I'm struggling with a visualization I'm working on that involves a stream of repeated images. I have it working with a single sprite with a ParticleSystem, but I can only apply a single material to the system. Since I want to choose between textures I tried creating a pool of Particle objects so that I could choose the materials individually, but I can't get an individual Particle to show up with the WebGL renderer.
This is my first foray into WebGL/Three.js, so I'm probably doing something bone-headed, but I thought it would be worth asking what the proper way to go about this is. I'm seeing three possibilities:
I'm using Particle wrong (initializing with a mapped material, adding to the scene, setting position) and I need to fix what I'm doing.
I need a ParticleSystem for each sprite I want to display.
What I'm doing doesn't fit into particles at all and I really should be using another object type.
All the examples I see using the canvas renderer use Particle directly, but I can't find an example using the WebGL renderer that doesn't use ParticleSystem. Any hints?
Ok, I am going from what I have read elsewhere on this github issues page. You should start by reading it. It seems that the Particle is simply for the Canvas Renderer, and it will become Sprite in a further edition of Three.JS. ParticleSystem, however is not going to fulfill your needs either it seems. I don't think these classes are going to help you accomplish this in WebGL in 3D. Depending on what you are doing you might be better off with the CanvasRenderer anyway. ParticleSystem will only allow you to apply a single material which will serve as the material for each particle in the system as you suggested.
Short answer:
You can render THREE.Particle using THREE.CanvasRenderer only.
Related
I try to implement a scene, where an object is updated in different way for each eye (eg. I want to project opposite rotation of box for each eye).
I have demo application written with WebGL using Three.js as described in Google Developers tutorial.
But there is only one scene, containing one mesh, with single update function. I can't find way to implement separation of update, so it's done seperately for each eye (just as rendering is done) and wonder if it's even possible.
Anybody has any experiences with similar case?
Your use case is rather unusual (and may I say, eye-watering), so basically the answer is no: Three.js has abstracted away the left/right eye dichotomy of VR. Internally it renders the scene using an array of 2 camera's, with the correct left/eye setting.
Fortunately, every object has an onBeforeRender(renderer, scene, camera, ...) event. If you hook that event, and find a way to distinguish the left/right eye camera you should be able to modify the orientation just before it gets rendered.
A (perhaps too) simple way to distinguish the camera's would be to keep a track of the index with a counter.
I have a photo-realistic scene already created in 3ds max. I want to render the scene on the web using WebGl and three.js. TO get the realistic effects created in 3ds max using mental ray renderer, I tried to bake the light maps from 3ds max to JPEG files and then map objects in three.js to the texture(exported JPEG) files. But the efeects in three.js seem to be stretched out and not positioned properly. Is my approach correct in the first place? If yes, could it be a problem with the UV mapping from the 3ds Max? Please provide some links if possible to map UVs properly in 3ds max while baking if that's the issue.
Also, do I need to use any custom shaders to get such effects? (I honestly know nothing about shaders if this question seems silly)
Thanks in advance.
I would highly recommend using the THREEjs exporter:
https://github.com/mrdoob/three.js/tree/dev/utils/exporters/max
I have had a lot of trouble with Maya and other programs using any of the built in export options. Face winding, UVs and other stuff seems pretty iffy.The exporter helps.
Once you've done that, there's something else to keep in mind - THREEjs allows two sets of UVs only per piece of geometry. One for the map, bumpmap, displacementmap, etc, and another for the lightmap. So if those two UV sets end up different from one another, you might need to swap which you assign as map and which as lightmap.
Link a fiddle with what results you have so far and we might be able to help more. The only thing i can recommend is to use the THREEjs exporter without seeing what code you're using.
Exporter for 3ds Max has been dropped from the official Three.js repos, you should use glTF format instead. See this official page for the list of glTF-compatible Max exporters:
https://github.com/KhronosGroup/glTF
Using three.js am trying to create a floor that reflects the objects that sit upon it. Preferably the floor material should reflect not like a mirror but in a more 'matte' or diffused way.
To achieve this I looked to Jaume Sanchez Elias who has made a great example using a cube camera: Look for the "smooth material" example on this page:
http://www.clicktorelease.com/blog/making-of-cruciform
Here is my attempt using the same technique. But as you see the reflections are misplaced, they do not appear underneath the mountain objects as expected.
http://dev.udart.dk/stackoverflow_reflections/
I am looking to correct this or to use any other technique that will achieve a more correct diffused reflection.
There are three.js examples using the cube camera technique but they all create mirror-like effects not a soft reflection.
Vibber. Parallax-corrected cubemaps, the technique used in cru·ci·form, only works for closed volumes, like cubes. It works really well to simulate correct reflections inside a room, but not so much for outdoors or open/large scenes. They also can't reflect anything that it's inside the cubemap, you'd have to split the volume in many sub-volumes.
I can think of a couple of solutions for what you want to achieve:
SSR: Screen-space reflections, you can find more info in many places on the internet. It's not the most trivial of effects to implement, and you might have to change the way you render your scene.
Simpler post-processing approach: since you have a flat floor, render the mountains vertically flipped on a framebuffer object, blur it, and render the regular scene on top. For extra effect, render the depth of the flipped mountains, and use that value as the blur radius, to get diffuse reflections.
As always, there's a ton of ways to achieve the (un)expected result :)
Does Three.JS have a function or capability of AI( Artificial intelligence )? Specifically let's say a FPS game. I want enemies to look for me and try to kill me, is it possible in three.js? Do they have a functionality or a system of such?
Webgl
create buffer
bind buffer
allocate data
set up state
issue draw call
run GLSL shaders
three.js
create a 3d context using WebGL
create 3 dimensional objects
create a scene graph
create primitives like spheres, cubes, toruses
move objects around, rotate them scale them
test for intersections between rays, triangles, planes, spheres, etc.
create 'materials' (rather than shaders)
javascript
write algorithms
I want enemies to look for me and try to kill me
Yes, three.js is capable of doing this, you just have to write an algorithm using three's classes. Your enemies would be 3d objects, casting rays, intersecting with other objects, etc.
You would be building a game engine, and you could use three.js as your rendering framework within that engine. Rendering is just one part of it. Think of a 2d shooter, you could make it using a 2d context, but you could also enhance it and make it 2.5d, by working with a 3d context. Everything else can stay the same.
any webgl engine that might have it ? or is it just not a webgl thing
Unity probably has everything you can possibly think of. Unity is capable of outputting WebGL, so it could be considered a 'webgl engine'.
Bablyon.js is more engine like.
Three Js is the best and most powerfull WebGL 3d engine that has no equal on the market , and its missing out on such an ability
Three.js isn't exactly a 3d engine. Wikipedia says:
Three.js is a lightweight cross-browser JavaScript library/API used to
create and display animated 3D computer graphics on a Web browser.
Three.js uses WebGL.
so if i need to just draw a car, or a spinning logo, i don't need them to come looking for me, or try to shoot me. I just need them to stay in one place, and rotate.
For a graphics demo you don't even need this - with a few draw instructions, you could render a full screen quad with a very elaborate pixel shader. Three gives you a ton of options, especially if you consider all the featured examples.
It works both ways, while you can expand three.js anyway you want, you can strip it down for just a very specific purpose.
If you need to build an app that needs to do image processing, and feature no '3d' graphics, you could still leverage webgl with three.js.
You don't need any vector, matrix, ray , geometry classes.
If you don't have vector3, you probably cant keep planeGeometry, but you would use bufferGeometry, and manually construct a plane. No transformations need to happen, so no need for matrix classes. You'd use shaders, and textures, and perhaps something like the EffectsComposer.
I’m afraid not. Three.js is just a engine for displaying 3d content.
Using it to create games only is one possibility. However few websites raise with pre-coded stuff like AI (among other things) to attract game creators, but using them is more restrictive than writing the exact code you need
Three.js itself doesn't however https://mugen87.github.io/yuka/ is a great AI engine that can work in collaboration with three to create AI.
They do a line if sight and a shooting game logic, as well as car logic which I've been playing around with recently, a React Three Fiber example here: https://codesandbox.io/s/loving-tdd-u1fs9o
I create a THREE.PlaneGeometry with heights, in the highest point locate a THREE.PointLight, but this illuminates areas that are not seen from this point.
Why?
I want light from a point only the areas that are viewed from.
By default, the appearance of any given point on a surface is calculated using the lights, their properties and of course the material properties - it does not take the rest of the scene into account, as that would be very computationally expensive. Various ray tracing renderers do this, but they are really slow, and that's not how WebGL and Three.js work.
What you want is shadows. Three.js is capable of rendering shadows using Shadow Map method. There are various examples on using shadow maps both on the net and Three.js examples folder.
A word of warning though, getting shadows to work well can be hard if you don't have the basics down well - you may need to do some studying. Shadows can slow your application down (specially with many lighs) and look ugly if not properly configured and fine-tuned. Also I think shadow maps are only supported for SpotLight and DirectionalLight, PointLights are trickier.