I am using THREE.MeshLine from https://github.com/spite/THREE.MeshLine to try and draw lines in three.js. The lines appear to work when using a perspective camera to view the scene as the demos showed, but when I use an orthographic camera which is the camera I need to use for my project, the line is distorted.
For now, I am trying to make sure that the line works by creating a sin wave, but with the ortho camera, it looks like this:
Why does the mesh not display correctly with an orthographic camera? Are there any ways to fix this or achieve orthographic lines with a thickness in three.js?
This is a know issue, see https://github.com/spite/THREE.MeshLine/issues/118.
The wide line implementation of three.js does support orthographic cameras, though.
Related
I want to render a cube similar to .
My problem is how to render the face projections.
I tried using Reflector, but it is tricky to size and position so it captures just the face that I want, and also shows the sides.
I also saw I can use a separate canvas to render (I imagine using an orthographic camera), but I wish for everything to be in the same canvas. I saw an example with multiple views, but it seems that they can't be positioned behind.
So, is there a way to achieve this?
One possible approach to solve the issue:
Setup an orthographic camera such that its frustum encloses the cube. You can then position the camera in front of each side of the cube, use lookAt( cube.position ) to orient it properly and then render the scene into a render target. You need one render target per side. You can then use it as a texture for the respective plane mesh.
There is an official live example that demonstrates how RTT (render-to-texture) is done with three.js. Try to use it as a code template for your own app.
https://threejs.org/examples/#webgl_rtt
Does anyone have any suggestion of how to implement such a light glow effect in Three.js ?
There is a TextGeometry mesh
Some BoxGeometry mesh as a background
How to make this glow between them?
I tried to put many PointLight between text and box, but after about 20 of PointLights the scene become very slow. I tried to put some RectAreaLights — but the same.
Does anyone have any suggestion of how to implement such a light glow effect in Three.js ?
The typical way of doing this is via post-processing. three.js offers a so called "Bloom" pass which is demonstrated in the following example: webgl_postprocessing_unreal_bloom. I suggest you start with this setup.
but after about 20 of PointLights the scene become very slow. I tried to put some RectAreaLights — but the same.
It's no good approach in general to add that number of light sources to a three.js scene. If you place some small sphere meshes (based on THREE.SphereGeometry) with a bright material color onto the text, you should get a good result with bloom pass.
I used sprites in Three js to display 2d images, the problem that I faced with sprites that they rotate to face the camera.
I am trying to use it to fake a shadow for the 3d object. When I rotate the camera the 3d object tilt with the camera until it makes a 30-degree angle with the horizontal but it's shadow (2d sprite) still at 0 degrees.
How to disable the auto rotation of sprite, or is there another solution to preview 2d images in three js to look like a 3d object?
How to disable the auto rotation of sprite, or is there another solution to preview 2d images in three js to look like a 3d object?
It's not possible to disable the orientation towards the camera with a flag or configuration. You would have to modify the shader code of SpriteMaterial for this.
I suggest you use a mesh instead based on a PlaneBufferGeometry and a MeshBasicMaterial. Alternatively, you write a custom billboard shader with ShaderMaterial or RawShaderMaterial.
I'm trying to create a shadow in my orthographic scene in three.js. I'd like to have a directional light so the shadow is offset from all objects equally in the scene. I am however having problems using DirectionalLight.
My first problem is that I can't get the shado to cover the entire scene, only part of it ever has a shadow. I played with the light's frustum settings, but can't figure out how to get it to cover the scene. Ideally I'd want the frustrum to match that of the camera.
The second problem is that the shadows aren't "clean". If I use a SpotLight the shadows have nice crisp borders (but obviously not the universal directionality I want). When I use a DirectionalLight the borders are misshappen and blurry.
In the samples the tile is a simply box created with CubeGeometry.
How can I create an ortographic directional light source for my scene?
How do I create a three.js material/geometry which uses part of a texture?
I am first rendering a scene to a texture. This texture is used for a Mesh with a CubeGeometry and a MeshLambertMaterial. What I would like to do now is have only a part of the texture displayed on the cube face (like a window into the texture).
I've done this before using OpenGL ES directly, with shaders, but I don't see what parameters might make it possible using the standard three.js library.
That is what texture coordinates are for. See this question and answer:
http://stackoverflow.com/questions/19366991/drawing-part-of-open-gl-texture/19367844#19367844