DirectXMath Unproject on the wrong axis - camera

EDIT: Solved the issue, see my own answer
Recently I've been working on a 3D world editor that will be using picking to raise or lower terrain. I'm using camera unprojection and ray casting to find the world position of the mouse screen coordinates.
However, it seems like the ray is on the wrong axis. As I remember, the ray that is supposed to come out of unproject should be coming straight from the camera.
Here's an example of what it currently looks like.
My question is, why is the ray over the Y-axis when it's supposed to be over the Z-axis?
XMFLOAT3 D3D11Camera::Unproject(const float& px, const float& py, const float& pz)
{
const XMFLOAT2& res = D3D11RenderSettings::Instance()->resolution();
XMVECTOR coords = XMVector3Unproject(XMVectorSet(px, res.y - py, pz, 0.0f), 0.0f, 0.0f, res.x, res.y, near_plane_, far_plane_, projection_, view_, XMMatrixIdentity());
XMFLOAT3 to_ret;
XMStoreFloat3(&to_ret, coords);
return to_ret;
}
This is the unprojection code..
And this is how I'm using it
projectRay: function()
{
var p = Mouse.position(MousePosition.Relative);
p.x = (p.x + RenderSettings.resolution().w / 2);
p.y = (p.y + RenderSettings.resolution().h / 2);
var unprojA = this._camera.unproject(p.x, p.y, 0);
var unprojB = this._camera.unproject(p.x, p.y, 1);
var dir = Vector3D.normalise(Vector3D.sub(unprojB, unprojA));
var ray = Ray.construct(unprojA, dir);
var p1 = ray.origin;
var p2 = Vector3D.add(ray.origin, Vector3D.mul(ray.direction, 1000));
RenderTargets.ui.drawLine(p1.x, p1.y, p1.z, 1, 0, 0, p2.x, p2.y, p2.z, 1, 0, 0);
return ray;
}
Cheers!

Stupidity aside, I'm working with both an inverted Y-axis coordinate system and a default -- non inverted -- one. It seemed like it was a ray oriented vertically, but in fact it was a ray that was oriented in the direction of '/' while it was supposed to be oriented like '\'. Multiplying the Y component of the result by -1 solved the issue.

Related

game maker GML twin stick shooter analogue controller

I am trying to make a twin stick shooter but I cannot get right analogue stick to shoot in the correct direction. Here is the code I have the weapon sits on top of the player and rotates. It all works fine just need to know how to get the correct angle of the right stick and fire a bullet in that direction.
//set depth
depth = -y + obj_player.y_off_set - 1;
//analog left stick face direction
var h_point = gamepad_axis_value(0, gp_axisrh);
var v_point = gamepad_axis_value(0, gp_axisrv);
if ((h_point != 0) || (v_point != 0))
{
var pdir = point_direction(0, 0, h_point, v_point);
var dif = angle_difference(pdir, image_angle);
image_angle += median(-20, dif, 20);
}
//flips gun when turning
if(gamepad_axis_value(0, gp_axisrh) < -0.5)
{
image_yscale = -1;
}else if (gamepad_axis_value(0, gp_axisrh) > 0.5)
{
image_yscale = 1;
}
//fireing
fire = gamepad_button_check_pressed(0, gp_shoulderr) && alarm[0] <= 0;
if(fire)
{
var face = point_direction(0, 0, gp_axisrh, gp_axisrv);
var p = instance_create(x, y, obj_projectile);
var xforce = lengthdir_x(20, face*90);
var yforce = lengthdir_x(20, face*90);
p.creator = id;
with (p){
physics_apply_impulse(x, y, xforce, yforce);
}
as this question is a couple months old, I imagine you found the solution to your problem, but hopefully this answer can help anyone else stuck on the issue.
Based on the code snippet you provided, it looks like if you remove the *90 from the lengthdir_ functions, your code should work.
Here is the code I wrote in my game to get 360 degree shooting working with the right analog stick (this code lives in the step event of the Player object):
if (shooting) {
bullet = instance_create(x, y, Bullet);
with (bullet) {
haxis = gamepad_axis_value(0, gp_axisrh);
vaxis = gamepad_axis_value(0, gp_axisrv);
dir = point_direction(0, 0, haxis, vaxis);
physics_apply_impulse(x, y, lengthdir_x(50, gp_axisrh), lengthdir_y(50, dir));
}
}
This particular thread on the GameMaker community forums was quite helpful as I researched how to solve this issue in my game.

Three.js, Camera rotation around a point

I'm trying to make a camera rotation and zoom around a point.
I don't want to use THREE.TrackBallControls because as i see, it only modify the fov when zooming, it is not what i want.
I'm using this simple equation : http://en.wikipedia.org/wiki/Sphere#Equations_in. To compute a point on the sphere, this point will be the position of the camera.
In three.js
var point = new THREE.Vector3(
radius * Math.cos(theta) * Math.sin(phi),
radius * Math.sin(theta) * Math.sin(phi),
radius * Math.cos(phi)
);
point.add(center);
To manipulate it, i use :
left mouse, for rotation : x coord === theta and y coord === phi
middle mouse, for zooming : zoom in/out === radius
It doesn't work well, especially for 'phi' rotation, maybe because it's define between 0 and PI.
Maybe there is a better solution using Quaternion.Slerp ?
edit :
My camera :
aspectRatio = container.offsetWidth / container.offsetHeight;
camera = new THREE.OrthographicCamera( -aspectRatio * viewSize / 2, aspectRatio * viewSize / 2, viewSize / 2, -viewSize / 2, -10, 10 );
camera.position.x = 0.004;
camera.position.y = 0.004;
camera.position.z = 0.004;
camera.lookAt(new THREE.Vector3(0, 0, 0))
scene.add(camera);
My OrbitControls :
controls = new THREE.OrbitControls ( camera );
controls.rotateSpeed = 1.0;
controls.zoomSpeed = 1.2;
controls.keyPanSpeed = 0.8;
controls.noZoom = false;
controls.noPan = false;
when using left mouse (rotation) the camera.position change.
when using middle mouse (zoom) the camera.position is still the same.
check made in the render function :
function render() {
// update camera controls
controls.update();
console.log(camera.position);
// actually render the scene
renderer.render( scene, camera );
}

Three.js - Fisheye effect

So, I've messed around with three.js, works out great. The only thing I can't figure out, is how to make a camera with a real fisheye effect.
How is that possible? camera.setLens()?
The fish eye effect can be achieved using Giliam de Carpentier's shader for lens distortion.
Shader code:
function getDistortionShaderDefinition()
{
return {
uniforms: {
"tDiffuse": { type: "t", value: null },
"strength": { type: "f", value: 0 },
"height": { type: "f", value: 1 },
"aspectRatio": { type: "f", value: 1 },
"cylindricalRatio": { type: "f", value: 1 }
},
vertexShader: [
"uniform float strength;", // s: 0 = perspective, 1 = stereographic
"uniform float height;", // h: tan(verticalFOVInRadians / 2)
"uniform float aspectRatio;", // a: screenWidth / screenHeight
"uniform float cylindricalRatio;", // c: cylindrical distortion ratio. 1 = spherical
"varying vec3 vUV;", // output to interpolate over screen
"varying vec2 vUVDot;", // output to interpolate over screen
"void main() {",
"gl_Position = projectionMatrix * (modelViewMatrix * vec4(position, 1.0));",
"float scaledHeight = strength * height;",
"float cylAspectRatio = aspectRatio * cylindricalRatio;",
"float aspectDiagSq = aspectRatio * aspectRatio + 1.0;",
"float diagSq = scaledHeight * scaledHeight * aspectDiagSq;",
"vec2 signedUV = (2.0 * uv + vec2(-1.0, -1.0));",
"float z = 0.5 * sqrt(diagSq + 1.0) + 0.5;",
"float ny = (z - 1.0) / (cylAspectRatio * cylAspectRatio + 1.0);",
"vUVDot = sqrt(ny) * vec2(cylAspectRatio, 1.0) * signedUV;",
"vUV = vec3(0.5, 0.5, 1.0) * z + vec3(-0.5, -0.5, 0.0);",
"vUV.xy += uv;",
"}"
].join("\n"),
fragmentShader: [
"uniform sampler2D tDiffuse;", // sampler of rendered scene?s render target
"varying vec3 vUV;", // interpolated vertex output data
"varying vec2 vUVDot;", // interpolated vertex output data
"void main() {",
"vec3 uv = dot(vUVDot, vUVDot) * vec3(-0.5, -0.5, -1.0) + vUV;",
"gl_FragColor = texture2DProj(tDiffuse, uv);",
"}"
].join("\n")
};
}
One way to setup the effect using effect composer (assuming scene and renderer have been been created):
// Create camera
camera = new THREE.PerspectiveCamera( 100, window.innerWidth / window.innerHeight, 1, 1000000 );
camera.position.z = 800;
// Create effect composer
composer = new THREE.EffectComposer( renderer );
composer.addPass( new THREE.RenderPass( scene, camera ) );
// Add distortion effect to effect composer
var effect = new THREE.ShaderPass( getDistortionShaderDefinition() );
composer.addPass( effect );
effect.renderToScreen = true;
// Setup distortion effect
var horizontalFOV = 140;
var strength = 0.5;
var cylindricalRatio = 2;
var height = Math.tan(THREE.Math.degToRad(horizontalFOV) / 2) / camera.aspect;
camera.fov = Math.atan(height) * 2 * 180 / 3.1415926535;
camera.updateProjectionMatrix();
effect.uniforms[ "strength" ].value = strength;
effect.uniforms[ "height" ].value = height;
effect.uniforms[ "aspectRatio" ].value = camera.aspect;
effect.uniforms[ "cylindricalRatio" ].value = cylindricalRatio;
Following script are needed and they can be found for example from three.js GitHub page:
<script src="examples/js/postprocessing/EffectComposer.js"></script>
<script src="examples/js/postprocessing/RenderPass.js"></script>
<script src="examples/js/postprocessing/MaskPass.js"></script>
<script src="examples/js/postprocessing/ShaderPass.js"></script>
<script src="examples/js/shaders/CopyShader.js"></script>
Link to Giliam's example: http://www.decarpentier.nl/downloads/lensdistortion-webgl/lensdistortion-webgl.html
Link to Giliam's article about lens distortion: http://www.decarpentier.nl/lens-distortion
Image of my test where lens distortion effect is used:
Put a camera inside a reflective sphere. Make sure the sphere is double sided. Parent the camera and sphere together if you want to move it around your scene. Works like a charm:
http://tileableart.com/code/NOCosmos/test.html
borrowed from:
http://mrdoob.github.io/three.js/examples/webgl_materials_cubemap_dynamic2.html
cubeCamera = new THREE.CubeCamera( 1, 3000, 1024);
cubeCamera.renderTarget.minFilter = THREE.LinearMipMapLinearFilter;
scene.add( cubeCamera );
camParent.add(cubeCamera);
var material = new THREE.MeshBasicMaterial( { envMap: cubeCamera.renderTarget } );
material.side = THREE.DoubleSide;
sphere = new THREE.Mesh( new THREE.SphereGeometry( 2, 60, 30 ), material );
It's possible to get the fisheye effect with a high Field of View.
var fishCamera = new THREE.PerspectiveCamera( 110, window.innerWidth / window.innerHeight, 1, 1100 );
var normalCamera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 1100 );
or set
camera.fov = 110
camera.updateProjectionMatrix();
Live Example here:
http://mrdoob.github.com/three.js/examples/canvas_geometry_panorama_fisheye.html
One way is to set a large field of view on the camera:
new THREE.PerspectiveCamera(140, ... )
This will not technically be a fisheye effect, but it may be the effect you're looking for.
In a real camera lens, getting a large field of view without distorsion would likely make the lens pretty expensive, but in computer graphics, it's the easy way.
A real fisheye lens distorts the image so that straight line become curved, like in this image:
If you want to create an actual fisheye effect with this kind of distorsion, you would have to modify the geometry, as in Three.js's fisheye example. In that example, the geometry is actually modified beforehand, but for a more advanced scene, you'd want to use a vertex shader to update the vertices on the fly.
A wide angle lens generally have a very low focus length.
To achieve an extreme wide angle we need to reduce focus length.
Note that fish eye lens is an extreme wide angle lens.
To reduce focus length(or to achieve extreme wide angles), one can just increase FOV (field of view), as FOV is inversely proportional to focus length.
example:
var camera_1 = new THREE.PerspectiveCamera( 45, width / height, 1, 1000 );
var camera_2 = new THREE.PerspectiveCamera( 80, width / height, 1, 1000 );
Here camera_2 is a wider angle setup.
Note
To achieve desired effect, one may have to adjust camera position.

Android - Trying to gradually fill a circle bottom to top

I'm trying to fill a round circle (transparent other than the outline of the circle) in an ImageView.
I have the code working:
public void setPercentage(int p) {
if (this.percentage != p ) {
this.percentage = p;
this.invalidate();
}
}
#Override public void onDraw(Canvas canvas) {
Canvas tempCanvas;
Paint paint;
Bitmap bmCircle = null;
if (this.getWidth() == 0 || this.getHeight() == 0 )
return ; // nothing to do
mergedLayersBitmap = Bitmap.createBitmap(this.getWidth(), this.getHeight(), Bitmap.Config.ARGB_8888);
tempCanvas = new Canvas(mergedLayersBitmap);
paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setStyle(Paint.Style.FILL_AND_STROKE);
paint.setFilterBitmap(false);
bmCircle = drawCircle(this.getWidth(), this.getHeight());
tempCanvas.drawBitmap(bmCircle, 0, 0, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
tempCanvas.clipRect(0,0, this.getWidth(), (int) FloatMath.floor(this.getHeight() - this.getHeight() * ( percentage/100)));
tempCanvas.drawColor(0xFF660000, PorterDuff.Mode.CLEAR);
canvas.drawBitmap(mergedLayersBitmap, null, new RectF(0,0, this.getWidth(), this.getHeight()), new Paint());
canvas.drawBitmap(mergedLayersBitmap, 0, 0, new Paint());
}
static Bitmap drawCircle(int w, int h) {
Bitmap bm = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(bm);
Paint p = new Paint(Paint.ANTI_ALIAS_FLAG);
p.setColor(drawColor);
c.drawOval(new RectF(0, 0, w, h), p);
return bm;
}
It kind of works. However, I have two issues: I run out of memory quickly and the GC goes crazy. How can I utilize the least amount of memory for this operation?
I know I Shouldn't be instantiating objects in onDraw, however I'm not sure where to draw then. Thank you.
pseudo would look something like this.
for each pixel inside CircleBitmap {
if (pixel.y is < Yboundary && pixelIsInCircle(pixel.x, pixel.y)) {
CircleBitmap .setPixel(x, y, Color.rgb(45, 127, 0));
}
}
that may be slow, but it would work, and the smaller the circle the faster it would go.
just know the basics, bitmap width and height, for example 256x256, the circles radius, and to make things easy make the circle centered at 128,128. then as you go pixel by pixel, check the pixels X and Y to see if it falls inside the circle, and below the Y limit line.
then just use:
CircleBitmap .setPixel(x, y, Color.rgb(45, 127, 0));
edit: to speed things up, don't even bother looking at the pixels above the Y limit.
in case if you want to see another solution (perhaps cleaner), look at this link, filling a circle gradually from bottom to top android

Rotating camera around the X-axis (three.js)

I am trying to rotate the camera around to X-axis of the scene.
At this point my code is like this:
rotation += 0.05;
camera.position.y = Math.sin(rotation) * 500;
camera.position.z = Math.cos(rotation) * 500;
This makes the camera move around but during the rotation something weird happens and either the camera flips, or it skips some part of the imaginary circle it's following.
You have only provided a snippet of code, so I have to make some assumptions about what you are doing.
This code:
rotation += 0.05;
camera.position.x = 0;
camera.position.y = Math.sin(rotation) * 500;
camera.position.z = Math.cos(rotation) * 500;
camera.lookAt( scene.position ); // the origin
will cause the "flipping" you refer to because the camera is trying to remain "right side up", and it will quickly change orientation as it passes over the "north pole."
If you offset the camera's x-coordinate like so,
camera.position.x = 200;
the camera behavior will appear more natural to you.
Three.js tries to keep the camera facing up. When you pass 0 along the z-axis, it'll "fix" the camera's rotation. You can just check and reset the camera's angle manually.
camera.lookAt( scene.position ); // the origin
if (camera.position.z < 0) {
camera.rotation.z = 0;
}
I'm sure this is not the best solution, but if anyone else runs across this question while playing with three.js (like I just did), it'll give one step further.
This works for me, I hope it helps.
Rotating around X-Axis:
var x_axis = new THREE.Vector3( 1, 0, 0 );
var quaternion = new THREE.Quaternion;
camera.position.applyQuaternion(quaternion.setFromAxisAngle(x_axis, rotation_speed));
camera.up.applyQuaternion(quaternion.setFromAxisAngle(x_axis, rotation_speed));
Rotating around Y-Axis:
var y_axis = new THREE.Vector3( 0, 1, 0 );
camera.position.applyQuaternion(quaternion.setFromAxisAngle(y_axis, angle));
Rotating around Z-Axis:
var z_axis = new THREE.Vector3( 0, 0, 1 );
camera.up.applyQuaternion(quaternion.setFromAxisAngle(z_axis, angle));
I wanted to move my camera to a new location while having the camera look at a particular object, and this is what I came up with [make sure to load tween.js]:
/**
* Helper to move camera
* #param loc Vec3 - where to move the camera; has x, y, z attrs
* #param lookAt Vec3 - where the camera should look; has x, y, z attrs
* #param duration int - duration of transition in ms
**/
function flyTo(loc, lookAt, duration) {
// Use initial camera quaternion as the slerp starting point
var startQuaternion = camera.quaternion.clone();
// Use dummy camera focused on target as the slerp ending point
var dummyCamera = camera.clone();
dummyCamera.position.set(loc.x, loc.y, loc.z);
// set the dummy camera quaternion
var rotObjectMatrix = new THREE.Matrix4();
rotObjectMatrix.makeRotationFromQuaternion(startQuaternion);
dummyCamera.quaternion.setFromRotationMatrix(rotObjectMatrix);
dummyCamera.up.set(camera)
console.log(camera.quaternion, dummyCamera.quaternion);
// create dummy controls to avoid mutating main controls
var dummyControls = new THREE.TrackballControls(dummyCamera);
dummyControls.target.set(loc.x, loc.y, loc.z);
dummyControls.update();
// Animate between the start and end quaternions
new TWEEN.Tween(camera.position)
.to(loc, duration)
.onUpdate(function(timestamp) {
// Slerp the camera quaternion for smooth transition.
// `timestamp` is the eased time value from the tween.
THREE.Quaternion.slerp(startQuaternion, dummyCamera.quaternion, camera.quaternion, timestamp);
camera.lookAt(lookAt);
})
.onComplete(function() {
controls.target = new THREE.Vector3(scene.children[1].position-0.001);
camera.lookAt(lookAt);
}).start();
}
Example usage:
var pos = {
x: -4.3,
y: 1.7,
z: 7.3,
};
var lookAt = scene.children[1].position;
flyTo(pos, lookAt, 60000);
Then in your update()/render() function, call TWEEN.update();
Full example