Unity - possible to have bending grass? Mesh? - c#

Ok here is what Im trying to achieve - when user's feet collide with grass mesh, the mesh is secured to the ground at the base but the tops move away, then bounce back when foot is no longer there:
This example, and everything I've found however, are using billboarding/2d as grass. I want 3d, like these:
https://assetstore.unity.com/packages/3d/vegetation/plants/grass-toon-76674
Where some sort of collision is occurring, or Ive tried experimenting with unity's trees. Trying to find the most CPU/GPU effective (for Oculus app or mobile) way to do this.
Is this possible - to have interactive, 3d not 2d grass?

The only thing I can think of is to model each blade of grass as several bars connected by universal joints (I'm not sure what kind they would be in unity, but that is the mechanisms term).
Each joint could have a torque proportional to its angle, so the more you bend it, the harder it tries to flick back. Then its just a matter of adding forces to the blade structures as you bump into them.
This is more of a engineering solution than a programming one, and would require a little bit of math, so its probably not ideal. but it should work.

Related

How do I make dynamic 2D collisions faster in unity?

Currently I'm working on a 2D game with destructible terrain in unity. It works great! Except for one thing.... collision generation... Since the terrain is destructible, I have to generate collisions on the go. I tried and it's awful performance. From 1000 fps from editing the terrain to 1 fps when I enable collisions generation. This is a huge issue and I know it's possible within unity because this guy :
https://forum.unity.com/threads/wip-nimbatus.221798/
created it with collisions as well. I tried contacting him but no response yet! Any of you guys have any ides on what I can do? Thanks!
I found a rather annoying but working solution to the issue. So basically what was wrong was I was setting points as vertices. The guy I messaged told me that at the time when he made his game, the 2D engine wasn't a thing in unity so he was forced to use regular 3D components. I didn't want to do this because it would possibly limit what I can do with 2D packages since I am not using the 2D engine. But in the end I decided that unless I could find a extremely fast edge finding algorithm that supported concave meshes WITH holes, I would need to just use the regular Unity3D MeshCollider component. I'm not sure why I was having an issue with the Polygon collider as I thought it would work the same as the MeshCollider but in 2D. I think the issue was I was setting the path of the Polygon Collider as each vertice. This is wrong because I think I would need to set the edge vertices only. (My mesh does not share vertices so I'm not sure how to find the edges) Of course I could re write it to share vertices but I think I will be find with the 3D components (For now at least)

AR objects drift issue in Google TANGO

I am trying to create a simple scene where a few objects are placed on the table. Object placement works perfect but when I move the device, the objects drift around a bit. Which at one point makes the objects placed at the corner feel like they are not on the table but floating in the air.
Even in the sun moon and earth example in Unity examples here: https://github.com/googlesamples/tango-examples-unity
The earth n moon drifts as you move the device
Is this a bug or is there any special setting which I'm missing?
The objects drift because as the Tango device moves through space, it is only tracking its own position in 3D space. For objects to remain static in a dynamic environment, the device needs to understand the position of the placed objects in 3D space and their relation to the surroundings in order to anchor the objects and reduce drift.
Luckily, TangoCore has you covered here and the 3 Core technologies of Motion Tracking, Depth Perception and Area Learning all work together to help out.
If I'm not mistaken, the Sun and Moon example is the scene "SimpleAugmentedReality" under tango-examples-unity / UnityExamples / Assets / TangoSDK / Examples / Scenes /
However if you would like to anchor the objects in 3D space and reduce drift, you'll need to use Area Learning and Depth Perception as well. Area learning performs Loop Closures as the device realises it has "seen" an area before and adjusts the path and markers to provide a more accurate device and augmented content position.
So here is what you can do to learn what you need to. Save your current scene, go to open Scene and follow this path tango-examples-unity / UnityExamples / Assets / TangoSDK / Examples / Scenes / and load up some of the other scenes to get an understanding of how the technologies intertwine.
For example, you could load up the ExperimentalMeshBuilderWithColour scene, and learn how the Depth Processing works programmatically, and then load the MotionTracking scene and learn how to access and use Motion Tracking from the TangoManager Game Object. And finally (also probably most frustratingly difficult) learn how Area Learning is managed with the AreaDescriptionManagement and AreaLearning scenes.
This will not only solve your drift issues, but also give you a much fuller understanding of the capabilities of the Tango Technology and allow you to express your ideas much easier.

Leap Motion Coordinate System, Translations and Interaction Box with Unity C#

I am working on a Unity leap motion desktop project using latest versions of Orion and unity prefabs package. I have created a simple scene pretty much identical to the one in Desktop Demo scene. (pair of capsule hands and a simple object you can poke and move around)
https://developer.leapmotion.com/documentation/csharp/devguide/Leap_Coordinate_Mapping.html
This article covers all of the issues I am currently facing but so far, I was unable to implement these solutions in my project.
When moving hands from the maximum range of the camera for example left to right or any other direction, this only translates to a portion of available screen space, in other words, a user will never be able to reach out to the edges of a screen with their hands. From my understanding, the tracking info provided in millimetres by the camera is somehow translated into units that Unity can understand and process. I want to change that scale.
From the article, "You also have to decide how to scale the Leap Motion coordinates to suit your application (i.e. how many pixels per millimetre in a 2D application). The greater the scale factor, the more affect a small physical movement will have." - This is exactly what I want to do in Unity.
Additionally, even being able to what I think was a successful attempt at normalisation of coordinates using the InteractionBox, I am unsure what to do with the results. How or rather, where do I pass these values so that it will display the hands in an updated position.

Silverlight Collision Detection when controls are in different canvasses/layers

For our game we have to create collision detection.
The problem is that the collided objects are in different canvasses/layers, which makes collision detection by pointlocation inpossible.
Does anyone have an idea how to solve this?
It's hard to give a great answer without some more information, but if all your layers are the same size then you can just roll your own collision detection. All you need to know is the locations and sizes of two things to be collision detected. Then you just test to see if one rectangle intersects with the other rectangle.
There is also a function that might be useful to use called TranslatePoint. This translates from one UIElements coordinates to another. So if you had a ball bouncing around in a smaller area of the screen with it's own local coordinate system, you could get the ball's coordinates relative to the entire screen with this function.
Can I suggest you try using the Farseer physics engine just to save yourself some pain?
http://farseerphysics.codeplex.com/
It's very good and is in use in some WP7 games already.
http://www.farseergames.com/
There's also some Blend behaviors and helpers to make using it even easier:
http://physicshelper.codeplex.com/

C# Mobile Game Development

I'm currently trying to implement a marble maze game for a WM 5.0 device and have been struggling with developing a working prototype. The prototype would need the user to control the ball using the directional keys and display realistic acceleration and friction.
I was wondering if anyone has experience with this and can give me some advice or point me in the right direction of what is essential and the best way to go around doing such a thing.
Thanks in advance.
Frank.
When reading your answer I didn't get the feeling you are looking for a game framework, but more: how can I easily model a ball with acceleration and friction.
For this you don't need a full fledged physics framework since it is relatively simple to do:
First create a timer which fires 30 times a second, and in the timer callback do the following:
Draw the maze background
Draw a ball at ballX, ballY (both floating point variables)
Add ballSpdX to ballX and add ballSpdY to ballY (the speed)
Now check the keys...
if the directional key is left, then subtract a small amount of ballSpdX
if the directional key is topleft, then subtract a small amount of ballSpdX and ballSpdY
etc
For collision do the following:
first move the ball in the horizontal direction. Then check the collisions with the walls. If a collision has been detected, then move the ball back to its previous positions and reverse the speed: ballSpdX = -ballSpdX
move the ball in the vertical direction. Then check the collisions with the walls. If a collision has been detected, then move the ball back to its previous positions and reverse the speed: ballSpdY = -ballSpdY
by handling the vertical and horizontal movement separately, the collision is much easier since you know which side the ball needs to bounce to.
last nu not least friction, friction is just doing this every frame: ballSpdX *= friction;
Where friction is something like 0.99. This makes sure the speed of the ball get's smaller every frame due to friction;
Hope this helped
I would recommend checking out XNA Studio 3, it has built in support for PC, Xbox 360 and mobile devices, and it's an official & free spin-off of Visual Studio from Microsoft.
http://creators.xna.com/en-US/
http://blogs.msdn.com/xna/
If you search around, people have written tutorials using physics (velocity on this one)
http://www.xnamachine.com/2007/12/fun-with-very-basic-physics.html
Try XFlib. It is in c++, but most cool things for the mobile have to be in c++, unfortunately. The site has some very cool free games. You can also see the source of most of the game too. Many have the physics you want.
Unfortunately, XNA doesn't support the windows mobile platform. However, as it seems that you're not having a problem with the technical issue of drawing on the WM device, but with the logic required to implement physics based movement, then it's not a bad idea to consider XNA to prototype the physics and movement code.
Check out some of the educational topics at creators.xna.com, and also "gamedev.net"
If you are at a loss, there's no mistake in trying a "lighter" tool for prototype. I would try Torque Game Builder - it spits out XNA, although maybe not meant for your platform.
At the Samples of the Windows Mobile SDK (check out the WM 6.0 SDK too), there are a couple of game applications. One of them is a simple puzzle game; not much, but it is a starting point.
The use of physics in game development is not specific for Windows Mobile. You can find a huge literature about this subject. This comes up in my mind now. If you are serious about game development, in any platform, you should do a little research first.
I dont know if this may help but i saw a Marble application for the Android platform on google code. Check it out here, it may throw some insight on the actual logic of the game.
The code is open sourced and written in java (using the android sdk) put nevertheless it may be useful. Also to better understand the code checkout the documentation for the SensorsManager, SensorEvent etc here
I wouldn't recommend using the same architecture as this application thou.

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