I am creating a 3d text on blender2.8 but I am having a hard time trying to make it appear on the camera view.
I have tried rotating and scaling the camera but it doesn't help.
The camera object is the focal point for the final image, like in real life, if you want to get more in the picture you need to move the camera back or zoom out.
With the camera close -
With the camera far away -
To zoom out, you reduce the camera's focal length.
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TLDR: I want to rotate camera but render sprites in regards to their world position not camera position.
Howdy,
I'm currently using LibGDX and have come across an issue in regards to camera/object rotation.
Say I have my camera with a rotation of 0 and I have an object(sprite) to the left of the camera's center.
i.e.
Camera Normal (0 degrees rotation)
The sprite renders fine when given a standard world coordinate, however once I rotate my camera, that world coordinate differs from the camera's new (x, y) values.
If I then rotate my camera smoothly 90 degrees to the right(clockwise so that the up direction is facing to the right like the picture below), the object(sprite) that used to be on the left should have simulated a left rotation in regards to the camera (the rotation happens via the camera, the sprite just needs to update position) and now be below the camera's center point.
i.e.
Camera Rotated (90 degrees clockwise)
I'm confused as to how I would calculate the sprite's new locations/positions during the smooth rotation.
Cheers,
Solist.
After looking everywhere for a solution to this problem for 3 weeks it was merely a matter of me needing to call the method
batch.setProjectionMatrix(camera.combined);
in order to update the sprites to their new position in regards to the changing camera rotation.
This link here explains how the Projection Matrix works.
I am using Three.JS to create a scene.
I want to be able to set my camera in the corner of a room and have the viewer rotate the camera around on the spot, without moving the camera's position.
Also, I want to limit the span of rotation (so that they cannot rotate the camera to look behind them).
I found FirstPersonControls, but I want the user to have to click and drag to rotate the view.
I know of the minecraft example, but it doesn't do the click and drag or angle restriction.
Does anyone know of any other existing examples that accomplish something similar? Thanks.
I have a robot and a camera. The robot is just a 3D printer where I changed the extruder for a tool, so it doesn't print but it moves every axis independently. The bed is transparent, and below the bed there is a camera, the camera never moves. It is just a normal webcam (playstation eye).
I want to calibrate the robot and the camera, so that when I click on a pixel on a image provided by the camera, the robot will go there. I know I can measure the translation and the rotation between the two frames, but that will probably return lots of errors.
So that's my question, how can I relate the camera and a robot. The camera is already calibrated using chessboards.
In order to make everything easier, the Z-axis can be ignored. So the calibration will be over X and Y.
It depends of what error is acceptable for you.
We have similar setup where we have camera which looks at some plane with object on it that can be moved.
We assume that the image and plane are parallel.
First lets calculate the rotation. Put the tool in such position that you see it on the center of the image, move it on one axis select the point on the image that is corresponding to tool position.
Those two points will give you a vector in the image coordinate system.
The angle between this vector and original image axis will give the rotation.
The scale may be calculated in the similar way, knowing the vector length (in pixels) and the distance between the tool positions(in mm or cm) will give you the scale factor between the image and real world axis.
If this method won't provide enough accuracy you may calibrate the camera for distortion and relative position to the plane using computer vision techniques. Which is more complicated.
See the following links
http://opencv.willowgarage.com/documentation/camera_calibration_and_3d_reconstruction.html
http://dasl.mem.drexel.edu/~noahKuntz/openCVTut10.html
I am writing a Cocoa application for mac osx. I'm trying to figure out how to determine the size of an image that will be captured by a camera? I would like to know the size of the image that will be captured so I can setup a view with an aspect ratio that won't distort the image. For example, if my view is defined to be 640x360 and my camera captures images that are 640x480, the displayed image looks short and fat. I'm also displaying some other layers over the image and I need the image size to be able to scale and position the layers properly.
I won't know the type of camera that is attached until run-time so I'd like to be able to interrogate the device and get attributes like image size. Thanks for the help...
You are altering the aspect ratio of the image when you capture in 640x360 instead of 640x480 or 320x240. You are doing something similar as a resize, using the whole image and making it a different size.
If you don't want to distort the image, but use only a portion of it you need to do a crop. Some hardware support cropping, others don't and you have to do it in software. Cropping is using only portions of the original image. In your case, you would discard the bottom 120 lines.
Example (from here):
The blue rectangle is the natural, or original image and the red is a crop of it.
I wonder if someone could tell me how to make it possible to move a camera in a 3D space when
the camera is rotated.
I am working on my own 3D engine (nothing fancy) and I can move the camera forward backward left right up down, thats all good.
However when I rotate the camera, it doesnt move in the direction that the camera is directed to.
Here is a picture that should help you understand what I mean:
http://www.xaid.se/camrot.jpg
Does anybody know how to make this work?
(If you're interested in what I'm working on, visit this site)
i'm not sure if i really get what you mean, but your problem looks like you want to move along the direction of the camera instead along one (main-)axis?
therefore my solution would be to store a vector which keeps the direction the camera is looking, and update this vector everytime you rotate the camera. now you can use your direction vector for the forward movement. position + vector*stepsize.
hope that helps a little bit.