How does the cpSpaceShapeQuery function work? I can not find any doc about it.
Andrea
Yeah... I never got around to documenting that... Sorry. Basically you create a body and shape (neither needs to be added to the space) and use that to query much like the other query functions.
This code snippet makes a copy of a body and shape on the stack and then simulates it out to it's first predicted collision point drawing the path as it goes.
cpBody body = *(originalBody);
cpPolyShape shape = *((cpPolyShape *)originalShape);
shape.shape.body = &body;
cpFloat dt = 1.0f/60.0f;
cpVect gravity = space->gravity;
int count = 0;
for(int i=0; i<300; i++){
cpBodyUpdatePosition(&body, dt);
cpBodyUpdateVelocity(&body, gravity, 1.0f, dt);
if(cpSpaceShapeQuery(space, (cpShape *)&shape, NULL, NULL)){
quads[count%maxQuads] = quad(body.p, body.rot, CGRectMake(0, 2*32, 64, 64), tsize);
count++;
break;
}
if(i%10==0){
quads[count%maxQuads] = quad(body.p, body.rot, rect, tsize);
count++;
}
}
Related
I'm trying to learn the Unity game engine. I'm trying to develop a mechanic. Objects are created from the object pool in a fixed location. However, when I make them child object of a different object and finish the process and deactivate them, the scale values of the reconstructed objects change. Why is this happening?
private IEnumerator Create_Green_Pizzas(List<Transform> pizzas)
{
int pizzaCount = 0;
while (pizzaCount < pizzas.Count)
{
currentColumn++;
if (currentColumn >= columnCount)
{
currentRow++;
currentColumn = 0;
}
if (currentRow >= rowCount)
{
pizzaLevel++;
currentRow = 0;
currentColumn = 0;
}
for (int i = 0; i < pizzas.Count; i++)
{
if (!pizzas[i].gameObject.activeInHierarchy)
{
pizzas[i].gameObject.SetActive(true);
pizzas[i].parent = pizzasParent;
pizzas[i].rotation = transform.rotation;
pizzas[i].position = initialSlotPosition + new Vector3(((pizzas[i].lossyScale.x) * currentColumn), (pizzaLevel * pizzas[i].lossyScale.y), ((-pizzas[i].lossyScale.z) * currentRow));
pizzas[i].GetComponent<MeshRenderer>().material.color = Color.green;
_player.collectableGreenPizzas.Add(pizzas[i]);
pizzaCount++;
yield return new WaitForSeconds(0.5f);
break;
}
}
}
}
Setting gameobject's the parent might be the cause, so instead of:
pizzas[i].parent = pizzasParent;
try instead:
pizzas[i].SetParent(pizzasParent, true);
You can find more info about this method Here
If a GameObject has a parent, they become part of the parent's referential, their transform is now a local transform that depends on the parent's transform.
This means that if a child transform has a scale of (1, 1, 1), has the same scale as its parent.
Here's a small clip that illustrates this, two sphere that are the same size while they both have a different scale.
However you can force the GameObject to preserve its coordinates and scale using this line :
child.SetParent(parent, true);
I have a list of sprite components in my game that represent three background sprite images which I would like to scroll infinitely. I initialize, update, and render the sprite components using the code below, however the sprites all move at different speeds and the game can slow down immensely at times, what is it that I am doing wrong?
Initializing:
List<SpriteComponent> bkgList = [];
bkgImage = await images.load('BGFull.png');
for (int i = 0; i < MAX_BKG_COUNT; i++) {
final spr = Sprite(bkgImage);
bkgList.add(SpriteComponent(
sprite: spr,
position: Vector2(640.0 * i, 0),
size: Vector2(640, 384)
));
}
Update:
for (int j = 0; j < bkgList.length; j++) {
bkgList[j].position.x -= 1.0;
if (bkgList[j].position.x < -640.0) {
bkgList.removeAt(0);
bkgList.add(SpriteComponent(
sprite: Sprite(bkgImage),
position: Vector2(bkgList.last.position.x + 640.0, 0),
size: Vector2(640, 384)
));
}
}
Render:
for (int z = 0; z < bkgList.length; z++) {
bkgList[z].render(canvas);
}
What you want to do for this is most likely to use the ParallaxComponent which you can find docs for here. For loading the spritesheet that you have in BGFull.png you can use the SpriteSheet class, and then pass in the images from there to the ParallaxComponent.
But from the code you have right now, the problem could be that you are not doing the initialization in the onLoad method, but I can't tell from your snippets.
I stumbled upon a strange problem in vuforia.When i request a camera image using CameraDevice.GetCameraImage(mypixelformat), the image returned is both flipped sideways and rotated 180 deg. Because of this, to obtain a normal image i have to first rotate the image and then flip it sideways.The approach i am using is simply iterating over pixels of the image and modifying them.This approach is very poor performance wise.Below is the code:
Texture2D image;
CameraDevice cameraDevice = Vuforia.CameraDevice.Instance;
Vuforia.Image vufImage = cameraDevice.GetCameraImage(pixelFormat);
image = new Texture2D(vufImage.Width, vufImage.Height);
vufImage.CopyToTexture(image);
Color32[] colors = image.GetPixels32();
System.Array.Reverse(colors, 0, colors.Length); //rotate 180deg
image.SetPixels32(colors); //apply rotation
image = FlipTexture(image); //flip sideways
//***** THE FLIP TEXTURE METHOD *******//
private Texture2D FlipTexture(Texture2D original, bool upSideDown = false)
{
Texture2D flipped = new Texture2D(original.width, original.height);
int width = original.width;
int height = original.height;
for (int col = 0; col < width; col++)
{
for (int row = 0; row < height; row++)
{
if (upSideDown)
{
flipped.SetPixel(row, (width - 1) - col, original.GetPixel(row, col));
}
else
{
flipped.SetPixel((width - 1) - col, row, original.GetPixel(col, row));
}
}
}
flipped.Apply();
return flipped;
}
To improve the performance i want to somehow schedule these pixel operations on the GPU, i have heard that a compute shader can be used, but i have no idea where to start.Can someone please help me write the same operations in a compute shader so that the GPU can handle them, Thankyou!.
The whole compute shader are new for me too, but i took the occasion to research it a little bit for myself too. The following works for flipping a texture vertically (rotating and flipping horizontally should be just a vertical flip).
Someone might have a more elaborate solution for you, but maybe this is enough to get you started.
The Compute shader code:
#pragma kernel CSMain
// Create a RenderTexture with enableRandomWrite flag and set it
// with cs.SetTexture
RWTexture2D<float4> Result;
Texture2D<float4> ImageInput;
float2 flip;
[numthreads(8,8,1)]
void CSMain (uint3 id : SV_DispatchThreadID)
{
flip = float2(512 , 1024) - id.xy ;
Result[id.xy] = float4(ImageInput[flip].x, ImageInput[flip].y, ImageInput[flip].z, 1.0);
}
and called from any script:
public void FlipImage()
{
int kernelHandle = shader.FindKernel("CSMain");
RenderTexture tex = new RenderTexture(512, 1024, 24);
tex.enableRandomWrite = true;
tex.Create();
shader.SetTexture(kernelHandle, "Result", tex);
shader.SetTexture(kernelHandle, "ImageInput", myTexture);
shader.Dispatch(kernelHandle, 512/8 , 1024 / 8, 1);
RenderTexture.active = tex;
result.ReadPixels(new Rect(0, 0, tex.width, tex.height), 0, 0);
result.Apply();
}
This takes an input Texture2D, flips it in the shader, applies it to a RenderTexture and to a Texture2D, whatever you need.
Note that the image sizes are hardcoded in my instance and should be replaced by whatever size you need. (for within the shader use shader.SetInt(); )
Attempting to get the user's height in Unity using the xbox kinect.
Below is my code and I cannot get the height.
This uses the KinectV2 interface.
// get User's height by KinectV2 and unity3D `enter code here`
float GetUserHeightByLeft(long userid)
{`enter code here`
float uheight=0.0f;
int[] joints = new int[9];
int head = (int)KinectInterop.JointType.Head;
joints[0] = head;
joints[1] = (int)KinectInterop.JointType.Neck;
int shoudlderCenter = (int)KinectInterop.JointType.SpineShoulder;
joints[2] = shoudlderCenter;
joints[3] = (int)KinectInterop.JointType.SpineMid;
joints[4] = (int)KinectInterop.JointType.SpineBase;
joints[5] = (int)KinectInterop.JointType.HipLeft;
joints[6] = (int)KinectInterop.JointType.KneeLeft;
joints[7] = (int)KinectInterop.JointType.AnkleLeft;
joints[8] = (int)KinectInterop.JointType.FootLeft;
int trackedcount = 0;
for (int i = 0; i < joints.Length; ++i)
{
if (KinectManager.Instance.IsJointTracked(userid, joints[i]))
{
++trackedcount;
}
}
//if all joints that I need have been tracked ,compute user's height
if (trackedcount == joints.Length)
{
for (int i = 0; i < joints.Length-1;++i)
{
if (KinectManager.Instance.IsJointTracked(userid, joints[i]))
{
Vector3 start= 100*KinectManager.Instance.GetJointKinectPosition(userid,joints[i]);
Vector3 end = 100*KinectManager.Instance.GetJointKinectPosition(userid,joints[i+1]);
uheight += Mathf.Abs(Vector3.Magnitude(end-start));
}
}
//some height kinectV2 can't get so I add it
uheight += 8;
}
return uheight;
}
Given your code I do see a few issues
The summation to get the total height requires all joints to be tracked at that time.
Why do you need all joints to be tracked for the height to be tracked? You should only need the head and the feet
You double check if each joint is tracked
using the left for every foot/knee/hip joint is going to give you math errors. They are offset in one direction (because our feet aren't in the center of our body)
I would track both right and left foot/knee/hip and then find the center of the two on the x axis.
If you're using the magnitude of two vectors and one knee is far in front of your hip it's going to give it an inflated value.
I would only use the y positions of your kinect joints to calculate the height.
I am newbie in Unity platform. I have 2D game that contains 10 boxes vertically following each other in chain. When a box goes off screen, I change its position to above of the box at the top. So the chain turns infinitely, like repeating Parallax Scrolling Background.
But I check if a box goes off screen by comparing its position with a specified float value. I am sharing my code below.
void Update () {
offSet = currentSquareLine.transform.position;
currentSquareLine.transform.position = new Vector2 (0f, -2f) + offSet;
Vector2 vectorOne = currentSquareLine.transform.position;
Vector2 vectorTwo = new Vector2 (0f, -54f);
if(vectorOne.y < vectorTwo.y) {
string name = currentSquareLine.name;
int squareLineNumber = int.Parse(name.Substring (11)) ;
if(squareLineNumber < 10) {
squareLineNumber++;
} else {
squareLineNumber = 1;
}
GameObject squareLineAbove = GameObject.Find ("Square_Line" + squareLineNumber);
offSet = (Vector2) squareLineAbove.transform.position + new Vector2(0f, 1.1f);
currentSquareLine.transform.position = offSet;
}
}
As you can see, when I compare vectorOne.y and vectorTwo.y, things get ugly. Some boxes lengthen and some boxes shorten the distance between each other even I give the exact vector values in the code above.
I've searched for a solution for a week, and tried lots of codes like Mathf.Approximate, Mathf.Round, but none of them managed to compare float values properly. If unity never compares float values in the way I expect, I think I need to change my way.
I am waiting for your godlike advices, thanks!
EDIT
Here is my screen. I have 10 box lines vertically goes downwards.
When Square_Line10 goes off screen. I update its position to above of Square_Line1, but the distance between them increases unexpectedly.
Okay, I found a solution that works like a charm.
I need to use an array and check them in two for loops. First one moves the boxes and second one check if a box went off screen like below
public GameObject[] box;
float boundary = -5.5f;
float boxDistance = 1.1f;
float speed = -0.1f;
// Update is called once per frame
void Update () {
for (int i = 0; i < box.Length; i++) {
box[i].transform.position = box[i].transform.position + new Vector3(0, speed, 0);
}
for (int i = 0; i < box.Length; i++)
{
if(box[i].transform.position.y < boundary)
{
int topIndex = (i+1) % box.Length;
box[i].transform.position = new Vector3(box[i].transform.position.x, box[topIndex].transform.position.y + boxDistance, box[i].transform.position.z);
break;
}
}
}
I attached it to MainCamera.
Try this solution:
bool IsApproximately(float a, float b, float tolerance = 0.01f) {
return Mathf.Abs(a - b) < tolerance;
}
The reason being that the tolerances in the internal compare aren't good to use. Change the tolerance value in a function call to be lower if you need more precision.