Is there a way to constrain movement of vertices to a plane?
You can constrain it along an axis by pressing "x", "y", or "z". I want the z ordinate to remain stable while I move in the other two axis. I can always do a bit of "x" and a bit of "y", and more "x", and more "y", ... but as a newbie will forget and get myself messed up.
What I am trying to do is create a two-d shape on the x-y plane, that I will then use the solidify option to make 3D. For my work having "z" set to 0 is perfect.
Press g once then shift and z together to move along only x-y plane. Go into front orthographic view to verify object is only moving along x and y axis or look at the Z location.
Related
I have a data set “mydatainR”
With that I created a barplot and when I download the barplot, part of the y axis is cut off because it’s “off of the paper”
I want to give myself more room to work with, or make my entire bar plot smaller. Thx
Let's say I know two persons are standing at GPS location A and B. A is looking at B.
I would like to know B's (x, y, z) coordinates based on A, where the +y axis is the direction to B (since A is looking at B), +z is the vertically to the sky. (therefore +x is right-hand side of A)
I know how to convert a GPS coordinate to UTM, but in this case, a coordinate system rotation and translation seem needed. I am going to come up with a calculation, but before that, will there be some codes to look at?
I think this must be handled by many applications, but I could not find so far.
Convert booth points to 3D Cartesian
GPS suggest WGS84 so see How to convert a spherical velocity coordinates into cartesian
Construct transform matrix with your desired axises
see Understanding 4x4 homogenous transform matrices. So you need 3 perpendicular unit vectors. The Y is view direction so
Y = normalize(B-A);
one of the axises will be most likely up vector so you can use approximation
Z = normalize(A);
and as origin you can use point A directly. Now just exploit cross product to create X perpendicular to both and make also Y perpendicular to X and Z (so up stays up). For more info see Representing Points on a Circular Radar Math approach
Transfrom B to B' by that matrix
Again in the QA linked in #1 is how to do it. It is simple matrix/vector multiplication.
I am building an augmented reality application and I have the yaw, pitch, and roll for the camera. I want to start placing objects in the 3D environment. I want to make it so that when the user clicks, a 3D point pops up right where the camera is pointed (center of the 2D screen) and when the user moves, the point moves accordingly in 3D space. The camera does not change position, only orientation. Is there a proper way to recover the 3D location of this point? We can assume that all points are equidistant from the camera location.
I am able to accomplish this independently for two axes (OpenGL default orientation). This works for changes in the vertical axis:
x = -sin(pitch)
y = cos(pitch)
z = 0
This also works for changes in the horizontal axis:
x = 0
y = -sin(yaw)
z = cos(yaw)
I was thinking that I should just make combine into:
x = -sin(pitch)
y = sin(yaw) * cos(pitch)
z = cos(yaw)
and that seems to be close, but not exactly correct. Any suggestions would be greatly appreciated!
It sounds like you just want to convert from a rotation vector (pitch,yaw,roll) to a rotation matrix. The conversion can bee seen on the Wikipedia article on rotation matrices. The idea is that once you have constructed your matrix, to transform any point simply.
final_pos = rot_mat*initial_pose
where final and initial pose are 3x1 vectors and rot_mat is a 3x3 matrix.
I'm creating simple game and reached the point where I feel helpless. I was good in geometry but it was long time back in school, now trying to refresh my mind.
Let's say i have iPad screen. Object's xy position at one given point of time and xy position at another point of time stored in 2 variables .
Question:
how to find the third position of the object at the end of the screen being given previous 2 position, considering the object moves in the same direction (line) from point 1 to point 2.
Thanks in advance.
Let us have that v1 and v2 are the vectors representing the two points. Let t0 be the time between the two points. Let t be the current time.
Then our location vector v3 is given by v3 = v1 + (v2 - v1)t/t0
If the object is moving in the same direction and you have an horizontal line, the next position given x and y would be
x+1, y
If the object is moving in the same direction in a vertical line it would be
x, y+1
If the object is moving in a diagonal up-right
x+1,y+1
diagonal down-right
x+1, y+1
diagonal down-left
x-1, y-1
diagonal up-left
x-1, y+1
So something general would be :
newPosition = (x+1,y) //if you wish to move forward to the right, try to handle all
cases
All the cases above work if the object is moving forward, if it is moving backwards just change the + by - . Basically think of the object as moving in a cartesian coordinate system, where x is horizontal and y is vertical.
I think you can get the idea out of this three cases ;)
I've been having a bit of a problem with making the Y axis my up axis when exporting mesh and scenes from Blender. Both Blender and my export target use right handed transformation matrices. Z is the up axis in Blender while Y is the up axis in my target. The problem exists in 2 places though. The scene's transformations can't just be shifted on the X axis to fix this, because I also need to do the Y/Z switch for the vertices in the mesh (export as vertex.x, vertex.z, vertex.y). I need to have the actual Y and Z rotations switched, so that if the Y and Z rotations are the same, no change will occur (ie. identity). Thanks for your help in advance. Feel free to ask questions if I was not thorough enough.
Blender does two things different than the rest of the known world!
1. It uses Z axis for vertical (should be Y); Y axis for horizontal (should b X); and X axis for in and out (should b Z).
Very weird! Every high school graph since the beginning of time uses X for horizontal and Y for vertical.
It uses the right mouse button for selections.
U can change the selection btn in Preferences, but not the crazy axis arrangement!
no,
you do this
y=z
z=-y
no rotation of 90 degrees can make you go from left to right hand.
I ran into a similar issue when working with cinema4d and blender. In cinema4d Y is the up axis and rotations are heading,pitch and bank.
Blender's system looks like a right handed system, but rotated by 90 degrees on x axis.
I did the same thing for coordinates(exported as vertex.x,vertex.z,vertex.y). For rotations,
I think you should add 90 degrees(math.pi * 0.5) for rotations on X axis and the rest should be fine.
HTH
Have you tried just using Select All (the 'a' key) and then r x 90 to rotate everything 90 degrees around the X axis and the pivot point? (your pivot point is choosable in the menu bar of the 3D view if you need to control that).
You could do that, export, and then undo.
Just Download Wings3D. Export from Blender as .3ds and then Import this file in Wings3D.
Now you can just export it from Wings3D, again to .3ds. But instead of clicking directly on .3ds, click on the small icon in the right of the ".3ds" menu. now you can unchecked the Box Swap y und z axis and import the .3ds in another program.
There is no way that would be possible. Coordinate system was innately selected as hard coded from the blender source and there are no explicit option has been made in blender to switch it. It would also affected many of the hard coded functionality of any function blender was used or has been made by assume that coordinate
However, in theory, it would be possible to access blender source code and rebuild the blender to have it use another coordinate we would like. Albeit we need to carefully swap everything related to coordinate system
I too wish that left handed coordinate system (as of Unity3D) would be industrial standard and blender should at least have another version that work in left handed coordinate. People should just graduated from table coordinate to screen coordinate already
In blender, you could add empty plain axes, that will correct your orientation when exporting to unity, or try exporting as fbx file and change orientation in export options