I have a curtain I want to render in my ARKit app. I added all parts of my curtain (exported as COLLADA) and added them in my .scn file and placed them so that they line up properly and form a correct curtain.
Now I have added the file to the ARKit testing app and it seems like all individual objects rotated around the X-axis of their own coordinate system.
Why is this? Does it have something to do with Y vs Z being up?
Blender's coordinate system uses Z-up, but SceneKit uses Y-up. I believe that's where your issue is stemming from.
SCNScene has an initializer with loading options, try using the convertToYUp option. This could be done at runtime or before with a custom command line tool.
Here's an example of how to load a Collada file with the convert Y-up option, then exported to the url destination of your choice.
let scene = try? SCNScene(url: daeURL, options: [.convertToYUp: true])
scene.write(to: scnURL, options: nil, delegate: nil, progressHandler: nil)
I've been very happy with the results. SceneKit is able to convert not just single objects but multiple objects in complex scenes.
Just remember to apply rotation in Blender before exporting to get good results. I believe the hotkey to apply rotation is Ctrl+A, then R.
Related
I followed multiple example, to train a custom object detector in TensorflowJS . The main problem I am facing every where it is using pretrained model.
Pretrained models are fine for general use cases, but custom scenario it fails. For example, take this this is example form official Tensorflowjs examples, here it is using mobilenet, and mobilenet and mobilenet has image size restriction 224x224 which defeats all the purpose, because my images are big and also not of same ratio so resizing is not an option.
I have tried multiple example, all follows same path oneway or another.
What I want ?
Any example by which I can train a custom objector from scratch in Tensorflow.js.
Although the answer sounds simple but trust me I searching for this for multiple days. Any help will be greatly appreciated. Thanks
Currently it is not yet possible to use tensorflow object detection api in nodejs. But the image size should not be a restriction. Instead of resizing, you can crop your image and keep only the part that contain your object to be detected.
One approach will be like partition the image in 224x224 and run for all partitions but what if the object is between two partitions
The image does not need to be partitioned for it. When labelling the image, you will need to know the x, y coordinates (from the top left) and the w, h of the detected box. You only need to crop a part of the image that will contain the box. Cropping at the coordinates x - (224-w)/2, y- (224-h)/2 can be a good start. There are two issues with these coordinates:
the detected boxes will always be in the center, so the training will be biaised. To prevent it, a randomn factor can be used. x - (224-w)/r , y- (224-h)/r where r can be randomly taken from [1-10] for instance
if the detected boxes are bigger than 224 * 224 maybe you might first choose to resize the video keeping it ratio before cropping. In this case the boxe size (w, h) will need to be readjusted according to the scale used for the resizing
I can make 2D dimensional netcdf maps of some quantity. I open it in panoply and there is color map of that quantity. But I cannot visualize some boolean value.
Can I somehow mark particular grid points with some symbol on the map (it can be diamond, square, triangle... whatever), is there a way how to do it in Fortran90? I accept also python related help.
Again: I mean there would be color map (from real values) (which I can do) and at the same time some values will have e. g. triangle on it.
If I understand the question correctly, then you can easily do that with Python and using some plotting library (e.g Matplotlib). With Fortran it is extremely tricky as it does not natively support plotting in my mind.
Basically with Python you just have to :
read the wanted variables (coordinates and the field itself)
make the map of the field i.e make the plot
find the locations you want to highlight and just add those locations to the plot
I'm writing a method to parse the data in wavefront obj files and I understand the format for the most part, however some things are still a bit confusing to me. For instance, I would have expected most files to list all the vertices first, followed by the texture and normal map coordinates and then the face indices. However, some files that I have opened alternate between these different sections. For instance, one .obj file I have of the Venus de Milo (obtained here: http://graphics.im.ntu.edu.tw/~robin/courses/cg03/model/ ) starts off with the vertices (v), then does normal coordinates (vn), then faces (f), then defines more vertices, normals and faces again. Why is the file broken up into two sections like this? Why not list all the vertices up front? Is this meant to signify that there are multiple segments to the mesh? If so, how do I deal with this?
Because this is how the file format was designed. There is no requirement for a specific ordering of the data inside the OBJ, so each modelling package writes it in its own way. Here is one brief summary of the file format, if you haven't read this one yet.
That said, the OBJ format is quite outdated and doesn't support animation by default. It is useful for exchanging of static meshes between modelling tools but not much else. If you need a more robust and modern file format, I'd suggest taking a look at the Collada format or the FBX.
not an direct answer but it will be unreadable in comment
I do not use this file-format but mesh segmentation is usually done for these reasons:
more easy management of the model for editing
separation of parts of model with different material or texture properties
mainly to speed up the rendering by cut down unnecessary material or texture switching
if the mesh has dynamically moving parts then they must be separated
Most 3D mesh file formats contains also transform matrix for each mesh part and some even an skeleton hierarchy
Now how to handle segmented meshes:
if your engine supports only unsegmented models then merge all parts together
This will loose all the advantages of segmented mesh. Do not forget to apply transform matrices of sub segments before merging
or you can implement mesh segmentation into your model class
By adding model hierarchy , transform matrices , ...
Now how to handle mixed model fileformat:
scan file for all necessary chunks of data
remember if they are present
also store their size,and start address in file
and do not forget that there may be more that one chunk of the same data type
preallocate space for all data you need
load/merge all data you need
load chunks of data to you model classes or merge it to single model
of course check if all data needed id present like number of points match number of normals or texture coords ...
I'm currently doing my A-Level Computing project for which I am making my own version of the classic game Space Invaders.
To create the wave of space invaders I want to use a 2D array of images, where the images are loaded from a disk and then displayed on the form but I am unsure of how load the images into the array and then display the array on a form.
The current arrays are:
ImagePaths:array [1..3] of string =('SpaceInvader1.jpg', 'SpaceInvader2.jpg', 'SpaceInvader3.jpg');
Wave:array[1..11, 1..5] of TImage; x,y:integer;
What I would like to know is: how would I load an image into an array element? eg how would I load 'SpaceInvader1.jpg' to array element [1,1]?
Any help would be greatly appreciated.
If you're going to be coding graphical animations, you probably won't want to do it directly on the form. Trying to move things around can be tricky, especially if you want to animate smoothly and not get a lot of flicker and graphical artifacts.
It would be better to use a rendering library. The workflow goes like this:
Create a rendering context on the form. This is a control that provides a surface for graphical animations to run on.
Load your three images into memory.
Create an array of objects to represent the game data associated with your monsters. (Position, movement direction and speed, etc.) It can be flat or 2D, whichever works better for you.
Set up a render loop that goes like this:
For each monster in the array, draw it at its position.
Draw the player's ship and all projectiles.
Check for collisions and handle appropriately.
Check for player input and handle appropriately.
You can find plenty of information on rendering libraries for Delphi in the forums at Pascal Game Development.
You have the following declarations:
ImagePaths:array [1..3] of string =(
'SpaceInvader1.jpg',
'SpaceInvader2.jpg',
'SpaceInvader3.jpg'
);
Wave: array[1..11, 1..5] of TImage;
You want to know how to populate the array of images. It is quite wasteful to create 55 images when 3 will suffice. So instead of that, use indirection. Store references to the images. And TImage is a visual component, and so not appropriate for a sprite.
I would hold the images in an array like this:
Sprites: array [1..3] of TBitmap;
And populate it
JPEGImage := TJPEGImage.Create;
try
for i := 1 to 3 do
begin
JPEGImage.LoadFromFile(ImagePaths[i]);
Sprites[i] := TBitmap.Create;
Sprites[i].Assign(JPEGImage);
end;
finally
JPEGImage.Free;
end;
Then populate your Wave array like this, for example:
Wave: array[1..11, 1..5] of TBitmap;
....
for i := 1 to 11 do
for j := 1 to 5 do
Wave[i,j] := Sprites[1];// or whichever sprite you want
Of course your sprites may be better with a real name rather than in an array.
Some other comments:
JPEG is a bad format for a game sprite. It is a lossy format. A plain Windows bitmap would be fine, as would a GIF or PNG.
I'd much rather see the images as embedded resources. Then your executable can stand alone.
I'd also far rather see your Waves array holding the state of each invader. And then you would create a function that would render that state onto a canvas.
I am programming a basic GUI in MATLAB that utilizes the mapping toolbox. The GUI will display a grayscale image and then plot discrete points over the data, all of this over the necessary map projection. It is important that I plot onto map axes (those created by the axesm command) rather than the vanilla cartesian space. I have no problem doing all this from the command line, but I cannot find a way to implement a GUI version and its driving me nuts.
The problem is that I need to specify the map axes as being the child of the parent figure. The normal axes has a property that can be set, doing something like:
axesHandle = axes('Parent', parentHandle, ...);
or
set(axesHandle, 'Parent', parentHandle);
However, there is no equivalent parent property for the map axes created by the axesm function, so I have no way to manipulate the axes within the figure. How can I do this?
Update: If I create a plot within the map axes in an empty figure, get(figureHandle, 'Children') returns the handle of the axesm object (thanks #slayton!), so the map axes object must be implicitly added to the children of the figure by MATLAB.
Should I be concerned that the map axes do not refer back to the parent figure, or should I just let it be? I wonder if this is a classic case of MATLAB forcing me to not comply with the standards the manual tells me to implement.
From reading your question what I think you are trying to do is grab the handle of the axes object. This can be done as the axes is created using either axes or subplot
a = axes();
a = subplot(x,y,z);
% both return an handle to the newly created axes object
Additionally if the axes is created automagically by a function call like plot or image you can get the axes handle that too:
p = plot(1:10); %returns a handle to a line object
a = get(p,'Parent');
i = image(); %returns a handle to an image object
a = get(i, 'Parent');
Finally, neither of those two options is available you can always get the axes handle from its containing figure with:
a = get(figureHandle, 'Children');
Remember though that this will return a vector of axes handles if your figure contains more than one axes.
Finally when it comes time to draw draw your points to the axes that contains your map image you simply need to call:
line(xPoints, yPoints, 'linestyle', 'none', 'marker', '.', 'color', 'r', 'size', 15)
This will draw the vertices of the line using large red dots.
I'm not sure if this answers your question because the code you provided doesn't line up with the question you asked.
The code you provided looks like you are trying to move an axes from one figure to another. You can totally do this!
f = figure('Position', [100 100 100 100]);
a = axes('Parent', f);
pause
f2 = figure('Position', [250 100 100 100]);
set(a,'Parent', f2);
After much trial and error and reading of documentation, I have found that there is no way to explicitly specify the parent of the map axes. Instead, they are implicitly added on top of the current axes. In the instance that no axes exist in the current figure, calling axesm creates an axes object and then places the axesm object inside. When you take this route, you have to grab the axes object handle by calling gca:
mapAxesHandle = axesm(...);
axesHandle = gca(...);
This makes it frustrating to use the mapping toolbox when writing a GUI from scratch, but that's the way Mathworks makes it happen. Thanks to #slayton for useful info. I'd upvote but my reputation is <15 :(