topic Re: Get number of elements in a mesh object in 3ds Max Programming Forum

Get number of elements in a mesh object

Anonymous — Thu, 28 Feb 2019 14:19:29 GMT

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

Re: Get number of elements in a mesh object

Swordslayer — Thu, 28 Feb 2019 15:46:57 GMT

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

Re: Get number of elements in a mesh object

Anonymous — Thu, 28 Feb 2019 16:19:11 GMT

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.

Re: Get number of elements in a mesh object

bigonethegod — Thu, 03 Sep 2020 17:52:21 GMT

Made this tiny modifier just for this!

https://gumroad.com/l/elements_count

Re: Get number of elements in a mesh object

bigonethegod — Thu, 03 Sep 2020 17:57:33 GMT

Made this tiny modifier just for this!

Mesh Elements Count

Re: Get number of elements in a mesh object

obaida_ds — Mon, 01 Aug 2022 00:02:07 GMT

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

Re: Get number of elements in a mesh object

denisT.MaxDoctor — Sun, 31 Jul 2022 22:26:24 GMT

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

Re: Get number of elements in a mesh object

obaida_ds — Sun, 31 Jul 2022 23:06:55 GMT

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

Re: Get number of elements in a mesh object

denisT.MaxDoctor — Sun, 31 Jul 2022 23:17:45 GMT

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

Re: Get number of elements in a mesh object

obaida_ds — Sun, 31 Jul 2022 23:22:24 GMT

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

Re: Get number of elements in a mesh object

obaida_ds — Mon, 01 Aug 2022 00:02:32 GMT

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 🙂

Re: Get number of elements in a mesh object

denisT.MaxDoctor — Mon, 01 Aug 2022 00:06:19 GMT

@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) )

Re: Get number of elements in a mesh object

obaida_ds — Mon, 01 Aug 2022 09:42:44 GMT

ok , not that much 🙂 ,

if you can help here we all will appreciate that 🙂

Re: Get number of elements in a mesh object

denisT.MaxDoctor — Mon, 01 Aug 2022 00:14:45 GMT

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

Re: Get number of elements in a mesh object

obaida_ds — Mon, 01 Aug 2022 01:17:19 GMT

thank .

Re: Get number of elements in a mesh object

denisT.MaxDoctor — Mon, 01 Aug 2022 01:37:55 GMT

@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.

Re: Get number of elements in a mesh object

Serejah — Mon, 01 Aug 2022 06:40:07 GMT

@denisT.MaxDoctor написал (-а):
@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

Re: Get number of elements in a mesh object

obaida_ds — Mon, 01 Aug 2022 09:44:43 GMT

I think I found it , Thanks for contribution :

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

Re: Get number of elements in a mesh object

denisT.MaxDoctor — Tue, 02 Aug 2022 00:23:24 GMT

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!