skeeto / webgl-particles

WebGL particle system demo

WebGL Particle System Demo

• Online Demo
• A GPU Approach to Particle Physics

webgl-particles's Issues

Particle Drift on Mobile

It seems like the particles drift left and upwards on mobile devices (both android and ios). I'm wondering if this is caused by the browser scaling the gl viewport to compensate for high dpi screens? You can see the effect by viewing the demo on any mobile device. I tried on a Samsung Galaxy S6 and iPhone 6S.

Any other ideas as to why this might be happening? Could there be a loss of precision or some kind of rounding error going on?

I checked and both devices have 16 slots for textures in the vertex shader with:

var vertexUnits = gl.getParameter(gl.MAX_VERTEX_TEXTURE_IMAGE_UNITS);

FWIW window.devicePixelRatio is 4 on my Android and 3 on my iPhone.

Thanks!

Simulating 0 particles causes a crash

Hello. I noticed that pressing Fewer until 0 particles are simulated causes the simulation to crash with the errors:

WebGL: INVALID_FRAMEBUFFER_OPERATION: drawArrays: attachment has a 0 dimension
Uncaught Error: WebGL rendering error

This can probably be fixed by preventing the number of simulated particles from going below 1.

How to make this lib support image ?

I'm a newbie of shader. (and with bad English, sorry)
Could you give me some advices ?
I want to use image as particles.
（ do something like this :　http://www.goodboydigital.com/pixijs/bunnymark_v3/　）
All particles use the same image file , but use different parts of the image. (like sprite-sheet)

Thanks.

Question :)

@skeeto Hi :)
I'm glad to see your codes.
And I have a couple of question. In https://github.com/skeeto/webgl-particles/blob/master/js/particles.js#L15, What does mean in dividing by 3 ? and In https://github.com/skeeto/webgl-particles/blob/master/js/particles.js#L16, Why did you multiply 100 to channel1's(?) scale?
Thank you :)