playing around with ARkit for the first time to place real world objects. getting the objects to go in at x,z (log/lat) seems to work ok but struggling with y (height) of objects. anyone got any example of height data being used?
any examples would help
y-axis in the positive will make the node go upwards (units in metres).
so if I want to position my node.... 1 metre in front of the camera and 10 metres high. You would set the position of the node below.
SCNVector3(x:float, y:float, z:float)
node.position = SCNVector3(0,10,-1)
Altitude is above sea level in meters. So if your location has altitude of 170m and you want your object to be floating in 10m, then you want to put altitude of 180.
Related
I am trying to place large 3D models (SCNNode) in ARSCNView using ARKit.
The approximate size is as follows :
I have been through the following links :
is-there-any-size-limitations-on-3d-files-loaded-using-arkit
load-large-3d-object-scn-file-in-arscnview-aspect-fit-in-to-the-screen-arkit-sw
As per the above link, upvoted answer by alex papa, the model gets placed in scene. But the model seems above ground hanging in air. The 3D object seems floating in air and not placed on detected/tapped horizontal plane using hit test.
The x & z position is right but y seems some meters above the horizontal plane.
I need scale to be 1.0. Without scaling down the 3D model is it possible to place / visualise it right?
Any help or leads will be of help. Please provide valuable inputs!
The scale of ARKit, SceneKit and RealityKit is meters. Hence, your model's size is 99m X 184m X 43m. Solution is simple – you need to take one 100th of the nominal scale:
let scaleFactor: Float = 0.01
node.scale = SCNVector3(scaleFactor, scaleFactor, scaleFactor)
And here you can read about positioning of pivot point.
Say my camera is rotated around the X axis 60 degrees and looking down on a 9x9 block chess board. As we adjust board size, I want to zoom out the camera. Say for arguments sake the camera's position is (4,20,-7) and like this the whole board is visible and taking up the full screen.
If I adjust my board size to say 11x11 blocks I will now need to zoom out the camera. Say I want to maintain the same 60 degree angle and want the board to fill as much of the screen as it did before. What should the camera's new position be and how do you calculate it?
The X part is easy since you simple give the camera the same X position as the middle of the board. I'm not sure about how to calculate the new Y and Z positions though.
Any advice appreciated. Thanks.
edit: and if i wanted to change the angle of the camera as well as zoom out, is that possible to calculate? this is less important since i'll probably stick with the same angle, but i'm interested to know the maths behind it anyway.
Transform.Translate() method will move the transform according to the rotation. So you don't have to worry about the direction where your camera is looking at, just
yourCamera.transform.Translate(Vector3.forward * moveAmount);
will move your camera forward, which means zoom in. If you want to zoom out, just change the sign of the value to minus.
When I didn't know this, I used Mathf.Sin() and Mathf.Cos() to calculate each y and z world coordinates, which sucks.
I am building an AR application. I have some points which are real worlds coordinates.
I can geolocate these points through Mapbox. My problem is that when I got far away from the points, they are looking getting smaller. I want to see them as the same size independently from the distance.
Here is an example of how to visualize the points:
So, if I near the points I see them in normal sizes. Even though I got 400 KMs away from the point, I want to see it in the same size. Is it possible?
You can try to scale the lables by some value * distance to object.
If you are standing in device and the target is in target it would be:
float experimentalScale = 0.5f
This is the amplifier of the distance. If you increase the value, the lable will get bigger by greater distance. Try out what works best for you.
float scaleFactor = Vector3.Distance(device.transform.position, target.transform.position) * experimentalScale;
target.transform.localScale(scaleFactor,scaleFactor,scaleFactor)
This only works if your Objects scale is 1. If it is something else, just multiply the scale with scaleFactor.
I would like to create a MKCoordinateRegion (to zoom to the good region on the map) from the northeast and southwest points given by Google. For that I need to compute the coordinate of the center between these two coordinates. Any clue? I could do simple math but I will have problems with the equator...
Thanks!!!
Assuming you mean anti-meridian and not the equator then here goes (While all this works on a flattened map and should be good enough for your purpose, it's completely bung on a sphere. see note at the bottom).
What I've done in other cases is start at either point, and if the next point is more than 180 degrees to the east, I convert it so that it is less than 180 to the west like so
if(pointa.lon - pointb.lon > 180)
pointb.lon += 360:
else if (pointa.lon - pointb.lon < -180)
pointb.lon -= 360
At this time pointb.lon might be an invalid longitude like 190 but you can at least work out the mid-point between pointa and point b because they will be on a continuous scale, so you might have points 175 and 190. Then just get the mid-point between them as 182.5, then convert that to make sure it is within the usual limits and you get -177.5 as the latitude between the two points. Working out the latitude is easy.
Of course on a sphere this is wrong because the midpoint between (-180,89) and (180,89) is (0*,90) not (0,89).
* = could be anything
Also, couldn't you just zoomToRect made with the defined corners? It'd save you doing this calculation and then next one which would be to work out what zoom level you need to be at when centered on that point to include the two corners you know about. Since the Maps app doesn't appear to scroll over the anti-meridian I assume MKMapview can't either so your rectangle is going to have to have the northeast coord as the top right and the southwest as the bottom left.
This SO post has the code to zoom a map view to fit all its annotations.
I'm using Core Motion and would like to count rotations, so if i place the iphone on the table and start to rotate it clockwise and do 360 degrees, i would get 1 rotation.
What should i use from Core Motion, yaw, roll, pitch, gravity, rotationMatrix or ?
Please help me.
Cheers.
You'd want to watch yaw — that's rotation around a notional line that would come straight upwards, out of the screen. It actually goes from +180 to -180, but for your purposes if you're rotating clockwise, screen upward, then you can just watch for the number to get higher instead of lower — that'll detect when the value goes beyond -180 and reappears somewhere below +180. Alternatively, look for any absolute change in value greater than, say, 180, if you want to be able to detect rotations clockwise or anticlockwise.