Big Error: TVParticleSystem TV_EMITTERSHAPE_SPHERESURFACE does not work

[Shadowsong]

Sorry that I have to report this but it is clearly a Bug.

TV_EMITTERSHAPE_SPHERESURFACE does not work. In Fact it has the same effect as TV_EMITTERSHAPE_SPHEREVOLUME.

So basically, using Spheresurface does not make particles appear on a surface but instead makes them appear inside a sphere, which is what Spherevolume should do.
Strangely the problem does not happen with Boxsurface, that is just fine.

So to sum it up here is what happens:

TVParticleSystem.SetEmitterShape(X, TV_EMITTERSHAPE_SPHERESURFACE) => emits within volumetric sphere (WRONG)
TVParticleSystem.SetEmitterShape(X, TV_EMITTERSHAPE_SPHEREVOLUME) => emits within volumetric sphere (OK)
TVParticleSystem.SetEmitterShape(X, TV_EMITTERSHAPE_BOXSURFACE) => emits within flat rect. surface (OK)
TVParticleSystem.SetEmitterShape(X, TV_EMITTERSHAPE_BOXVOLUME) => emits within volumetric box (OK)

Of course I have checked to have set SetEmitterSphereRadius(...) correctly.

So Sylvain or anybody, can you confirm this bug? And yes, this also happens in the TV Particleeditor.
I would love to have this fixed, so ahm, is there any chance there'll be a fixed release anytime soon? Please give me an honest answer so I know if I can wait for the fix or have to work around this.

Thanks by a 4+ years user.

[SylvainTV]

Thanks, I will check this weekend. It shouldn't be very hard to fix !

[SylvainTV]

Well it works correctly here... I think it's working in your case too.

Do the experiment in the particle editor :

Create a particle system with standard properties
Set Emitter radius to 500
Set Emitter shape to sphere surface or sphere volume to test
Set max number of particles to 10000
Set emitter speed to 1

Rotate the camera with the keyboard arrows, you will see the difference between sphere volume and sphere surface.

So no bug there I think

[Shadowsong]

For the very first time I realized what those settings are supposed to do!
So from the beginning, it was a misunderstanding.
So ok, I get it, "surface" is meant to create the particles around the actual surface of either a box or a sphere.
Well what I was thinking all the time was, that "surface" meant "2d". So the effect I was expecting is the following:

- Set Shape to BoxSurface
- Set Box Size to 100/0/100

and see what happens. The particles are created on a 2-dimensional square. And THAT is what I want to have except with a circle! Do you understand that?

So it is no bug but rather a feature request. Would it be possible to add another shape-mode maybe called SHAPE_2D_CIRCLE which does what I descibed above?
I believe this is neccessary for a lot of particle effects and I really need it. The virtual 2d-circle would simply be aligned to the world XZ-plane and would have a specific radius. The particles would spawn within this circle with random x and z values but with a constant y value (which would be the y of the emitter's position). You could use the SphereRadius variable here as well.

So sorry, I hope you understand my confusion and I hope you can help me!
Thanks in advance Sylvain!

Box Surface:


2d-circle:

[Mithrandir]

I would suggest changing the sphere to ellipsoid with X, Y, Z dimensions. Then you can use the same trick as with the box plus you'll have an ellipsoid for free

[Shadowsong]

Hm I would think such an ellipsoid calculation would eat up a lot of performance. While a simple 2d cirle should be very simple and fast.