Get number of elements in a mesh object

[Anonymous]

Is there a way to look at a mesh object and find out how many elements are contained within? I know I can access elements by using face bit arrays but was hoping there would be an easier way that does not involve having to do it this protracted way. I was hoping there may be a <mesh>.getNumElements that I can access, but I have not found such an attribute. I probably missed it.

Thanks

[Swordslayer · Accepted solution]

'Fraid not but you can make your own. See for example the tryGetMeshElements function used here for inspiration.

[Anonymous]

Ah buggar. Oh well, thanks for the link, I am sure it will prove very useful.

Seems like it would be a worthwhile addition to the MeshOps or PolyOps interface though.

[bigonethegod]

Made this tiny modifier just for this!

https://gumroad.com/l/elements_count 

[bigonethegod]

Made this tiny modifier just for this!

Mesh Elements Count 

[obaida_ds]

sorry , the function was not working so I deleted it .

[denisT.MaxDoctor]

Please test your solutions before posting them...

try:

delete objects
gc()

s = geosphere name:#test_mesh segs:4 wirecolor:orange isselected:on
converttomesh s
meshop.explodefaces s #all 0

GetMeshElements s

[obaida_ds]

Thanks for Feedback , ofc it should not be the best way but it works !! (not yet , need more tests)

[denisT.MaxDoctor]

better now. at least it somehow works 🙂 ... but it gives wrong number 

[obaida_ds]

🙂 , actually I tested it on copied faces (not detached) so it works , detached faces keep its index !! .

[obaida_ds]

fn GetMeshElements obj = (
	local tf = obj.faces as bitarray, 
	el = meshOp.getElementsUsingFace obj 1, n = 1
	if el.numberset != obj.numfaces do (
		local lf = tf - el
		while lf.numberset != 0 do (
		       lf -= meshOp.getElementsUsingFace obj (lf as array)[1]
			n += 1
		)
	)
	n
)

I Hope this one will work 🙂 

[denisT.MaxDoctor]

---

@obaida_ds wrote:

I Hope this one will work 🙂 

---

Great! Now let's test the performance... 😉
change the number of geosphere segment to 20 first.... 

delete objects
gc()

s = geosphere name:#test_mesh segs:20 wirecolor:orange isselected:on
(
	converttomesh s
	meshop.explodefaces s #all 0
)

(
	t0 = timestamp()
	h0 = heapfree
	n = GetMeshElements s

	format "num:% time:% heap:%\n" n (timestamp() - t0) (h0 - heapfree)
)

[obaida_ds]

ok , not that much 🙂  ,

if you can help here we all will appreciate that 🙂

[denisT.MaxDoctor]

for reference:
* the method shown by Swordslayer above takes ~30 ms
* another method (that you can find on CGTalk) takes ~10 ms

[obaida_ds]

thank .

[denisT.MaxDoctor]

---

@obaida_ds wrote:

thank .

---

Anyway you are on the right track. The best practical solution is to first try to do it yourself, then find the highest rated and find out how yours differs from the best.
There was a big discussion on CGTalk about optimizing the search for mesh elements ... as a result of testing and discussion, the decision took the final form. Unfortunately, CGTalk is now broken by "fatal improvements". And even I can not find this topic, although I was a direct participant in it. Maybe someone will be lucky to find it somehow.

[Serejah]

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@denisT.MaxDoctor  написал (-а):

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@obaida_ds wrote:

thank .

---

And even I can not find this topic, although I was a direct participant in it. Maybe someone will be lucky to find it somehow.

---

All I remember is this topic about poly elements count.

A faster method for retrieving element count 

[obaida_ds]

I think I found it , Thanks for contribution :

https://forums.cgsociety.org/t/how-to-quickly-eliminate-elements-with-lowest-face-count/1692456/26

[denisT.MaxDoctor]

A faster method for retrieving element count 

How to quickly eliminate elements with lowest face count? 

yes... those are the discussions I was talking about. Thanks guys for finding it!