I have a VTK data file for a 3D model and I am trying to show a transformation applied to it.
I have the point coordinates/polygon data for every state in the transformation (there should be about 10-30 states), i.e. I could write another VTK file for each step.
I am trying to create a nice animation where each state would be shown for say, 1 second and then switch to the next one, as fluently as possible.
What would be the best thing to do?
There are a handful of ways to animate something in VTK, with examples on the VTK Wiki.
The easiest way is probably to subclass vtkCommand (DataAnimationSubclass), but the "VTK/right" way is with vtkAnimationScene (AnimationScene).
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I'm making an isometric city builder using Monogame Extended and Tiled. I've got everything set-up and now i need to somehow access the specific tiles so i can change them at runtime as the user clicks on a tile to build an object. The problem is, i can't seem to find a "map.GetLayer("Layername").GetTile(x,y) or .SetTile(x,y) function or something similar.
Now what i can do is edit the xml(.tmx) file which has a matrix in it that represents the map and it's drawn tiles. The problem with this is that i need to build the map in the content pipeline again after editing for the changes to be displayed. I can't really build at runtime or can i?
Thanks in advance!
Something like this will get you part way there.
var tileLayer = map.GetLayer<TiledMapTileLayer>("layername");
TiledMapTile tile;
if(tileLayer.TryGetTile(x, y, out tile))
{
// do something with tile
}
However, there's only a limited amount of things you can actually do with the tile once you've got it from the map.
There's no such thing as a SetTile method because changing tile data at runtime is not currently supported. This is a limitation of the renderer, which has been optimized for rendering very large maps by building static geometry that can't be changed once it's loaded into the graphics card.
There has been some discussion about building another renderer that would handle dynamic map changes but at this stage nothing like that has been implemented in the library. You could always have a go at implementing a simple renderer yourself, a really basic one is not as hard as you might think.
An alternative approach to dealing with this kind of problem might be to pre-process the map data before giving it to the renderer. The idea would be to effectively separate the layers of the map that are static from those that are dynamic and render the dynamic tiles as normal sprites. Just a thought, I'm not sure about the details of how this might work.
I plan to eventually revisit the Tiled API in the next major version of MonoGame.Extended. Don't hold your breath, these things can take a lot of time, but I am paying attention to the feedback and kinds of problems people are experiencing with the existing API.
Since the map data is stored in a XML (or csv) file which runs through the Content Pipeline you can not change it at runtime.
Anyways, in a city builder you usually do not change existing tiles but you place object on top of existing tiles.
Does anyone know of macro or custom command I can make to quickly annotate the area of a polyline in autocad?
I'm doing a project where I need to measure the lot and house size of several city blocks. I've got a drawing going but I don't want to measure and write out the area of each site, that will take to long. I've seen custom commands in the past that quickly do this kind of thing but I don't know how to make my own.
And I'm desperately avoiding doing it by hand one at a time as most likely I will need to make adjustments to my design later on.
The best method I can think of is to utilize the MTEXT command and use a FIELD to link the Area of the Polyline to the MTEXT box.
Type FIELD at the command line, choose Object, select your Polyline and you will see the Area property.
Here is a link on the CADTutor site that covers it a bit more in depth along with a link to a forum post that has this automated via a Lisp routine.
http://www.cadtutor.net/forum/archive/index.php/t-46628.html
When I use the following,
imshow(imread('image1.jpg'));
imshow(imread('image2.jpg'));
imshow(imread('image3.jpg'));
imshow(imread('image4.jpg'));
imshow(imread('image5.jpg'));
imshow(imread('image6.jpg'));
I got only image named image6.jpg in the output figure.
There is also an option figure,imshow(...); to view all the images each in new window.
But writing figure in each line where I need to view the image is a repeated and tedious process. Is there any other solution to get the same output as with figure,imshow(..);
without using figure function.
I mainly put on this question because while programming a lot somewhere we forget to use the figure function and so the image that we need to view wont be visible. It would have been overwritten by other image. So provide me some solution.
I ask this only for simplicity in writing the code. So if there is any solution, please mention.
Thanks in advance.
I'm not sure, but I don't think that there's a workaround to that. MATLAB basically changes the current figure handle to that of a new image when you use imshow. One thing you can do however is to make a copy of imshow in your local directory and edit it accordingly to make your own UDF.
What I would recommend however (so as to preserve functionality across systems) is that you open your code is an editor and replace all imshows with figure, imshow. This should be easy enough and it'll be easy to revert back as well.
First of all, I know that displays lists were deprecated in OpenGL 3.0 and removed on 3.1. But I still have to use them on this university project for which OpenGL 2.1 is being used.
Every article or tutorial I read on display lists use them on some kind of object that is drawn multiple times, for instance, trees. Is there anything wrong in creating one list for a single object?
For instance, I have an object (in .obj format) for a building. This specific building is only drawn once. For basic performance analysis I have the current frames per second on the window title bar.
Doing it like this:
glmDraw(objBuilding.model, GLM_SMOOTH | GLM_TEXTURE);
I get around 260 FPS. If you don't about the GLM library, the glmDraw function basically makes a bunch of glVertex calls.
But doing it like this:
glNewList(gameDisplayLists.building, GL_COMPILE);
glmDraw(objBuilding.model, GLM_SMOOTH | GLM_TEXTURE);
glEndList();
glCallList(gameDisplayLists.building);
I get around 420 FPS. Of course, the screen refresh rate doesn't refresh that fast but like I said, it's just a simple and basic way to measure performance.
It looks much better to me.
I'm also using display lists for when I have some type of object that I repeat many times, like defense towers. Again, is there anything wrong doing this for a single object or can I keep doing this?
Using display lists for this stuff is perfectly fine and before Vertex Arrays were around they were the de-facto standard to place geometry in fast memory. Put display lists have a few interesting pitfalls. For example in OpenGL-1.0 there were no texture objects; instead placing the glTexImage call in a display list was the way to emulate this. And this behaviour still prevails, so binding a texture and calling glTexImage in a display list will effectively re-initialize the texture object with what's been done in the display list compilation, whenever the display list is called. On the other hand display lists don't work with vertex arrays.
TL;DR: If your geometry is static, you don't expect to transistion to OpenGL-3 core anytime and it gives you a huge performance increase (like it did for you), then just use them!
I'm writing a video annotation application with Qt4 in which users need to be able to seek to various points in a video, putting markers on various objects and then setting keypoints for those markers so that they stay on the objects in the video as they move around. QGraphicsItemAnimation seems like a great place to start for these markers, however they need to be able to appear and disappear at specific times, which I can't figure out how to do with the QGraphicsItemAnimation. I could set the scale at 0 to make the objects disappear, but that seems like a pretty hacky solution, and I'm guessing that the paint engine would still waste cpu cycles trying to draw those invisible objects. Does anyone have a better solution than this? I'm using Qt 4.5.3 right now, but I'm willing to upgrade to 4.6 if it makes things easier. Thanks!!
It seems like the functionality you want of showing/hiding QGraphicsItem objects is beyond the scope of the simple "tweening" that the animation class performs. It is only for one object at a time, and any appearance or disappearance you have to write yourself.
You still might get some mileage out of QGraphicsItemAnimation (although the fact that it uses its own timer instead of being locked to the frame clock of your video is a little dodgy).
Neglecting "seeking" for a moment, there is a QTimeLine::finished() signal. If you let the end of an annotation's active animation timeline represent the point where you want it to disappear, you can trigger QGraphicsItem::hide() at that point. When it comes time to turn it back on, you would construct a new QGraphicsItemAnimation (based on the next run of keyframe data for that object) and call QGraphicsItem::show().
Note that one of the headlining features of Qt 4.6 is the QtAnimation framework, which is more sophisticated but also rather complex. I've not used it yet, but looking over the examples it seems like you might be able to "animate" a visibility or opacity property.