Get the (standard) particles information

Helper

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On 04/10/2012 at 08:57, xxxxxxxx wrote:

I think this post might be of interest: https://developers.maxon.net/forum/topic/5919/6005_tparticle-data-not-available-in-python&PID=26813#26813

Helper

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On 04/10/2012 at 09:23, xxxxxxxx wrote:

That solution only works if there are objects as childs of the emitter and the "Show Objects" option is on.
I want to be able to access the particle values even if there are no objects being created.
And the good news are... I DID IT!!!
Check out the code:

  
import c4d   
import struct   
  
# return the number of active particles   
def P_count(buffer) :   
    count=0   
    for i in range(len(buffer)/88) :   
        index=i*88   
        bits=int(struct.unpack("B",buffer[index+80:index+81])[0])   
        count+=(bits!=0)   
    return count   
  
# return the ALIVE value of the particle p (0 or 1)   
def P_alive(p,buffer) :   
    index=p*88   
    bits=int(struct.unpack("B",buffer[index+80:index+81])[0])   
    return (bits & 2) >> 1   
  
# return the VISIBLE value of the particle p (0 or 1)   
def P_visible(p,buffer) :   
    index=p*88   
    bits=int(struct.unpack("B",buffer[index+80:index+81])[0])   
    return (bits & 1)   
  
# returns the vector of the current position of particle p   
def P_position(p,buffer) :   
    index=p*88   
    return c4d.Vector(struct.unpack("d",buffer[index:index+8])[0],struct.unpack("d",buffer[index+8:index+16])[0],struct.unpack("d",buffer[index+16:index+24])[0])   
  
# returns the vector of the current direction of particle p   
def P_direction(p,buffer) :   
    index=p*88   
    return c4d.Vector(struct.unpack("d",buffer[index+24:index+32])[0],struct.unpack("d",buffer[index+32:index+40])[0],struct.unpack("d",buffer[index+40:index+48])[0])   
  
# returns the vector of the current wing of particle p   
def P_wing(p,buffer) :   
    index=p*88   
    return c4d.Vector(struct.unpack("d",buffer[index+48:index+56])[0],struct.unpack("d",buffer[index+56:index+64])[0],struct.unpack("d",buffer[index+64:index+72])[0])   
  
# returns the life of particle p (double)   
def P_lifetime(p,buffer) :   
    index=p*88   
    return struct.unpack("d",buffer[index+72:index+80])   
  
def main() :   
    emitter=op.GetObject()   
    p_tag=emitter.GetTag(c4d.Tparticle)   
    if p_tag is None: return   
       
    buffer=p_tag.GetLowlevelDataAddressW()   
       
    count=P_count(buffer) # gets the number of active particles   
       
    for i in range(count) :   
        print "Particle "+str(i)     # print the particle number   
        print P_alive(i,buffer)          # print the active state of the particle   
        print P_visible(i,buffer)     # print the visibility of the particle   
        print P_position(i,buffer)     # print the current position of the particle   
        print P_direction(i,buffer)     # print the current direction of the particle   
        print P_wing(i,buffer)          # print the current wing of the particle   
        print P_lifetime(i,buffer)     # print the lifespan value of the particle   
        print " "

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 04/10/2012 at 09:25, xxxxxxxx wrote:

Now I only have two doubts.
The direction is not returning the particle direction but it is, in fact, returning a value that corresponds, somehow, to the direction of the emitter.
And I don't know how to interpret the wing value.
Could someone help me out on this?

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 05/10/2012 at 01:10, xxxxxxxx wrote:

Originally posted by xxxxxxxx

Now I only have two doubts.
The direction is not returning the particle direction but it is, in fact, returning a value that corresponds, somehow, to the direction of the emitter.
And I don't know how to interpret the wing value.
Could someone help me out on this?

All the information you're getting about a particle is listed and explained in the members of c4d.modules.particles.Particle (Python documentation).

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 05/10/2012 at 01:13, xxxxxxxx wrote:

Originally posted by xxxxxxxx

That solution only works if there are objects as childs of the emitter and the "Show Objects" option is on.
I want to be able to access the particle values even if there are no objects being created.
And the good news are... I DID IT!!!

Ah ok, I understand now why you couldn't use this solution. Glad you found how to read the particles data.

Helper

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On 05/10/2012 at 08:28, xxxxxxxx wrote:

However, the information in the SDK about the standard particles is almost non-existent.
Shouldn't it be more clear?

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 08/10/2012 at 02:36, xxxxxxxx wrote:

Originally posted by xxxxxxxx

However, the information in the SDK about the standard particles is almost non-existent.
Shouldn't it be more clear?

Have you looked into the Python docs (not COFFEE) at the page for the class c4d.modules.particles.Particle? I don't think there's more to add.

Helper

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On 08/10/2012 at 05:25, xxxxxxxx wrote:

Yes, I have looked into it, Yannick.
It tells me what information is present but it doesn't tell me where it is, how to get it, etc.

Helper

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On 08/10/2012 at 06:03, xxxxxxxx wrote:

Originally posted by xxxxxxxx

However, the information in the SDK about the standard particles is almost non-existent.
Shouldn't it be more clear?

Yes, it should.

Cheers,
André

Helper

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On 08/10/2012 at 07:53, xxxxxxxx wrote:

Also, besides not telling us how to get the raw data, it doesn't tells us how to get the elements out of the data.
As you can see from my exemplar above, it is not a straightforward method.

Rui Batista

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 08/10/2012 at 09:03, xxxxxxxx wrote:

Originally posted by xxxxxxxx

Also, besides not telling us how to get the raw data, it doesn't tells us how to get the elements out of the data.
As you can see from my exemplar above, it is not a straightforward method.

Rui Batista

The C++ documentation states that the array of particles is private (ParticleTag docs' page).
In fact the issue is: the C++ SDK's ParticleObject class isn't wrapped in Python. This class allows to easily access the particle array without having to figure how the particles are stored in memory.

Helper

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On 08/10/2012 at 09:37, xxxxxxxx wrote:

So, should it be in the python SDK in the current form?
Because, as it is now, it shows information that is not accessible directly.

Rui Batista

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 09/10/2012 at 01:42, xxxxxxxx wrote:

Originally posted by xxxxxxxx

So, should it be in the python SDK in the current form?
Because, as it is now, it shows information that is not accessible directly.

Particle class is used when overriding ObjectData.ModifyParticles(). I think it was wrapped for that purpose. But yes, it should be possible to access directly the particles in an emitter with the Python SDK.