I am using threejs in a project where I need to keep a basic object in my scene just in front of the camera, whichever way the camera is pointed. I am using the Orbit Controls plugin for movement and want to move the object around the scene so it is always in the middle of the camera view (same distance away all the time).
I am a relative newcomer to threejs so am not sure how to approach this - thoughts would be appreciated!
Before rendering your scene, you need to update the position of your object by placing it in front of the camera, for that you can use camera.position and camera.getWorldDirection(), then do the math to compute what should be the position of your object.
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I'm using a Perspective Camera for my top down Three.js game, but it curves a bit too much because it's designed to be used as "first person view". Is there a way to adjust how much objects bend/curve in the frustum from the sides?
Essentially, I would like something like a mix of a Perspective Camera and an Orthographic Camera
E.g -- The walls of the buildings should be less visible from a certain distance
You can adjust the camera FOV.
https://threejs.org/docs/?q=persp#api/en/cameras/PerspectiveCamera
Made a simple Pen here:
https://codepen.io/cdeep/pen/eYEOqrz
camera.fov = 30;
camera.updateProjectionMatrix ();
The lesser the FOV, the more flatter things look.
Please note that you'll need to position the camera farther away at lower FOVs to ensure the contents fit inside the view which also requires you to increase the camera's far property so things don't get cut out
I'm kinda new in Three js and I've been struggling with this for a while.
I have a 3d model facing a certain direction.
There is also a sphere around it and before moving the mesh, I want to animate it's rotation so it will face specified sphere.
So far I managed to get the angle of rotation but I suppose that is not the way to go
this is what I use for rotating the object towards a specified point:
if(movementTarget) { playerModel.lookAt(movementTarget); }
and this is the content of the
movementTarget = {x:154,y:55,z:35};
seems like the model is not actually orienting towards the sphere, but an empty spot, not sure what is the issue
I have managed to solve the issue, the coordinate system had a general variable which amplified the distance between the objects, by calling lookAt() function, the camera was oriented in the correct direction, but since the corrdinates Were not multiplied since they came straight from the server.
I'm trying to make a sort of "lottery ball" simulator.
I'm having difficulty adding an object inside an object with physijis.
Physics work when I add the sphere to the scene, but when I add the child spheres to the main "lottery" sphere, it loses the physics.
If anyone could help, that would be great.
Thanks
I have a ParticleSystem and am trying to work out which particles are currently in front of the camera - ie in the frustum.
While I've had a look at frustum.js which has a handy function for determining if an object is in the frustum what's the method to determine if a single vertex is?
How do you make a mini-cam or mini-map using three.js?
Two camera views. One mini-map "mini-cam" - top right corner (see image below), and the main camera view should span the rest of the scene (the rest, without the border in image below).
N.B. This actually can't quite be done via the viewport method, as the scene shouldn't be cropped off by the x-dimensionality, but should stretch out.
I have created a working example of a scene together with a minimap at:
http://stemkoski.github.io/Three.js/Viewports-Minimap.html
I don't understand your N.B. about not able to be done using viewports; as you'll see in the code at the website posted above, if you use for example an orthogonal camera positioned above the scene, you can set the left/right/top/bottom values so that the entire scene is included in your render, you just have to be careful about the height-to-width ratio so that your scene doesn't appear stretched.
On the other hand, if you're looking to go to the render-to-texture route, I have a relevant example at http://stemkoski.github.io/Three.js/Camera-Texture.html but as yaku mentioned in his response, you will have to update the position of the plane mesh so that it follows both the camera position (offset by some amount) and also rotation so that it always faces the camera. Due to the more complex nature of this approach, I really recommend the viewport method.
You can make a plane geometry (normal 3D object, and it actually doesn't need to be a plane, any shape goes) representing the minimap, and add it to camera so it follows the camera movement and is always visible.
Then use "Render to Texture" method to render the minimap and slap the texture to the plane "container".
There are render to texture examples around the net, SO, as well as in the Three.js examples folder, those should help get you started with that.