Using Cytoscape.js v2.1, I noticed something that maybe a bug (from this version or maybe mine =p).
When inserting a node, I'm using this to get node position from the tap event e:
position = {
x: e.cyPosition.x,
y: e.cyPosition.y
};
Also, my cytoscape initializer is setting layout fitas true:
$cy.cytoscape({
minZoom: 0.1,
maxZoom: 2.0,
layout: {
fit: true
},
(...)
And so the problems begin. Using this, on Windows 7, Chrome version 32.0.1700.107 or Firefox 27.0.1, the node is being positioned with a big offset (as shown here).
On the other hand, when I set layout fit as false, the node is correctly positioned. (as you can see in this link).
As it's happening only when initial zoom fit is true, I supose this is a specific bug of this option.
Please read the documentation regarding rendered versus model position. I think you've confused the two: http://cytoscape.github.io/cytoscape.js/#notation/position
Model position must stay constant despite pan and zoom. Otherwise, positions would be inconsistent.
On the other hand, rendered position is derived from the model position, pan, and zoom. Naturally, model position and rendered position differ when zoom differs from identity (1) or pan differs from the origin (0, 0).
It doesn't look like you're using rendered position for on-screen placement.
Edit:
Don't mix and match rendered position with model position. If you get model position in your handler (e.cyPosition), then continue to use model position to add nodes et cetera. If you get rendered position (e.cyRenderedPosition), then use rendered position to add nodes et cetera.
Mixing the two will never give desired behaviour unless you do some math to translate them.
Related
I want to place edge labels on a specified position in my graph. I found that i can manipulate the labels position with text-margin-x and text-margin-y but to calculate the needed margins I need to know the current position of the label. I already tried using source-label and the position of the source node but this means that text-events no longer work.
Is there a way to get/calculate the position of the label on segments edges?
Furthermore to help me align certain labels I need to know how to get/calculate the bounding box of the edge label, is there a way to do this?
Any help is appreciated!
I found that i can use edge.midpoint() to get the location of the label.
For the size of the label I use a workaround where I render everything once to get the labelHeight and labelWidth from rstyle and then I rerender everything correctly.
I want to find multiple objects in a scene (objects look the same, but may differ in scale, and rotation and I don´t know what the object to be detected will be). I have implemented the following idea, based on the featuredetectors in OpenCV, which works:
detect and compute keypoints from the object
for i < max_objects_todetect; i++
1. detect and compute keypoints from the whole scene
2. match scene and object keypoints with Flannmatcher
3. use findHomography/Ransac to compute the boundingbox of the first object (object which hast the most keypoints in the scene with multiple objects)
4. set the pixel in the scene, which are within the computed boundingbox to 0, -> in the next loopcycle there are no keypoints for this object to detect anymore.
The Problem with this implementation is that I need to compute the keypoints for the scene multiple times which needs alot of computing time (250ms). Does anyone has a better idea for detecting multiple objects?
Thanks Drian
Hello togehter I tried ORB which is indeed faster and I will try Akaze.
While testing ORB I have encouterd following problem:
While chaning the size of my picture doesn´t affect the detected keypoints in Surf (finds the same keypoints in the small and in the big picture (in the linked picture right)), it affects the keypoints detected by ORB. In the small picute i´m not able to find these keypoints. I tried to experiment with the ORB parameters but couldn´t make it work.
Picture: http://www.fotos-hochladen.net/view/bildermaf6d3zt.png
SURF:
cv::Ptr<cv::xfeatures2d::SURF> detector = cv::xfeatures2d::SURF::create(100);
ORB:
cv::Ptr<cv::ORB> detector = cv::ORB::create( 1500, 1.05f,16, 31, 0, 2, ORB::HARRIS_SCORE, 2, 10);
Do you know if, and how it´s possible to detect the same keypoints independent of the size of the pictures?
Greetings Drian
I have a node that I'm extracting from an SCNScene. I've got some information about it, but I'm confused about one thing - how the bounding box is calculated. The node is positioned once it is loaded at vector 0,0,0 using:
[myNode setPosition: SCNVector3Make(0, 0, 0)];
However, the bounding box still reports a min.x of -1.
How can this be if I've just positioned it at 0? Additionally, it doesn't matter what vector values I give, it always has a min.x of -1 - despite the node actually moving around screen as expected.
It's hard to answer definitively without more information about what's in your scene and what you're doing with it, but it's probably one or both of these issues:
The bounding box tells you the extent of the node's content, not its position — e.g. if you have a cube 2 units wide positioned at (0, 0, 0), its bounding box min and max corners will be (-1, -1, -1) and (1, 1, 1).
Depending on what tricks you're using to move your node around, the node itself may not be changing position — SCNActions, CAAnimations, and physics all work on a separate copy of the node hierarchy. (Partly this is to support implicit animation — e.g. set the position of a node, and it'll appear to animate from the current position to the position you set, but you can still read back position and have it be the value you set it to.)
You get to this separate hierarchy with the node's presentationNode property — ask the presentation node for its bounding box and you'll see its position/extent as affected by actions/animations/physics and currently rendered.
camera.rotate.y pans left or right in a predictable manner.
camera.rotate.x looks up or down predictably when camera.rotate.y is at 180 degrees.
but when I change the value of camera.rotate.y to some new value, and then I change the value of camera.rotate.x, the horizon rotates.
I've looked for an algorithm to adjust for horizon rotation after camera.rotate.x is changed, but haven't found it.
In three.js, an object's orientation can be specified by its Euler rotation vector object.rotation. The three components of the rotation vector represent the rotation in radians around the object's internal x-axis, y-axis, and z-axis respectively.
The order in which the rotations are performed is specified by object.rotation.order. The default order is "XYZ" -- rotation around the x-axis occurs first, then the y-axis, then the z-axis.
Rotations are performed with respect to the object's internal coordinate system -- not the world coordinate system. This is important. So, for example, after the x-rotation occurs, the object's y- and z- axes will generally no longer be aligned with the world axes. Rotations specified in this way are not unique.
So, for example, if in code you specify,
camera.rotation.y = y_radians; // Y first
camera.rotation.x = x_radians; // X second
camera.rotation.z = 0;
the rotations are applied in the object's rotation.order, not in the order you specified them.
In your case, you may find it more intuitive to set rotation.order to "YXZ", which is equivalent to "heading, pitch, and roll".
For more information about Euler angles, see the Wikipedia article. Three.js follows the Tait–Bryan convention, as explained in the article.
three.js r.61
I've been looking for the same info for few days now, the trick is: use regular rotateX to look up/down, but use rotateOnWorldAxis(new THREE.Vector3(0.0, 1.0, 0.0), angle) for horiz turn (https://discourse.threejs.org/t/vertical-camera-rotation/15334).
I have a UIView, which I'm drawing manually in the 'drawRect'-Function.
It is basically a coordinate system, which has 'Values' on the Y-Axis and 'Time' on the 'X-Axis'.
Due to space issues, I want the Timestamps to be vertical, instead of horizontal.
For this purpose, I use:
CGContextSaveGState(ctx); //Saves the current graphic context state
CGContextRotateCTM(ctx, M_PI_2); //Rotates the context by 90° clockwise
strPos = CGContextConvertPointToUserSpace(ctx, strPos); //SHOULD convert to Usercoordinates
[str drawAtPoint:strPos withFont:fnt]; //Draws the text to the rotated CTM
CGContextRestoreGState(ctx); //Restores the CTM to the previous state.
ctx (CGContextRef), strPos (CGPoint) and str (NSString) are variables, that have been initialized properly and correctly for 'horizontal text', with a width of the text height.
While this code works flawlessly on the iPhone 3, it gives me a complete mess on the iPhone 4 (Retina), because the CGContextConvertPointToUserSpace function produces completely different results, even though the coordinate system of the iPhone is supposed to remain the same.
I also tried using CGAffineTransform, but only with the same results.
To summarize my question: How do I draw a text to a calculated position in the parent coordinate system (0, 0 being top left)?
After studying the Apple docs regarding Quartz 2D once more, I came to realize, that the rotation by Pi/2 moves all my writing off screen to the left.
I can make the writing appear in a vertical line by translating the CTM by +height.
I'll keep trying, but would still be happy to get an answer.
Edit: Thanks to lawicko's heads-up I was able to fix the problem. See Answer for details.
I would like to thank lawicko for pointing this out.
During my tests I made two mistakes...but he is of course correct. Using CGContextShowTextAtPoint is the most simple solution, since it doesn't require the rotation of the entire CTM.
Again, THANK you.
Now, for the actual answer to my question.
To draw a rotated text at position x/y, the following code works for me.
CGAffineTransform rot = CGAffineTransformMakeRotation(M_PI_2); //Creates the rotation
CGContextSelectFont(ctx, "TrebuchetMS", 10, kCGEncodingMacRoman); //Selects the font
CGContextSetTextMatrix(ctx, CGAffineTransformScale(rot, 1, -1)); //Mirrors the rotated text, so it will be displayed correctly.
CGContextShowTextAtPoint(ctx, strPos.x, strPos.y, TS, 5); //Draws the text
ctx is the CGContext, strPos the desired position in the parent coordinate system, TS a char array.
Again, thank you lawicko.
I probably would've searched forever if not for your suggestion.
Maybe this answer will help someone else, who comes across the same problem.