I have a turn on spot animation that actually turns the player 61 degrees in maya. But when import the animation to unity and apply it to a animator controller to control a character, it turns the character 56 degrees. Why the turn angles are different?
Maya and some other 3D packages export their models with Z-axis faces upward. Standard scripts in Unity assume the Y-axis represents up in your world axis. It is better to fix the rotation in Unity than to modify the scripts to make things fit.
How do I fix the rotation of an imported model?
The same problem refers to orientation in Unity:
Rotation and Orientation in Unity
See also Euler vs Quaternion and The order of transformation in Maya.
Related
I am trying to create a 3D Visualization of an RC airplane in Threebox. The RC plane sends live telemetry, including:
GPS Coordinates
Gyro sensor data, showing the pitch, roll and heading of the plane.
I have now loaded a Model of an airplane in Threebox, no problems with that.
My problem comes down to the rotation of the plane. I want the plane object to represent the current orientation of the RC plane. Since I have the live telemetry from the flight controller, this should be possible.
In the Documentation, I have found this method, which seemed like exactly what i needed:
plane.setRotation({x: roll, y: pitch, z: yaw/heading})
And it basically works. I can rotate the Plane around its axes. But things get messed up when I combine the rotations.
For example: When I just update the roll axis, the Object behaves just like I want it to. However, when i change the heading of the plane by 90 degrees, the roll axis suddenly becomes the pitch axis. It seems to me, that the axes of the Plane object don't rotate with the plane itself.
I've prepared a recreation of the issue on jsfiddle. You can change the heading of the plane using the slider in the bottom right.
I've been stuck on this for days, would be super happy for any help!
There are lots of issues with your jsfiddle that prevent it from running. To isolate an issue and make it easier to test you should eliminate as many variables as possible - you're using two third-party libraries that will play a big hand in how transformations behave, particularly threebox.
I would recommend sticking with three.js's built in transformation tools unless you specifically need some lat/lng transformations, or other transformations to move between a local cartesian space and a global coordinate system. In this case, a very basic plane.setRotationFromEuler(new THREE.Euler(yaw, pitch, roll)) should do the trick. Be aware of how much order in euler rotations can affect the outcome, and that three.js uses radians for all its rotations, not degrees.
I'm working on a project where I'm putting a 3d cylinder object in front of a static 2d image on a three.js canvas, trying to make the cylinder look like its part of the photo.
In order for the 3d cylinder's perspective to match the photo behind it, it needs to be moved down the y axis. The problem is then it's moved out of the scene. I need a way to render the 3d cylinder how it would look with a -y position, but not actually move down the scene.
See image for details:
A combination of x-axis rotation to around 24 degrees, Lowering the FOV to around 10, and increasing the camera.position.z to about 35 got me the results I needed. Thank you #prisoner849
I have a 2D plane with a tree texture that always faces the general direction of the camera by rotating only on its Y axis. It works great and the shadows are cast perfectly, but I don't want the shadow of the 2D plane to rotate with it.
I'd like the shadow to appear so that the 2D object is always facing directly at a light source even when its not. I've tried messing with shaders without any luck. Should I be investigating shader tricks with this, or is there already something available from within Three.js that can do this already?
I was thinking it's that or come up with an invisible plane at the same position of the other 2D plane, and force it to face the light source and cast shadows, but that would cause other complications.
The reason for needing this is to keep thick, bushy shadows for 2D trees in a scene.
I managed to get rotations on the console in blender, but when I try to apply it in Unity, it is just very wrong. I am using Quaternion.Set
to set the desired rotation. I know that blender uses (WXYZ) quaternion, but when I got these values and set properly it in to Unity3D (XYZW), it gives me nonsense rotations.
http://pastebin.com/bKzUVCih
here is the link to my script. Please help me point out what is wrong there.
P.S.: Euler rotations are not an option, because they're lossy as far as I know...
I have solved this problem to my satisfaction. The problem is that the XYZ rotations of Unity are different from those of Blender. If you wish to convert positioning and rotation of an object perfectly from Blender to Unity, use the following steps:
Rotate the object -90 degrees on the X axis.
Calculate the Blender quaternion. Remember that the Blender quaternion is going to come out in a WXYZ matrix, and a Unity quaternion is going to use a XYZW order.
Rotate your object back 90 degrees on the X axis, export to FBX using the experimental, "apply transform," check box.
Translate your object in Unity using the translation in Blender, BUT use the equivalent of (-X, Z, -Y) for your translation.
If you're looking for a Python script to get the quaternion out of Blender, I've put together one and put most of it here
I might as well put a YouTube clip together on this, it's simplistic but ridiculously hard to figure out.
Context: trying to take THREE.js and use it to display conic sections.
Method: creating a mesh of vertices and then connect face4's to all of them. Used two faces to produce a front and back side so that when the conic section rotates it won't matter from which angle the camera views it.
Problems encountered: 1. Trying to find a good way to create a intuitive mouse rotation scheme. If you think in spherical coordinates, then it feels like just making up/down change phi and left/right change phi would work. But that requires that you can move the camera. As far as I can tell, there is no way to change actively change the rotation of anything besides the objects. Does anyone know how to change the rotation of the camera or scene? 2. Is there a way to graph functions that is better than creating a mesh? If the mesh has many points then it is too slow, and if the mesh has few points then you cannot easily make out the shape of the conic sections.
Any sort of help would be most excellent.
I'm still starting to learn Three.js, so I'm not sure about the second part of your question.
For the first part, to change the camera, there is a very good way, which could also include zooming and moving the scene: the trackball camera.
For the exact code and how to use it, you can view:
https://github.com/mrdoob/three.js/blob/master/examples/webgl_trackballcamera_earth.html
At the botton of this page (http://mrdoob.com/122/Threejs) you can see the example in action (the globe in the third row from the bottom).
There is an orbit control script for the three.js camera.
I'm not sure if I understand the rotation bit. You do want to rotate an object, but you are correct, the rotation is relative.
When you rotate or move your camera, a matrix is calculated for that position/rotation, and it does indeed rotate the scene while keeping the camera static.
This is irrelevant though, because you work in model/world space, and you position your camera in it, the engine takes care of the rotations under the hood.
What you probably want is to set up an object, hook up your rotation with spherical coordinates, and link your camera as a child to this object. The translation along the cameras Z axis relative to the object should mimic your dolly (zoom is FOV change).
You can rotate the camera by changing its position. See the code I pasted here: https://gamedev.stackexchange.com/questions/79219/three-js-camera-turning-leftside-right
As others are saying OrbitControls.js is an intuitive way for users to manage the camera.
I tackled many of the same issues when building formulatoy.net. I used Morphing Geometries since I found mapping 3d math functions to a UV surface to require v little code and it allowed an easy way to implement different coordinate systems (Cartesian, spherical, cylindrical).
You could use particles instead of a mesh I suppose but a mesh seems best. The lattice material is not too useful if you're trying to understand a surface mathematically. At this point I'm thinking of drawing my own X,Y lines on the surface (or phi, theta lines etc) to better demonstrate cross-sections.
Hope that helps.
You can use trackball controls by which you can zoom in and out of an object,rotate the object,pan it.In trackball controls you are moving the camera around the object.Object still rotates with respect to the screen or renderer centre (0,0,0).