Parallax effect using three.js - javascript

I would like to build a parallax effect from a 2D image using a depth map, similar to this, or this but using three.js.
Question is, where should I start with? Using just a PlaneGeometry with a MeshStandardMaterial renders my 2D image without parallax occlusion. Once I add my depth map as displacementMap property I can see some sort of displacement, but it is very low-res. (Maybe, since displacement maps are not meant to be used for this?)
My first attempt
import * as THREE from "three";
import image from "./Resources/Images/image.jpg";
import depth from "./Resources/Images/depth.jpg";
[...]
const geometry = new THREE.PlaneGeometry(200, 200, 10, 10);
const material = new THREE.MeshStandardMaterial();
const spriteMap = new THREE.TextureLoader().load(image);
const depthMap = new THREE.TextureLoader().load(depth);
material.map = spriteMap;
material.displacementMap = depthMap;
material.displacementScale = 20;
const plane = new THREE.Mesh(geometry, material);
Or should I use a Sprite object, which face always points to the camera? But how to apply the depth map to it then?
I've set up a codesandbox with what I've got so far. It also contains event listener for mouse movement and rotates the camera on movement as it is work in progress.
Update 1
So I figured out, that I seem to need a custom ShaderMaterial for this. After looking at pixijs's implementation I've found out, that it is based on a custom shader.
Since I have access to the source, all I need to do is rewrite it to be compatible with threejs. But the big question is: HOW
Would be awesome if someone could point me into the right direction, thanks!

Related

Three.JS: render a large map based on different tilesets (Texture Atlas)

Introduction:
I render an isometric map with Three.JS (v95, WebGL Renderer). The map includes many different graphic tilesets. I get the specific tile via a TextureAtlasLoader and it’s position from a JSON. It looks like this:
The problem is that it performs really slow the more tiles I render (I need to render about 120’000 tiles on one map). I can barely move the camera then. I know there are several better approaches than adding every single tile as sprite to the scene. But I’m stuck somehow.
Current extract from the code to create the tiles (it’s in a loop):
var ts_tile = Map.Imagesets[ims].Map.getTexture((bg_left / tw), (bg_top / th));
var material = new THREE.SpriteMaterial({ map: ts_tile, color: 0xffffff, fog: false });
var sprite = new THREE.Sprite(material);
sprite.position.set(pos_left, -top, 0);
sprite.scale.set(tw, th, 1);
scene.add(sprite)
I also tried to render it as a Mesh, which also works, but the performance is the same (of course):
var material = new THREE.MeshBasicMaterial({ map: ts_tile, color: 0xffffff, transparent: true, depthWrite: false });
var geo = new THREE.PlaneGeometry(1, 1, 1);
var sprite = new THREE.Mesh(new THREE.BufferGeometry().fromGeometry(geo), material);
possible solutions in the web:
I know that I can’t add so many sprites or meshes to a scene and I have tried different things and looked at examples, where it works flawless, but I can’t adapt their approaches to my code. Every tile on my map has a different texture and has it’s own position.
There is an example in the official three.js docs: They work with PointsMaterial and Points. In the end they only add 5 Points to the scene, which includes about 10000 “vertices / Images”. docs: https://threejs.org/examples/#webgl_points_sprites
Another approach can be found here on github: https://github.com/YaleDHLab/pix-plot
They create 5 meshes, every mesh includes around 4096 “tiles”, which they build up with Faces, Vertices, etc.
Final question:
My question is, how can I render my map more performant? I’m simply overchallenged by changing my code into one of the possible solutions.
I think Sergiu Paraschiv is on the right track. Try to split your rendering into chunks. This strategy and others are outlined here: Tilemap Performance. Depending on how dynamic your terrain is, these chunks could be bigger or smaller. This way you only have to re-render chunks that have changed. Assuming your terrain doesn't change, you can render the whole terrain to a texture and then you only have to render a single texture per frame, rather than a huge array of them. Take a look at this tutorial on rendering to a texture, it should give you an idea on where to start with rendering your chunks.

Apply three.js subdivision modifier without changing outer geometry?

I am trying to take any three.js geometry and subdivide its existing faces into smaller faces. This would essentially give the geometry a higher "resolution". There is a subdivision modifier tool in the examples of three.js that works great for what I'm trying to do, but it ends up changing and morphing the original shape of the geometry. I'd like to retain the original shape.
View the Subdivision Modifier Example
Example of how the current subdivision modifier behaves:
Rough example of how I'd like it to behave:
The subdivision modifier is applied like this:
let originalGeometry = new THREE.BoxGeometry(1, 1, 1);
let subdivisionModifier = new THREE.SubdivisionModifier(3);
let subdividedGeometry = originalGeometry.clone();
subdivisionModifier.modify(subdividedGeometry);
I attempted to dig around the source of the subdivision modifier, but I wasn't sure how to modify it to get the desired result.
Note: The subdivision should be able to be applied to any geometry. My example of the desired result might make it seem that a three.js PlaneGeometry with increased segments would work, but I need this to be applied to a variety of geometries.
Based on the suggestions in the comments by TheJim01, I was able to dig through the original source and modify the vertex weight, edge weight, and beta values to retain the original shape. My modifications should remove any averaging, and put all the weight toward the source shape.
There were three sections that had to be modified, so I went ahead and made it an option that can be passed into the constructor called retainShape, which defaults to false.
I made a gist with the modified code for SubdivisionGeometry.js.
View the modified SubdivisionGeometry.js Gist
Below is an example of a cube being subdivided with the option turned off, and turned on.
Left: new THREE.SubdivisionModifier(2, false);
Right: new THREE.SubdivisionModifier(2, true);
If anyone runs into any issues with this or has any questions, let me know!
The current version of three.js has optional parameters for PlaneGeometry that specify the number of segments for the width and height; both default to 1. In the example below I set both widthSegments and heightSegments to 128. This has a similar effect as using SubdivisionModifier. In fact, SubdivisionModifier distorts the shape, but specifying the segments does not distort the shape and works better for me.
var widthSegments = 128;
var heightSegments = 128;
var geometry = new THREE.PlaneGeometry(10, 10, widthSegments, heightSegments);
// var geometry = new THREE.PlaneGeoemtry(10,10); // segments default to 1
// var modifier = new THREE.SubdivisionModifier( 7 );
// geometry = modifier.modify(geometry);
https://threejs.org/docs/#api/en/geometries/PlaneGeometry

Three.js - setting cube color?

I am trying to create a simple 3d game with three.js. I am trying to create coloured cubes, but all the cubes just stay the same color.
When I create a cube I do:
var geometry = new THREE.BoxGeometry(width, height, length);
var material = new THREE.MeshNormalMaterial({color: hexColor});
var cube = new THREE.Mesh(geometry, material);
(which is inside a function)
Then I use the function twice,
hexColor being 0x0000ff(blue) and 0xff0000(red).
The cubes do generate, but all the faces of the cubes are different colours.
I have also tried
cube.material.color.setHex();
But it gives out Uncaught TypeError: Cannot read property 'setHex' of undefined
Help please!!
your issue is that THREE.MeshNormalMaterial() doesn't have a color property. Try using THREE.MeshBasicMaterial({ color: yourHexColor }); instead.
If you do that, your cube.material.color.setHex(yourHexColor); call should work just fine.
You can find all of the necessary information on the Three.js docs page and, if you're interested, take a look at the dedicated examples page.

BabylonJS Radial vs Rectangular Textures (Conversion or Code Change)

I am working with the planetary textures from this site. They are all in rectangular form.
However, in my BabylonJS application, textures are expected to be like this.
I have tried setting the coordinates mode, but it doesn't seem to do anything.
// These didn't have an effect
material.diffuseTexture.coordinatesMode = BABYLON.Texture.SPHERICAL_MODE;
material.diffuseTexture.coordinatesMode = BABYLON.Texture.EXPLICIT_MODE;
material.diffuseTexture.coordinatesMode = BABYLON.Texture.SPHERICAL_MODE;
material.diffuseTexture.coordinatesMode = BABYLON.Texture.PLANAR_MODE;
material.diffuseTexture.coordinatesMode = BABYLON.Texture.CUBIC_MODE;
material.diffuseTexture.coordinatesMode = BABYLON.Texture.PROJECTION_MODE;
material.diffuseTexture.coordinatesMode = BABYLON.Texture.SKYBOX_MODE;
Is there a way to convert between these two kinds of textures? Alternatively, are their planet textures like the bottom.
In fact this is related to the texture coordinates embedded into your mesh. You should use Blender to export different coordinates or you can also play with texture.uOffset, texture.vOffset, texture.uScale and texture.vScale to move your texture on your mesh

Babylon.js Mesh Picking & Ignoring Some Meshes

I am currently working on a small project using the new Babylon.js framework. One of the issues I have run into is that I basically have two meshes. One of the meshes is supposed to be the background, and the other is supposed to follow the cursor to mark where on the other mesh you are targeting. The problem is that when I move the targeting mesh to the position of the cursor, it blocks the background mesh when I use scene.pick, resulting in the other mesh having its position set on its self.
Is there any way to ignore the targeting mesh when using scene.pick so that I only pick the background mesh or is there some other method I could use? If not, what would be the steps to implement this sort of feature to essentially raycast only through certain meshes?
If you need code samples or any other forms of description, let me know. Thanks!
Ok, it's easy.
So, we have two meshes. One is called "ground", the second "cursor". If you want to pick only on the ground you have two solutions :
First:
var ground = new BABYLON.Mesh("ground",scene);
ground.isPickable = true ;
var cursor = new BABYLON.Mesh("cursor", scene);
cursor.isPickable = false;
...
var p = scene.pick(event.clientX, event.clientY); // it return only "isPickable" meshes
...
Second:
var ground = new BABYLON.Mesh("ground",scene);
var cursor = new BABYLON.Mesh("cursor", scene);
...
var p = scene.pick(event.clientX, event.clientY, function(mesh) {
return mesh.name == "ground"; // so only ground will be pickable
});
...
regards.

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