I'm working on an application in which Users can draw lines (with or without arrowheads). Similar to PowerPoint or SnagIt, but on a 3D plane."
Basically I would like to be able to create some line types like in the attached draft:
I've seen the fat lines demo (https://threejs.org/examples/#webgl_lines_fat). But lines don't seem to change width when zooming, and they don't have perspective.
There is also this 3rd party library THREE.MeshLine (https://github.com/spite/THREE.MeshLine) which has some nice features, even dashed lines animation, but before experimenting with it I would like to see what ThreeJS can do by itself.
1) Using ThreeJS Line is there a way to get:
Size and perspective change depending on camera distance/zoom or angle.
Dotted lines (Maybe extending DashedLineMaterial?).
2) Maybe there is a library other than THREE.MeshLine that does what I need?
MeshLine is definitely what you want. Three.js's line implementations are all pixel based and don't really fit your needs. MeshLine is well written and performant, I use it myself for a similar purpose - it'll serve you well.
Related
Ok, so I've been working on a game with some friends for a school project. We have used SFML.
I've been working lately on the camera and a tile implementations system and now I need them to work together.
The camera works like this:
I have two different sf::View, one for the game world and one for the hud. The one for the game world follows the player in the x-axis.
The tile system works in a way where it reads in a txt file and draw sprites based on the information from the txt file.
As it is now I always draw all the tiles, even if it's outside of the cameras view. Not good. I need a way to check if the tiles are outside of the cameras view before I draw them. How do I do this?
I did find this:
Get X and Y offset of sf::View
but I can't really wrap my head around how to make this info work in my game.
Any help would be really appreciated! :)
Mvh Elis
Managed to figure it out after finding this:
http://fr.sfml-dev.org/forums/index.php?topic=10590.0
A few days ago I've explored geomaps and, however, it turned out to be easy to change the properties of the elements.
But I have two questions:
I'd like to add rivers and forests on the maps. So Ive considered to set a background image instead of the geomaps figure. But I can't find a way to get this one fixed. Is there a way to set a background picture for a country or region?
How can I change the shape of the "bubbles" when you select a city e.g. "London"? I'd like to change it to a square.
Thanks in advance for your help!
Unfortunately what you're looking for is not available in geocharts in their current implementation.
Using a background image is possible in the sense that you can use CSS to make all shapes in the map transparent, and use a background image in the div to make it appear as if the little circles are being drawn on a map with forest and rivers, but you will run in to two big hurdles:
Your map will need to be identical in size/layout to the Google Maps SVG
If Google ever changes the SVG they use (or the view/projection they use) you will need to edit yours too
This isn't ideal, obviously. You could work around it by creating custom javascript to write rivers and forests on your map, but that is going to be a huge headache (especially if you are using multiple maps/views).
As for the circles, you can't change them to squares without hacking the actual SVG in the background with javascript. While this is definitely possible (if you're really good with SVG/Javascript), it again isn't using any of the fancy features of geocharts, and is more just a custom solution that will have to be updated if/when google updates their API.
Rather than doing it that way, you may want to look in to the same implementation on google maps itself. That will allow you to use custom markers, draw custom shapes, etc. with a lot more flexibility (and a much more stable API).
I am currently working on skeletal animation tests in three.js. I have a simple model which animates just fine in blender. Basically it consists of three stacked, bending cubes.
When I export the blender file to the three.js using the blender export plugin with Blender V2.64, the animation in the webGl context appears different as if the skinweighting is wrong.
WebGL-Demo:
http://rainbowrangers.de/threejs/animation_test01/
Blender-File:
http://rainbowrangers.de/threejs/animation_test01/model/animation_test01.blend
What do I have to do to get the correct result in three.js?
I am the person you quoted from the github discussion. I have recently been experimenting with this pipeline, ( ie Blender bone animations into threejs,) and have found that it is very very difficulty to find a reliable process that will work every time.
On my blog, I have compiled a list of 'tips' that allowed me to achieve success on some occasions:
http://dev.mothteeth.com/2012/10/threejs-blender-exporting-skeletal-animations/
To summarise, the most important things I found were:
Delete the Armature Modifier before exporting, or the animation will be all messed up.
Check that your Vertex Groups are properly assigned to the bones. ( In Blender, you can use automatic bone weights. )
Key all bones in the first and last frames of your animation. ( As you discovered, if you only have keys for the bones you have changed, ThreeJS won't infer anything about the other ones, and things will be broken. )
Even following these guidelines, I can't get things to work consistently, and have been considering using morph targets until the library matures a bit more. The file sizes for morph targets are much larger but they seem to be a more reliable option at this point, in my experience.
After a lot of digging I finally found the answer in one of the three.js github discussions:
"Insert a full keyframe for all of the bones at the beginning and end of the animation. I found that without the first keyframe the animation would be subtly distorted, and without the one at the end I would lose parts of the animation toward the end."
Source: https://github.com/mrdoob/three.js/issues/2106
That was exactly what happened to our render. We only hat keyframes set for the bones that were changing and not for the static ones.
I've also found that to get the exported model working right the export should be done at frame 0 in Blender.
Another thing that solved a problem I've encountered was not to scale model after exporting it. This means that the model can't be scaled in the JSON file and probably in the code directly.
Using three.js r56
I want to create something like a leaflet/magazine using Latex. Is it possible to place text on top of an image and style the text freely?
Any links to examples of something like this?
I usually do something like
\usepackage{tikz}
...
\begin{tikzpicture}
\draw (0, 0) node[inner sep=0] {\includegraphics[width=4cm]{imagefile.png}};
\draw (1, 1) node {Hello world};
\end{tikzpicture}
A very good toolset for manipulating images is pgf/TikZ pdf doc.
See \pgfimage for examples. It allows to mix text and image freely. There are many ways to do it. One of them is to use layers (p. 220 of pgfmanual). The pgf manual contains many simple examples, and is very precise.
Another solution is to use the lpic package: the homepage contains some examples.
You can find other examples for pfg and TikZ here and here for many impressive examples.
You can also define the text after the image and then offset it using negative vertical space. Because it follows after the image in the LaTeX source, it will be drawn on top of the image instead of underneath it.
\includegraphics[...]{...}
\vspace*{-20ex} % Tune this to the image height.
\begin{center}
Text
\end{center}
\vspace*{20ex} % The spacing above but without the minus.
Another solution is the textpos package which allows you to specify boxes at absolute positions on the page. The boxes can overlap, so you can put the figure in one box, and text in another box on top of it.
I realise that the question is old and answer is accepted, but for completeness would like to propose an alternative approach for making leaflets in LaTeX.
Specifically, the leaflet document style served me really well for this purpose.
A good blog post wrt background image can be found here. There are a couple of packages that are required to use in order to make the proposed approach work, but were not mentioned in the blog post:
\usepackage[usenames,dvipsnames]{xcolor}
\usepackage{transparent}
As already suggested, you can annotate the different parts of the figure using TikZ. However, sometimes it might even better to use numbers to reference the different parts and explain them in the figure caption.
To easily get the precise relative positions (which is often tedious) and to generate LaTeX code automatically, you could use the new web-based LaTeX Overlay Generator, which I built for such cases. This is just a small interactive tool, which helps you to find the right locations.
Another way to do this, admittedly not using LaTeX, would simply be to edit the image with photoshop or gimp or something like that. I guess your option in terms of typesetting mathematics might be fairly limited doing it this way.
Otherwise I'd endorse using tikz.
Are you sure you want to do it in LaTeX? Desktop publishing software might be more suited to your needs... Something like scribus might be easier than tikz in terms of learning curve, depending on what you want to do.
I'd like to add on to #midtiby's answer...
You can also specify the text position using a relative position, like so:
\usepackage{tikz}
...
\begin{tikzpicture}
\node[inner sep=0] (image) at (0,0) {\includegraphics[width=4cm]{imagefile.png}};
\node[above=0 of image] {Hello world};
\end{tikzpicture}
I am trying to do animations on iPhone using OpenGL ES. I am able to do the animation in Blender 3D software. I can export as a .obj file from Blender to OpenGL and it works on iPhone.
But I am not able to export my animation work from Blender 3D to OpenGL. Can anyone please help me to solve this?
If you have a look at this article by Jeff LaMarche, you'll find a blender script that will output a 3D model to a C header file. There's also a followup article that improves upon the aforementioned script.
After you've run the script, it's as simple as including the header in your source, and passing the array of vertices through your drawing function. Ideally you'd want a method of loading arbitrary model files at runtime, but for prototyping this method is the simplest to implement.
Seeing as you already have a method of importing models (obj) then the above may not apply. However, the advantage of using a blender script is that you can then modify the script to suit your own needs, perhaps also exporting bone information or model keyframes.
Well first off, I wouldn't recommend .obj for this purpose since the obj file format doesn't support animation, only static 3D models. So you'll need to export the animation data as a separate file that you load at the same time as the obj.
Which file format I would recommend depends on what exactly your animations are. I don't remember off the top of my head what file formats Blender supports, but as I recall it does not export Collada files with animation, which would be the most general recommendation. Other options would be md2 for character animations, or 3ds for simple "rigid objects moving around" animations. I think Blender's FBX exporter will work, although that file format may be too complicated for your needs.
That said, and assuming you only need simple rigid object movements, you could use .obj for the 3D model shapes and then write a simple Python script to export a file from Blender that has at the keyframes listed, with the frame, position, and rotation for each keyframe. Then load that data in your code and play back those keyframes on the 3D model.
This is an old question and since then some new iOS frameworks have been released such as GLKit. I recommend relying on them as much as possible when you can, since they take care of many inherent conversions like this, though I haven't researched the specifics. Also, while not on iOS, the new Scene Graph technology for OS X (which will likely arrive on iOS) in the future, take all this quite a bit further and a crafty individual could do some conversions with that tool and then take the output to iOS.
Also have a look at SIO2.
I haven't used recent versions of Blender, but my understanding is that it supports exporting mesh animation as a sequence of .obj files. If you can already display a single .obj in your app, then displaying several of them one after another will achieve what you want.
Now, note that this is not the most efficient form to export this type of animation, since each .obj file will have a lot of duplicated info. If your mesh stays fixed over time (i.e. only the vertices move with the polygon structure, uv coords, etc. all fixed) then you can just import the entire first .obj and from the rest just read the vertex array.
If you wanted to optimize this even more, you could compress the vertex arrays so that you only store the differences from the previous frame of the animation.
Edit: I see that Blender 2.59 has export to COLLADA. According to the Blender manual, you can export object transformations, and you can also export baked animation for rigged objects. The benefit for you in supporting the COLLADA format in your iPhone app is that you are free to switch between animation tools, since most of them export this format.