What would be the best way to implement ambient sound for a (curvi)linear spatial in 3D?
In my case, I'm trying to implement riverflow sound along a river. If there's not a more elegant and easier way, I will choose the hard way and move the audio source (AudioStreamPlayer3D) along the river (somehow snapped to the river baseline).
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There are some 3D applications which can cast shadow or silhouette below 3D models. They render pretty fast and smooth. I wonder what kind of technology is the standard procedure to get 3D model shadow/silhouette.
For example is there any C++ library like libigl or CGAL to get shadow/silhouette pretty fast? Or maybe GLSL shading is used? Any hint would be appreciated on the standard technology stack.
For rendering, it's trivial. Just project the vertices to the surface (for the case of the XY plane, this just entails setting the Z coordinate to 0) and render the triangles. There'll be a lot of overlap, but since you're just rendering that won't matter.
If you're trying to build a set of polygons representing the silhouette shape, you'll need to instead union the projected triangles using something like the Vatti clipping algorithm.
Computing shadows is a vast and uneasy topic. In the real world, light sources are extended and the shadow edges are not sharp (there is penumbra). Then there are cast shadows, and even self-shadows.
If you limit yourself to punctual light sources (hence sharp shadows), there is a simple principle: if you place an observer at the light source, the faces he will see are illuminated by that light source. Conversely, the hidden surfaces are in the shadow.
For correct rendering, the shadowed areas should be back-projected to the scene and painted black.
By nature, the ray-tracing techniques make this process easy to implement.
I'm trying to make my sound effects work as in 3D environment in a 2D platformer game.
The problem is that when I set Spatial Blend option to 3D on my sound effects it gets really quiet but if I keep it on 2D it will play at the same volume through-out the entire room.
All of the answers to this problem recommend keeping the Spatial Blend option on 2d but I actually want to hear the sound effect at different volume levels depending on where the camera/character is.
May be change curve distance volume?
I have a 3d vector for a listener position and a 3d vector for a sound source. I also have a 3d vector for the orientation of the listener. I am trying to find the NED (north, east, down) for the position of the source relative to the listener so I can play the sounds in the right speakers... I've made so research but I can't seem to find the necessary equations...
Any idea?
Thanks!
The Ambisonics B-Format codec does what exactly what you're describing. However, although the specification of this codec is open, finding it is rather challenging due to it's unfortunate unpopularity.
The good news is, I've written a BSD open-source project called "Ambisonix" that details all the equations required to achieve up to 3rd order Ambisonics encoding and decoding. I've also added on some features such as distance encoding and Doppler effect which are not part of the original spec.
Check it out at: http://sourceforge.net/projects/ambisonix
I don't think you're going to find exactly what you're looking for. Spatial location of sound sources in a 3D field is a very complex subject and depends on many factors (listener location, loudspeaker locations, source material). The closest to what you're describing is probably Ambisonics, but this needs the listening setup to be Ambisonics too, which is not very common. If you're using something like Dolby Digital, I don't think they give out the equations, you need to license the algorithms or mix the source material with equipment which has the algorithms licensed and built in. However, systems such as Dolby are not really designed for precise sound source location in a 3D field - they're really just a spatial effect which gives the listener the feeling of a 3D sound field.
You need to subtract listener vector from sound vector then you can rotate through listener orientation vector. Now you can simple check if new vector is positive or negative on axes. For example vector [ 0, 10, -2] can be read as [0,+,-] and it means [central, up, back]. To use N-S W-E U-D directions just don't rotate vector after subtract.
As a brief background, I have been slowly chugging away at the core framework of a game I've been wanting to make for some time now. It has gotten to the point where I want to start really fleshing it out with some graphics assets other than colored boxes. And this brings me to the heart of my question:
What is the best method for creating graphics assets that appear the same quality independent of the device they are drawn on?
My game is styled after Pokemon, so I want to capture the 16-bit feel while still remaining crisp regardless of the device resolution. Does this mean I just create a ton of duplicate sprite sheets? i.e. a 16x16 32x32 48x48 64x64 version of each asset? Or should I be making vector art and rendering it out specifically for each device? Or is there some other alternative I haven't considered?
Thanks!
If by 16-bit feel you mean a classic old-school "pixelated" style (but with crisp edges). Then you can just draw them in the minimal dimension and upscale by whatever factor you need using a Pixel Art Scaling Algorithm, the simplest being nearest neighbour. There are of course many algos that produce much nicer results than NN like the 2xSaI and hqx family of algorithms, and RotSprite if you need rotation.
If you want clean antialiased edges you might want to check out this Microsoft Research paper: Depixelizing Pixel Art
You can then use these algos as a loading pre-pass for your game.
Alternatively, you could shift them "earlier" into your art pipeline to help speed up generation of multiple (resolution/transform) variants, which you could further touch up. This choice largely depends on your level of labor resources and perfectionism. Note also that this loses the "purity" of the solution since it violates DRY because updates will require changes in all variants of a sprite.
I would suggest to first try out some of these upscaling filters and see if you are happy with the results. If you are, you can get away with a loading prepass, which is by far the most desirable outcome because it reduces work and maintenance by a large factor.
I have a black and white 2D drawing of a silhouette (say, a chess piece) that I would like to rotate around an axis to create a 3D object.
Then I want to render that 3D object from multiple angles using some sort of raytracing software, saving each angle into a separate file.
What would be the easiest way to automatically (repeatedly) 1. get a vector path from the 2d drawing 2. create the 3D model by rotating it 3. import it into the raytracer.
I haven't chosen a specific raytracer yet, but Sunflow has caught my eye.
Texturing/bump mapping would be nice but non-essential
The modeling feature you're looking for is a Lathe.
Sunflow can import 3ds files and blender files.
I've never used blender, but here's a tutorial for using the lathe to make a wine glass. You'd replace the silhouette of the wine glass with your shape:
http://www.blendermagz.com/2009/04/14/blender-3d-lathe-modeling-wine-glass/
Blender is FOSS, you can down load it here:
www.blender.org/download/get-blender/ (can't post more than one link, so you'll have to type this one in yourself :-)
I found a pretty cool site where you can do this online, interactively:
http://www.fi.uu.nl/toepassingen/00182/toepassing_wisweb.en.html
No great detail revolution but maybe you can find the code and extend it to your needs.