How to have multiple cameras in a manim 3D Scene - manim

I'm looking for a setup in manim (0.8.0 CE) where I have in the main part of the screen an ambiente camera plus two addtional views on the right hand side (like a picture in picture, or split screen) from a fixed diffrent angle on the scene. I've found a MultiCamera Class, but this is fixed to a MovingCamera. I assume that I need additional three_d_camera objects, but couldn't find any example in any of the tutorials which points me in the right direction. Are there any ideas how to do this?

Related

Draw lines via spriteKit with coordinates and ability to change it

I need create two screens: one shows created vectors (lines) and other change parameters of them (coordinates, size). I should use SpriteKit for this.
But I don't now how to draw this lines buy swipe on screen and make this lines straight as vectors.
Plese, help

Getting the current visible entities in RealityKit

Currently, RealityKit doesn't have any method that provides the currently visible entities. In SceneKit we do have a method for that particular functionality—nodesInsideFrustum(pointOfView).
Our internal solution is to create a big fake bounding box in front of the camera. We then check intersections between the "frustum" bounding box and each entity's bounding box. That, of course, is a bit cumbersome and inaccurate. I wonder if someone can come up with a better solution who is willing to share it.
You could combine two ARView methods:
ARView.project(position) to get the 2D point in screen space
ARView.bounds.contains(point) to know if it's visible on screen
But it's not enough, you also have to check if the object is behind you:
Entity.position(relativeTo: cameraAnchor) (with cameraAnchor being an AnchorEntity(.camera)) to have the local position
the sign of localPosition.z shows if it's in front or behind the camera

ARKit: How to detect only Horizontal floor excluding obstacles

I am developing horizontal plane detection application using ARKit. It seems to be working fine. Once floor is detected I am trying to place SCNPlane 2meter Hight and 2meter width horizontally from the centre point(detected floor). It is also working fine when floor is empty. If floor has some objects(obstacles like furniture) then SCNPlane is being placed over the object instead of the floor(under the object). How to detect only Horizontal floor excluding the objects. please guide me. thanks
When you are searching and have found the floor the ARKit will put out a grid, normally people use some kind of grid image to display this, but some don't want to show it. Once the grid has placed you place a SCNPlane, which i assume has an physical body as you say it falls towards the floor / furniture?
You can do this in 3 ways:
You can to stop the worldTrackingConfiguration once the floor has
been found.
You can once the floor has been found, fetch that Y-position and bind every object to fall towards that Y-position.
I guess you could check if the Y-position of the new detection overlaps with the floor detection, then it's fine else it's not. (I have not tested this one)

Interact with complex figure in iOS

I need to be able to interact with a representation of a cilinder that has many different parts in it. When the users taps over on of the small rectangles, I need to display a popover related to the specific piece (form).
The next image demonstrates a realistic 3d approach. But, I repeat, I need to solve the problem, the 3d is NOT required (would be really cool though). A representation that complies the functional needs will suffice.
The info about the parts to make the drawing comes from an API (size, position, etc)
I dont need it to be realistic really. The simplest aproximation would be to show a cilinder in a 2d representation, like a rectangle made out of interactable small rectangles.
So, as I mentioned, I think there are (as I see it) two opposite approaches: Realistic or Simplified
Is there a way to achieve a nice solution in the middle? What libraries, components, frameworks that I should look into?
My research has led me to SceneKit, but I still dont know if I will be able to interact with it. Interaction is a very important part as I need to display a popover when the user taps on any small rectangle over the cylinder.
Thanks
You don't need any special frameworks to achieve an interaction like this. This effect can be achieved with standard UIKit and UIView and a little trigonometry. You can actually draw exactly your example image using 2D math and drawing. My answer is not an exact formula but involves thinking about how the shapes are defined and break the problem down into manageable steps.
A cylinder can be defined by two offset circles representing the end pieces, connected at their radii. I will use an orthographic projection meaning the cylinder doesn't appear smaller as the depth extends into the background (but you could adapt to perspective if needed). You could draw this with CoreGraphics in a UIView drawRect.
A square slice represents an angle piece of the circle, offset by an amount smaller than the length of the cylinder, but in the same direction, as in the following diagram (sorry for imprecise drawing).
This square slice you are interested in is the area outlined in solid red, outside the radius of the first circle, and inside the radius of the imaginary second circle (which is just offset from the first circle by whatever length you want the slice).
To draw this area you simply need to draw a path of the outline of each arc and connect the endpoints.
To check if a touch is inside one of these square slices:
Check if the touch point is between angle a from the origin at a.
Check if the touch point is outside the radius of the inside circle.
Check if the touch point is inside the radius of the outside circle. (Note what this means if the circles are more than a radius apart.)
To find a point to display the popover you could average the end points on the slice or find the middle angle between the two edges and offset by half the distance.
Theoretically, doing this in Scene Kit with either SpriteKit or UIKit Popovers is ideal.
However Scene Kit (and Sprite Kit) seem to be in a state of flux wherein nobody from Apple is communicating with users about the raft of issues folks are currently having with both. From relatively stable and performant Sprite Kit in iOS 8.4 to a lot of lost performance in iOS 9 seems common. Scene Kit simply doesn't seem finished, and the documentation and community are both nearly non-existent as a result.
That being said... the theory is this:
Material IDs are what's used in traditional 3D apps to define areas of an object that have different materials. Somehow these Material IDs are called "elements" in SceneKit. I haven't been able to find much more about this.
It should be possible to detect the "element" that's underneath a touch on an object, and respond accordingly. You should even be able to change the state/nature of the material on that element to indicate it's the currently selected.
When wanting a smooth, well rounded cylinder as per your example, start with a cylinder that's made of only enough segments to describe/define the material IDs you need for your "rectangular" sections to be touched.
Later you can add a smoothing operation to the cylinder to make it round, and all the extra smoothing geometry in each quadrant of unique material ID should be responsive, regardless of how you add this extra detail to smooth the presentation of the cylinder.
Idea for the "Simplified" version:
if this representation is okey, you can use a UICollectionView.
Each cell can have a defined size thanks to
collectionView:layout:sizeForItemAtIndexPath:
Then each cell of the collection could be a small rectangle representing a
touchable part of the cylinder.
and using
collectionView:(UICollectionView *)collectionView
didSelectItemAtIndexPath:(NSIndexPath *)indexPath
To get the touch.
This will help you to display the popover at the right place:
CGRect rect = [collectionView layoutAttributesForItemAtIndexPath:indexPath].frame;
Finally, you can choose the appropriate popover (if the app has to work on iPhone) here:
https://www.cocoacontrols.com/search?q=popover
Not perfect, but i think this is efficient!
Yes, SceneKit.
When user perform a touch event, that mean you knew the 2D coordinate on screen, so your only decision is to popover a view or not, even a 3D model is not exist.
First, we can logically split the requirement into two pieces, determine the touching segment, showing right "color" in each segment.
I think the use of 3D model is to determine which piece of data to show in your case if I don't get you wrong. In that case, the SCNView's hit test method will do most of work for you. What you should do is to perform a hit test, take out the hit node and the hit's local 3D coordinate of this node, you can then calculate which segment is hit by this touch and do the decision.
Now how to draw the surface of the cylinder would be the only left question, right? There are various ways to do, for example simply paint each image you need and programmatically and attach it to the cylinder's material or have your image files on disk and use as material for the cylinder ...
I think the problem would be basically solved.

Moving around the planet in sprite kit

I'm currently making a game where driving a moon lander across the terrain of alien planets. The lander is free moving so you can turn any direction you like.
I've got a camera centred on the player's vehicle and navigation is working well, however...
As the player approaches the horisontal sides (x) of the map I'd like the map to display continuously.
I've used a couple of different approaches so far; I've added an identical sprite as the map to the left of the map and created a method that moves the extended map to the right side if you approach that side instead, and I've also tested with two different extended maps, one for left and one for right. I've then setup physics for the extended maps and changed the landers position from one side of the map to the other as it collides with the extended maps.
My issue is that I'd like to have my enemies spawning and walking around the main map and as you approach the side you will of course not see the enemies on the other side of the map - you'd only see the extended map with no contents.
My preference would be for the world to "bend" so that as you approach the left edge you'd automatically see the right edge and vice versa. I have no idea whether this is even feasible so any suggestions are much appreciated.
Thanks in advance.
I'm not sure I understand your question. Maybe this will further discussion, anyhow.
If you are looking for a scrolling behavior then I would have two backgrounds (or more if you want a wider scrolling field) and your method for swapping the tiles around to make the background feel continuous, use the "camera" tracking technique and shown in Apple's sprite kit demo to follow your player (which it sounds like you are doing). Then when aliens move offscreen in either direction relocate them in the same way that you would swap out your background tile(s) with something like position.x += widthOfBackgroundTile.

Resources