Inside my scene I have a THREE.Line with THREE.LineBasicMaterial next to many other objects. I want to render that line through every other object, like they are transparent for it.
I tried to use .renderDepth but it doesn't seem to do anything in that regard.
The approach I would use now is projecting the line onto a plane right infront of the camera. But that is rather complex and inefficient. Are there any simple solutions?
Related
I've built a basic scene for SceneKit, including several SCNNodes with geometries, SCNLights, and an SCNCamera. I would now like to add functionality whereby the point of view shifts between different camera positions when the user taps on the screen.
What is the best way to achieve this? Should I include several SCNCameras in the scene and switch sceneView.pointOfView between them? Or should I rather update the position (and orientation) of a single camera. Also, how can I specify the transition path from moving from the old to the new camera position, i.e. use animation for the transition.
changing the pointOfView of the view is the easiest way. But if you want to control the path you will have to move the camera yourself. You can do that with SCNAction or by using CoreAnimation explicit or implicit animations.
I'd like to create some mechanism that provides a text overlay on top of my 3D scene at certain times (such as when clicking a mouse button for instance.)
I'm going over the tutorials on github and notice things like the THREE.TextGeometry class. Using it I can put 3D text in the scene, but it may be a bit more than I need-- what I'm really after is a way to put some text on, say, a black background, overlay it on the scene, then move it out of the way when done. Does anyone know of good ways to do this in three.js? (If the THREE.TextGeometry class is a good way to do this that's fine, I'm just not sure how to do the overlay bit.)
Use HTML. It's super easy and powerful especially if you just need an overlay. With CSS, you can also achieve things like semi-transparent background. If you want to have it "blend" to scene, i.e. have perspective etc. you can use THREE.CSS3DRenderer which will transform divs based on camera you supply.
i need some help in my webGL code.
I created a TextGeometry and i included it in a mesh, i didn't have any problem about that. However, i would like updating this text without creating another TextGeometry.
Indeed, my main goal is to translate a text (from right to left) and to make it disappear when he reaches to the left side, but only character by character (like a fade effect).
I tried some attempts : for example, according to text position, deleting it with a :
scene.remove(text)
and creating another text which is the same as previously minus the first character. I don't know if i was clear... But this solution makes my application very slow : that's why i don't want creating an Object every time, but just updating his text property.
I didn't find many help in three.js documentation, may you give me a hand about that ?
Cheers
You could try this:
Create a PlaneGeometry and texture it using the image from a hidden canvas object that contains your text, then apply image transforms to the canvas itself (fading as necessary) and continually update the texture in Three.js as it moves across the scene.
For an example of how to use a canvas object as an image (of text), I have an example posted at: http://stemkoski.github.com/Three.js/Texture-From-Canvas.html
I am trying to create a cube using three.js for a project. I need to add text to vertices and at different points inside the cube. Any idea how this can be done?
For some basic code examples of using Sprite objects in Three.js, check out:
http://stemkoski.github.com/Three.js/Sprites.html
And for an easy way to create images that contain text to use as your sprite textures, check out the sample code at:
http://stemkoski.github.com/Three.js/Texture-From-Canvas.html
I think a combination of these two ideas will achieve what you are looking to do.
If you want to have label-style texts, so that the text begins at a specific point, but is always oriented with the camera and easily readable no matter the camera position, you can use sprites. (example of canvas-created text label sprites: http://i.imgur.com/e9I68xD.jpg - here they are rendered on a separate pass to that they are never obscured by the scene but you can do it on the same pass)
If that's what you are looking for, I'd suggest first checking the Sprites examples, and learn to attach some static image as a sprite to correct position in the scene. After you get that working, you modify the code so that you generate the text to an image canvas using standard Javascript Canvas functions, and using that image as the sprite.
I have a question...
Is it possible to disable the GL10.GL_DEPTH_TEST for only one Object?
In my example a have a Groundplane, with a Alphashadow Texture and I want to disable
the DEPTH_TEST for my Carmodel, to fake shadows. The other Objects should't have the DEPTH_TEST Disabled, so I wouldn't see the shadows through them.
Here is a Screenshot (the shadows aren't perfecty translated to their objects, but I think you will get my problem) https://dl.dropbox.com/u/18265107/special/screenshot.png
Anything you disable depth-test for will show on top of other stuff. You can choose to do, or not do, that for anything you like. However I don't think it will fix your shadows.
To achieve what you were wanting, disabling depth-test isn't enough, and you would need to render things in the right order:
render the ground.
render the car.
render the shadows, with depth-test disabled.
render the rest of the environment.
However this assumes the ground is flat, and that shadows don't cast onto other scene objects, which will probably look wrong.