I'm using this to control the color scale on a fractal drawing program. I was wondering if there was a way to eliminate the r,g,b variable and insert the result right into the img ndarray? I have fiddled with adding a new dimension with np.expand_dims, but the shape turns into (5,5,1) instead of (5,5,3) like I need. reshaping it seems to be a nightmare.
import numpy as np
#img is an array of values to be converted into RGB from another process
img = np.arange(25)
img = np.reshape(img,(5,5))
#simplified example of original process
r = img*2
g = img*3
b = img*4
#creating new array to accomidate the higher dimension
img = np.array([r,g,b], dtype = np.uint8)
#no longer needed
del r,g,b
#rolling axis for PIL Image.fromarray compatibily
img = np.rollaxis(img,0,3)
img = np.rollaxis(img,0,2)
print(img)
img starts as a (5,5) array. That's one value for each of the 25 pixels.
The new array after joining the r,g,b arrays is (3,5,5).
The first rollaxis changes that into a (5,5,3) array.
np.stack([r,g,b], axis=2)
would have done the same.
The second rollaxis swaps the first two dimensions, in effect transposing the original image. (in fact both rollaxis could be replaced with one img.transpose().
Even when you use expand_dims you still make a new array (though it does share the databuffer with the original). But (5,5,1) still doesn't have space to store the 3 color values. The original has 25 values, the new image has 75. You have to make a new array in one way or the other.
To better understand the rollaxis part, I suggest playing with an array like
arr = np.arange(24).reshape(3,2,4)
different sizes in all 3 dimensions make it easier to see the changes in shape.
Related
I've included a zoom functionality similar to the one explained at this website:
http://www.flashandmath.com/howtos/zoom/
This works perfectly on my background image(a map, that is), but I want to keep the symbols on my map the same size while zooming in.
I probably could work this out by changing all the children's size when calling the zoom-function, but I am hoping there is some kind of easy code adapt in my children class to make the size of the instances unchangable. Is there?
Thanks!
One crude way, so you don't have to calculate the symbols scale, would be to remove the symbols from the mapDisplayObject so they're no longer a child and instead put symbol placeholders. Then match each symbol's x and y to each place holder, using localToGlobal...
If your children are not scaled or skewed or rotated you can iterate all of them and set transformation matrix to 1/parentScale. Something like:
for each (var child:DisplayObject in parent) {
var matrix:Matrix = child.transform.matrix;
matrix.a = 1/parentScale;
matrix.d = 1/parentScale;
child.transform.matrix = marix;
}
I feel like this has probably been asked/answered here, and if so, I apologize for the bandwidth, but I don't see any explanation.
How does one translate from one object's coordinate space to another in Flash AS3? I can take a point in an object and translate it to global coordinates using local3DToGlobal() and then to another object's local using globalToLocal3D() -- but is there a direct way?
Thus, if I wanted one object to be able to say to another: 'move your top left corner to my top left corner', even through the two objects are in different z-spaces, rotated 3-dimensionally, etc.
I assume it is in the matrix3D matrix manipulations —
Matrix multiplication? TransformVector()? deltaTransformVector()?
I have been poring over the API but would really appreciate a concrete example.
Thanks!
One approach would be getRelativeMatrix3D(), called from the transform property of a display object, as in: transform.getRelativeMatrix3d(root).position.
Returns a Matrix3D object, which can transform the space of a
specified display object in relation to the current display object's
space. You can use the getRelativeMatrix3D() method to move one
three-dimensional display object relative to another three-dimensional
display object.
From Adobe's Performing complex 3D transformations, there is an example using Matrix3D objects for reordering display, in which faces of a box are reordered to ensure that layering of 3D display objects corresponds to the relative depths after rotations have been applied:
var faces:Array;
for (var i:uint = 0; i < 6; i++)
{
faces[i].z = faces[i].child.transform.getRelativeMatrix3D(root).position.z;
this.removeChild(faces[i].child);
}
faces.sortOn("z", Array.NUMERIC | Array.DESCENDING);
for (i = 0; i < 6; i++)
{
this.addChild(faces[i].child);
}
I'm currently struggling on a problem that seems far beyond my maths capacities (been a long time since I've made some proper maths...) and I would appreciate some help on that.
Here's my setting :
I got some simple shapes (rectangles), and I "project" their bottom points on a line, coming from an Origin point.
Up to this point everything is fine.
But now I'd like to draw the original shape distorted as if it was projected with some perspective on a plane.
Please consider that I have nothing related to any rotation, isometric or any 3D or fake 2D perspective in my code, I'm only trying to draw some shapes using the graphics library to only have a feeling of something real.
Here's a quick drawing of what I'm trying to do :
What I know :
Origin point coordinates
the rect position & sizes
the red line position
the A & B points coordinates
What I want to determine is the coordinates of the C & D points, thing that could be easy if I wasn't struggling to find the "Origin bis" coordinates.
What I'm trying to do is to fake the projection of my rectangle on something that can be considered as a "floor" (related to the plane where my original rectangle is that can be seen as a wall).
Maybe I'm over-complicating the problem or maybe I fail to see any other easier way to do it, but I'm really not good anymore in any geometry or maths thing... :-(
Thanks a lot for your answers !
hmm i don't know if I undestood it correctly but I think you have too few input parameters:
you said the following information is given:
Origin point coordinates
the rect position & sizes
the red line position
the A & B points coordinates
I don't think it is possible to get your projected rectangle with this information alone.
Additionally, I think your green lines and the 'origin Bis' aren't helpful as well.
Perhaps, try this:
Supose, a blue line going through the points C & D is given as well.
Then you could find your projected rectangle by projecting the top of the rectangle onto that blue line.
So in summary:
You define an origin + two parallel lines, a red and a blue one.
Then you can project the top of the rect onto the blue line and the bottom of the rect onto the red line, yielding the points A,B,C,D
I hope this helps.
If I'm right, this code will show what you wanted to see.
First of all, I've ignored your initial setup of objects and information, and focused on the example situation itself; fake-projecting shadow for a "monolith" (any object is possible with the example below, even textured)
My reason was that it's really quite easy with the Matrix class of ActionScript, a handy tool worth learning.
Solution:
You can use the built-in Matrix class to do skew transform on DisplayObjects.
Try this example:
(The "useful" part lies in the _EF EnterFrame handler ;) )
import flash.display.MovieClip;
import flash.geom.Matrix;
import flash.events.Event;
import flash.display.BitmapData;
const PIP180:Number = Math.PI / 180;
const MAX_SHADOW_HEIGHT_MULTIPLIER:Number = 0.25; // you can also calculate this from an angle, like ... = Math.sin(angle * PIP180);
const ANIM_DEG_PER_FRAME:Number = 1.0 * PIP180; // the shadow creeps at a +1 degree per frame rate
var tx:BitmapData = new MonolithTexture(); // define this BitmapData in the library
var skew:Number = -10 * PIP180; // initial
var mono:MovieClip = new MovieClip();
mono.graphics.beginBitmapFill(tx);
// drawn that way the registration point is 0,0, so it's standing on the ground
mono.graphics.drawRect(0, -tx.height, tx.width, tx.height);
mono.graphics.endFill();
// align monolith to the "ground"
mono.x = stage.stageWidth / 2;
mono.y = stage.stageHeight - 100;
// make it be 100x300 pixel
mono.width = 100;
mono.height = 300;
var shad:MovieClip = new MovieClip();
// colored:
shad.graphics.beginFill(0x000000);
// or textured:
//shad.graphics.beginBitmapFill(tx);
shad.graphics.drawRect(0, -tx.height, tx.width, tx.height);
shad.graphics.endFill();
addChild(shad); // shadow first
addChild(mono); // then the caster object
addEventListener(Event.ENTER_FRAME, _EF);
function _EF(e:Event):void {
// animate skew on the positive half circle
skew = (skew + ANIM_DEG_PER_FRAME) % Math.PI;
// Matrix takes 6 parameters: a, b, c, d, x, y
// for this shadow trick, use them as follows:
// a = width scaling (as mono and shad are drawn in the same way, copy mono.scaleX for a perfect fit
// b = 0, because we don't want to project the vertical axis of transformation to the horizontal
// c = horizontal skew
// d = height scaling * skew * making it a bit flat using the constant
// x = mono.x, ...
// y = mono.y since originally mono and shad look alike, only the Matrix makes shad render differently
var mtx:Matrix = new Matrix(mono.scaleX, 0, Math.cos(skew), mono.scaleY * Math.sin(skew) * MAX_SHADOW_HEIGHT_MULTIPLIER, mono.x, mono.y);
shad.transform.matrix = mtx;
}
Now all you got to know to utilize this in your case, is the following N factors:
Q1: from what angle you want to project the shadow?
A1: horizontal factor is the skew variable itself, while vertical angle is stored as constant here, called MAX_SHADOW_HEIGHT_MULTIPLIER
Q2: do you want to project shadow only "upwards", or freely?
A2: if "upwards" is fine, keep skew in the positive range, otherwise let it take negative values as well for a "downward" shadow
P.S.: if you render the internals of the objects that they don't snap to 0 y as a base point, you can make them seem float/sink, or offset both objects vertically with a predefined value, with the opposite sign.
You face 1 very simple problem, as you said:
'What I want to determine is the coordinates of the C & D points, thing that could be easy if I wasn't struggling to find the "Origin bis" coordinates.'
But these co-ordinates relate to each other, so without one (or another value such as an angle) you cannot have the other. If you are to try this in 3D you are simply allowing the 3D engine to define 'Origin bis' and do your calculating for C and D itself.
So regardless you will need an 'Original bis', another value relating to the redline or your Rect for which to calculate the placement of C and D.
I remember making stuff like this and sometimes it's better to just stick with simple, you either make an 'Original bis' defines by yourself (it can be either stationary or move with the player/background) and get C and D the way you got A and B only that you use a lower line than the red line, or as I would of done, once you have A and B, simple skew/rotate your projection from those points down a bit further, and you get something the same as an 'Original bis' that follows the player. This works fine at simulating 'feeling of something real' but sadly as has been said, it looking real depends on what you are portraying. We do not know what the areas above or below the red line are (sky/ground, ground/water) and whether 'Origin' and 'Origin bis' is your light source, vanishing point, etc.
I am trying to get the derived position and scaling of a 3D Sprite and set them to a 2D Sprite.
I have managed to do the first part like this:
var p:Point = sprite3d.local3DToGlobal(new Vector3D(0,0,0));
billboard.x = p.x;
billboard.y = p.y;
But I can't get the scaling part correctly. I am trying this:
var mat:Matrix3D = sprite3d.transform.getRelativeMatrix3D(stage); // get derived matrix(?)
var scaleV:Vector3D = mat.decompose()[2]; // get scaling vector from derived matrix
var scale:Number = scaleV.length;
billboard.scaleX = scale;
billboard.scaleY = scale;
...but the result is apparently wrong.
PS. One might ask what I am trying to achieve. I am trying to create "billboard" 3D sprites, i.e. sprites which are affected by all 3D transformations except rotations, thus they always face the "camera".
The documentation says that you get the vector correctly, but its coefficients don't seem to be added together to form a single length value. Try first an unscaled sprite, and check if you're receiving a sqrt(3) value as its length. If yes, then you should use 0th element of the vector as X scale, and 1th as Y scale. I'm not sure what to do with 2nd element (in this case it'll be a Z scale, either divide both scales by it, or multiply by it). Hope that helped.
I'm trying to position an image on top of another image based upon the make-up of the smaller image. The smaller image is a cut-out of a larger image and I need it to be positioned exactly on the larger image to make it look like a single image, but allow for separate filters and alphas to be applied. As the images are not simple rectangles or circles, but complex satellite images, I cannot simply redraw them in code. I have quite a few images and therefore do not feel like manually finding the position of each image every and hard setting them manually in actionscript. Is there any way for me to sample a small 5-10 sq. pixel area against the larger image and set the x and y values of the smaller image if a perfect match is found? All the images are in an array and iterating through them has already been set, I just need a way to sample and match pixels. My first guess was to loop the images pixel by pixel right and down, covering the whole bitmap and moving to the next child in the array once a match was found, leaving the matched child where it was when the perfect match was found.
I hope I understood your question correctly.
There may be an option that uses copypixels to achieve what you want. You can use the bitmapdata.rect value to determine the size of the sample you want, and loop through the bigger bitmap using thet rectangle and a moving point. Let's see if I can code this out...
function findBitmapInBitmap(tinyimg:BitmapData, largeimg:BitmapData):Point {
var rect:Rectangle = tinyimg.rect;
var xbound:uint = largeimg.rect.width;
var ybound:uint = largeimg.rect.height;
var imgtest:BitmapData = new BitmapData(tinyimg.rect.width, tinyimg.rect.height);
for (var ypos:uint = 0, y <= ybound, y++) {
for (var xpos:uint = 0, x <= xbound, x++) {
imgtest.copyPixels(largeimg, rect, new Point(xpos, ypos);
if (imgtest.compare(tinyimg) == 0) return new Point(xpos, ypos);
}
}
return new Point(-1,-1); // Dummy value, indicating no match.
}
Something along those lines should work - I'm sure there's room for code elegance and possible optimization. However, it seems like something like this method would be very slow, since you'd have to check each pixel for a match.
There is a better way. Split your big image into layers, and use the blitting technique to composite them at runtime. In your case, you could create a ground texture without satellites, and then create the satellites separately, and use the copyPixels method to place them whereever you want. Google "blitting in as3" to find some good tutorials. I'm currently working on a game project that uses this technique and it's a very good method.
Good luck!
Edit: Forgot to code in a default return statement. Using this method, you'd have to return an invalid point (like (-1,-1)) and check for it outside the function. Alternatively, you could just copy your small bitmap to the big one within the function, which would be much more logical, but I don't know your requirements.
You need to find pixel sequence in the big image. BitmapData.getPixel gives you pixel value. So get first pixel from small image, find it in big image, then continue comparing until you find full match. If you have trouble to code that, feel free to ask.
For the actual comparison, there's BitmapData.compare which returns the number 0 if the BitmapData objects are equivalent.