Masa

I am exploring particle system with jit.p.shiva and jit.p.vishnu, and wondering how I could change the size of each point particle.

I am exploring particle system with jit.p.shiva and jit.p.vishnu, and wondering how I could change the size of each point particle.
I would appreciate your advice.

how-to-change-the-size-of-each-point-particle-jit-p-shiva-particle-system

depends on what you're using to draw your particles. the jit.p.* objects simply output matrices, those matrices can be used in many different ways to draw things. need to see your patch.

Thanks Rob again. Here's the patch. Please look at the area with a orange panel.

*The file has been updated and the download URL has been changed, please see my reply below

Thanks Rob again. Here's the patch. Please look at the area with a orange panel.
*The file has been updated and the download URL has been changed, please see my reply below


I'm also wondering about this. From the jit.p.shiva help patch and documentation I'm assuming that you need to use additional planes in the matrix to store this extra information. Particle size in your case, Masa (probably three floats for scale?) - colour information in mine (four floats for argb?).

What I don't understand is how to make use of that extra information once it's in the matrix? If I understand it correctly, jit.p.shiva seems to inherently know that planes 0 and 1 are ID and age respectively, and that planes 2, 3 and 4 are xyz position data, but how do I tell jit.p.shiva that planes 5, 6, 7, and 8 is argb information (or xyz scale in Masa's case)? Am I on the right track?

I'm also wondering about this. From the jit.p.shiva help patch and documentation I'm assuming that you need to use additional planes in the matrix to store this extra information. Particle size in your case, Masa (probably three floats for scale?) - colour information in mine (four floats for argb?). 

OK so I made some progress on my situation yesterday - figured that using extra planes to store other information such as scale or colour seems to be incompatible with jit.p.vishnu which expects only 5 or 8-plane matrices. Am I correct in saying that?

So, I've switched from using jit.p.vishnu to just using jit.p.shiva in mode 1 and modifying the position of the particles by manually manipulating the matrices as per the 'More Information' tab of the help file. Now I'm able to store the extra colour information in the matrices that can be read by the jit.gl.multiple object that I'm using to render the particles, but now I've got the problem that I can't figure out how to set the colours stored in the matrices dynamically.

The effect I'm going for is that the colour of the newest emitted particle is set by the x position of the emitter.

Have now attached my patch - any help greatly appreciated!

P.S. Sorry for hi-jacking the thread Masa, but I'm pretty sure that the solutions to our problems will be identical.

if you want particle geometry to change size when it moves closer to the camera, you can't use points do draw them, and instead must use something like gl.multiple with gl.gridshape. points have no size, they're simply points, and therefore will look the same regardless of their proximity to the camera.

if  you want particle geometry to change size when it moves closer to the camera, you can't use points do draw them, and instead must use something like gl.multiple with gl.gridshape. points have no size, they're simply points, and therefore will look the same regardless of their proximity to the camera.


Thank you very much again Rob. OK, 'points have no size'. Then need to find another way to build particle systems.

Here's the updated patch for people who come across this thread.

https://dl.dropboxusercontent.com/u/8000923/max_forum/Time.zip

I put red-coloured panels to relevant areas.

If you can't open the patch smoothly, please try the following steps (this is another problem I have to solve).

1. Open the patch with disabling loadbang and loadmess (Cmd+Shift)

Here's the updated patch for people who come across this thread.https://dl.dropboxusercontent.com/u/8000923/max_forum/Time.zip
I put red-coloured panels to relevant areas.

If you can't open the patch smoothly, please try the following steps (this is another problem I have to solve).
1. Open the patch with disabling loadbang and loadmess (Cmd+Shift)
2. Close the patch
3. Open the patch again normally

How to change the size of each point particle? (jit.p.shiva particle system)