the value in your matrix divide by zero, so you get a matrix filled with 'NAN's
Use a near plane value of about 0.01 in your case, it will solve the problem
I hope you still need help. Here is my camera class, which can be used, and can be easily moved around the scene using mouse/keyboard.
http://pastebin.com/JtiUSiHZ
Call the "TakeALook()" method in each frame (or when you move the camera).
You can move around it with the "CameraMove" method. It takes a Vector3 - where you want to move your camera (dont give it huge values, I use 0,001f for each frame)
And with the "CameraRotate()" you can turn it around - it take a Vector2 as a Left-Right and Up-Down rotation.
Its pretty easy. I use EventHandlers to call there two function, but feel free to edit as you wish.
I made a 2D isometric renderer. It works fine but now I want to show my scene from 4 differents point of view (NO NW SE SW) but, on a 90° rotation, my camera cannot keep the center of my scene on screen.
What's working :
I calcul new projection of scene to match the new viewport (x y z in my world).
I reorganise part of my scene(chunk) to draw them in a correct order
I reorganise 'tiles' of 'chunks' to draw them in a correct order
I can keep the correct center with a 180 degres rotation.
What's do not working :
I cannot find a correct translation to apply to my camera after a 90 degres rotation.
What I know :
To keep the same center on a 180° rotation with my camera I have to do this :
camera.Position -= new Vector2(2 * camera.Position.X + camera.Width, 2 * camera.Position.Y + camera.Height);
Illustration
If the center of your map is origo (0,0,0), this gets easy:
First you store your default camera position in a Vector3 CameraOffset, then you calculate position using a rotation-matrix. 90* in redians is half a Pi, so we will use PiOverTwo. We will also use an enum to decide what direction to be pointing, so you can say
Camera.Orientation = Orientation.East;
and the camera should fix itself :)
public enum Orientation
{
North, East, South, West
}
in camera:
public Vector3 Position { get; protected set; }
Vector3 _CameraOffset = new Vector3(0, 20, 20);
public Vector3 CameraOffset
{
get
{
return _Orientation;
}
set
{
_Orientation = value;
UpdateOrientation();
}
}
Orientation _Orientation = Orientation.North;
public Orientation Orientation
{
get
{
return _Orientation;
}
set
{
_Orientation = value;
UpdateOrientation();
}
}
private void UpdateOrientation()
{
Position = Vector3.Transform(CameraOffset, Matrix.CreateRotationY(MathHelper.PiOverTwo * (int)Orientation));
}
If you want a gliding movement between positions, I think I can help too ;)
If your camera does not focus on Vector3.Zero and should not rotate around it, you just need to change:
Position = Vector3.Transform(CameraOffset, Matrix.CreateRotationY(MathHelper.PiOverTwo * (int)Orientation));
to:
Position = Vector3.Transform(CameraOffset, Matrix.CreateRotationY(MathHelper.PiOverTwo * (int)Orientation) * Matrix.CreateTranslation(FocusPoint));
Here, FocusPoint is the point in 3D that you rotate around (your worlds center). And now you also know how to let your camera move around, if you call UpdateOrientation() in your Camera.Update() ;)
EDIT; So sorry, totally missed the point that you use 2D. I'll be back later to see if I can help :P
I want to use class BoundingBox in XNA 4.0 to check collision between cube with cube or cube with sphere? I know about BoundingSphere but I don't know use to BoundingBox. Have any good sample about this! Thanks!
You make boundingboxes like this:
Vector3 CenterOfBox = new Vector3(10,10,10);
int Width = 10;
int Height = 10;
BoundingBox BoundingBox1 = new BoundingBox(CenterOfBox - new Vector(Width/2,Height/2,Width/2),CenterOfBox + new Vector(Width/2,Height/2,Width/2));
More info: http://msdn.microsoft.com/en-us/library/microsoft.xna.framework.boundingbox.boundingbox.aspx
Lets say you have BoundingBox1 and BoundingBox2
Then you can check if they intersect with:
if(BoundingBox1.Intersect(BoundingBox2))
{
//They hit
}
else
{
//They don't hit
}
You can also pass a BoundingSphere in the Intersect function
More info: http://msdn.microsoft.com/en-us/library/microsoft.xna.framework.boundingbox.intersects.aspx