Display many thousand images in three.js - three.js

I have up to 200'000 individual images in a scene (done with sprites, so far). I want to look at these sprites, and when I fly around they should always face the camera (as sprites do).
My question is: How can I achieve the best performance WebGL-wise? Are Sprites with useScreenCoordinates:false rendered as with GL_POINT?
At the moment the fps drops with very low image counts already. I'm using mipmapping and sprites so far. And since they need to turn around to face me I didn't want to use BufferGeometry..
I'd highly appreciate some ideas and inputs :) Thanks!
PS: Point of it all is that you can "fly" through 200'000 images and stop/select the ones you figure to be interesting

My team needed to accomplish this too, and sadly Doidel's notes trail off before the project is completed. We developed PixPlot, a three.js visualization layer for images:
I put together a blog post outlining the details here: http://douglasduhaime.com/posts/visualizing-tsne-maps-with-three-js.html
In short, if others face this problem, you'll want to create one geometry (ideally) with one large image atlas (a single jpg of size 2048px by 2048px containing lots of smaller images) serving as the texture for the geometry. Add vertices, faces, and vertexUV's for each of the little images to display, and pull each image from the atlas texture.

Used tons of techniques and stuff, I'll be writing about it on http://blogs.fhnw.ch/threejs/ once I got it all working

Related

WebGL vs CSS3D for large scatter plot of images

I am building a web application which will display a large number of image thumbnails as a 3D cloud and provide the ability to click on individual images to launch a large view. I have successfully done this in CSS3D using three.js by creating a THREE.CSS3DObject for each thumbnail and then append the thumbnail as an svg:image.
It works great for upto ~1200 thumbnails and then performance starts to drop off (very low FPS and long load time). By the time you hit 2500 thumbnails it is unusable. Ideally I want to work with over 10k thumbnails.
From what I can tell I would be able to achieve the same result by creating each thumbnail as a WebGL mesh with texture. I am a beginner with three.js though, so before I put in the effort I was hoping for guidance on whether I can expect performance to be better or am I just asking too much of 3D in the browser?
As far as rendering goes, CSS3 should be relatively okay for rendering quite big amount of "sprites". But 10k would probably be too much.
WebGL would probably be a better option though. You could also take care about further optimizations, storing thumbnails in atlas texture or such...
But rendering is just one part. Event handling can be serious bottleneck if not handled carefully.
I don't know how you're handling mouse clock event and transition towards fullsize image, but attaching event listener to each of 2.5k+ objects probably isn't a good choice anyway. With pure WebGL you could use imagespace for detecting clicked object. Encoding each tile with different id/color and using that to determine what's clicked. I imagine that WebGL/CSS3D combo could use this approach as well.
To answer question, WebGL should handle 10k fine. Maybe you'll need to think about some perf optimization if your rectangles are big and they take a significant amount on the screen, but there are ways around it if that problem appears.

Creating a 3D map with 2D depth images in PROCESSING

I'm creating a 3D map with 2D depth images in Processing. I have captured the images using saveFrame(), however I am having difficulty in converting those saved frames into 3D. Is there any website or code I could look through for help? Any help would be much appreciated.
Before i'm going to go in-depth into your question, i want to mention that instead of saveFrame() you can use the standard dfx library to export 3d models instead of 2d images using Processing if you simply want to store a scene:
https://processing.org/reference/libraries/dxf/
Now back to your question. First of all what are depth images? Are those simply saveFrames from a 3D Scene in Processing (P3D) or are these special images, because depth is quite a general term. If they are 3D Scenes and you would know the coordinates of the camera and their viewangle the task gets quite easier, but it is technically impossible to create a 3D object using only 2D images without XRay. Imagine looking at a fork. Your eyes are making 2 pictures of that fork, however you have no idea what might be inscribed on the back of that fork. No matter how many pictures you might have of your 3D scene, you won't be able to convert it into 3D perfectly. That said, this is indeed a general problem in computer science and there are various methods to solve this. Wikipedia has an article on it:
http://en.wikipedia.org/wiki/3D_reconstruction_from_multiple_images
http://en.wikipedia.org/wiki/2D_to_3D_conversion
Here are a few stackoverflow topics which might help you get started:
3d model construction using multiple images from multiple points (kinect)
How to create 3D model from 2D image
Converting several 2D images into 3D model

Make a mesh unprintable, but still viewable with three.js

Is there a way to make a mesh unprintable with a 3D printer, but still viewable with three.js.
Motivation is that I want to show users a preview of a mesh before he can buy it. But as the JS code is viewable he could download it without paying for it. Degrading the quality of the preview mesh would be a way, but as the quality of the mesh is a selling point I would like to avoid that.
My idea was to add some kind of triangulation defects which would prevent the printing of the mesh, but which would not prevent threejs from showing the mesh.
Tools like Netfabb or Meshlab should also not be able to automatically repair the mesh.
Is there something like a bad sector copy protection equivalent for 3d models?
Just a few ideas.
1) Augment your shaders to ignore some interval of vertices from the buffer (like every 3rd or something). In this way you can add "garbage" to the model file so it can not be lifted easily from the network.
2) Once in the buffer it can still be pulled out with a savvy user, unless you split the model up into many chunks and render out of order or only render the front half of the model making it less useful for 3D printing. One could also render in split views or using stereoscopic interlaced with a separation of zero.
3) Only render a none symmetrical half of your model with an camera control locked to that half :P
Kinda wonky, a ton of work to implement, and still someone will find a way I'm sure. But that's my two cents worth anyway, hope it helps.
I've seen some online shops preview with renders taken from each 10-30 degrees around the model. That way you only pass the resulting image, not the model.
why not show a detailed HD video of your model?
If the mesh is non-manifold it will not print.
a) Render serverside, stream results in an interactive video
b) destroy the mesh while still keeping the normals intact for shading. You can randomly flip faces, render with double sided. You can "extrude" edges to mess up topology. As long as you map the normals correctly, it will shade without any of these defects affecting it.

Three.js How to increase canvas-text texture quality

What parameters, modes, tricks, etc can be applied to get sharpness for texts ?
I'm going to draw a lot so I cant use 3d text.
I'm using canvas to write the text and some symbols. I'm creating somethinbg like label information.
Thanks
This is no simple matter since you'll run into memory issues with 100k "font textures". Since you want 100k text elements you'll have several difficulties to manage. I had a similar problem too once and tossed together a few techniques in order to make it work. Simply put you need some sort of LOD ("Level of Detail") to make that work. That setup might look like following:
A THREE.ParticleSystem built up with BufferGeometry where every position is one text-position
One "highres" TextureAtlas with 256 images on it which you allocate dynamically with those images that are around you (4096px x 4096px with 256x256px images)
At least one "lowres" TextureAtlas where you have 16x16px images. You prepare that one beforehand. Same size like previous, but there you have all preview images of your text and every image is 16x16px in size.
A kdtree data structure to use a nearestneighbour algorithm with to figure out which positions are near the camera (alike http://threejs.org/examples/#webgl_nearestneighbour)
The sub-imaging module to continually replace highres textures with directly on the GPU: https://github.com/mrdoob/three.js/pull/4661
An index for every position to tell it which position on the TextureAtlas it should use for display
You see where I'm going. Here's some docs on my experiences:
The Stackoverflow post: Display many thousand images in three.js
The blog where I (begun) to explain what I was doing: http://blogs.fhnw.ch/threejs/
This way it will take quite some time until you have satisfying results. The only way to make this simpler is to get rid of the 16x16px preview images. But I wouldn't recommend that... Or of course something depending on your setup. Maybe you have levels? towns? Or any other structure where it would make sense to only display a portion of these texts? That might be worth a though before tackling the big thing.
If you plan to really work on this and make this happen the way I described I can help you with some already existing code and further explanations. Just tell me where you're heading :)

Image Transformation

I've been reading a lot about information transformations/distortions on here and elsewhere, and they seem to fall into two categories: distortion of the pixels of the image while maintaining the original boundaries, or transformations like rotation, scaling, etc. What I would like to do is pretty different.
I would like to warp a rectangular image into a polygon. In particular, I want to warp an image into each one of the 50 United States. Simple mapping of the state and then cropping out parts of the image that don't fit in is not acceptable. These images have borders, and then someone's face contained inside of them. I did find this really cool paper on content-aware image resizing (paper), and while it would let me keep the focus of the images (the face) undistorted, it still maps to 4 corners. For my initial test, I don't care about warping the faces too.
Does anyone have suggestions? Research papers, code, Wikipedia pages, GIMP plugins, software tools, etc welcome.
See if multipoint distortion in ImageMagick can work for you.

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