'floor' simulation project by djamu


#1

I created a new simulation project called 'floor':

floor


More of my public projects can be found here.


#2

Hi @djamu,

With your CAD model you have uploaded, some of the volumes contain many faces which is likely the reason for meshing errors. Which CAD tool are you using?


#3

Thanks for your reply,

I thought the same, this is an STL meshed design that I converted
  to volumes using Solidworks, I already had removed the threads on
  the bolt you're showing.
I'm a TD used to using meshed 3D programs ( Lightwave, Maya
  etc.), I'm very new to using Solidworks and the likes.


My main problem is that I don't seem to be able to convert curved
  faceted surfaces to curved solids, I'll try remove those bolt
  heads and see how far I get.
It's a pity though that I can't use meshes directly. A workaround
  would be that I could directly upload meshed objects and skip
  geometries altogether...

#4

@djamu, mesh upload is in fact very possible:

When you click on ‘upload mesh’, you will find the available formats and can then upload your desired mesh.


#5

Thanks for your prompt reply,
I found this already but none of my programs can convert to either UNV / OpenFaom / EGC / MED /CGNS
Are these formats using meshes in the same sense as STL does ? And why would an STL / PLY not be possible ?
( uploading as Mesh I mean )
I know I can upload STL as geometrie, but FEA analysis isn’t possible like that.


#6

@djamu, STL files describe only the surface geometry of a three-dimensional object, thus volume meshing as you would want to do in this case is not possible since the file type does not contain the necessary information.


#7

.stp or .step is the most recommended file type but conversion of it from an .STL doesn’t seem to present a good option either


#8

Ok, makes sense, any hint as to what I could use to convert an STL ( or whatever ) into either UNV / OpenFaom / EGC / MED /CGNS formats ?


#9

No this isn’t possible either :weary: as far as I know - STLs are not easily modified (which is frustrating). Is this a model that you’ve created? Or is there a similar model that’s in a .step format that you could use instead?


#10

It’s my model, original is a Lightwave model that I’ve exported to STL, I can export it to whatever ( mesh ) type model but it seems I always have to convert it to a volume type object… ( Ascii type STL are quite easily modified btw. :wink:
I guess I’ll just have to redraw it in Solidworks then … It’s not a complicated model, but I’d hoped to circumvent that.

thanks for your time…


#11

Is it not possible to export as STEP directly from Lightwave?


#12

No it’s an animation program, not a CAD one, those programs ( as with MAX / Maya / etc … ) have no concept nor need for volumes, whenever a volume is needed for simulation ( special effects for example > fire / smoke / fog ), it’s 3D appearance gets either faked by using layers of 2d planes or approximated by using voxel based volumetrics.

So although both classes of programs ( animation / CAD ) use both 3D objects, their definition of those is very different.
This all is a longstanding issue in the animation world -the inability to export to CAD and vice versa-

STL is an exception to that, in the sense that it’s about the only animation type 3D format used by ( hobbyist) CAD programs. > only popularized by the upcoming of (hobbyist) 3D printers.

The same problem presents itself when using 3D scanners, they use point clouds that can be easily converted to meshes ( as I define them ), but are almost impossible to convert to CAD based file formats…

From my perspective, CAD files are a really weird way to describe 3D objects.
For example why differentiate between extrudes and champfers etc… when it can be all facets :wink: .

I think your service will gain immense popularity if it would be able to accept not only STL, but even better to use FBX and / or ( even better ) DAE
FBX https://en.wikipedia.org/wiki/FBX
DAE https://en.wikipedia.org/wiki/COLLADA

both are well known interchange formats.
DAE is XML based

Jan


#13

Jan,

Thanks for the explanation here - I’m quite unfamiliar with animation programs myself. I think this does come down to the difference in definitions that you refer to: [quote=“djamu, post:12, topic:26671”]
So although both classes of programs ( animation / CAD ) use both 3D objects, their definition of those is very different.
[/quote]

It seems that the animation 3D objects and point cloud data is intended to represent the external surface of an object which is not meshable from a finite element engineering simulation definition.

Even with STL’s - these can only be used for external aerodynamics simulations since again there is no volume information present with this file type.


#14

That ( STL ) seems to be the reason why your engineers are unable to use it for anything else then aerodynamics.
On the other hand, it seems the voxels ( and their variable 3d spaced grid size ) I was referring to is very similar to “meshing” a CAD model.

I’ll look into that, as that would enable you to process data-sets used in animation and then render them back as animation. ( for example to render waves more realistically ).

I’m a pretty good programmer myself ( I’m a TD after all ). And might put some effort into doing that if you’d give me some info / access on the API you’re using.
Good commercial voxel based animation/simulation programs are quite expensive and troublesome to use as they tend to use a lot of virtualized parameters.
A cloud based alternative ( with a modified API ) as yours might be a good alternative for those, especially if one could use real life parameters…
No doubt it would elevate the potential of your service, and I know for a fact that quite a lot of studios would use it…

Jan


#15

@djamu I see you’ve run the analysis now, nice - hope the setup went relatively smoothly once the solid model was uploaded.

Back to our conversation from yesterday - from the product side, we will likely be enabling stl meshes (volume meshes) at some point in future.

Not sure what TD stands for (you might have to expound on that)…you’re the first person to bring forth this animation concept - it’s not a typical use case for mechanical engineers, designers, etc.


#16

TD means Technical Director, which is usually a senior lighter / rigger / animator / … other niche specialty.
Who does the technical planning of productions
I specialized myself in mechanical rigging and renderfarms ( think compute clouds )…
which is quite similar to the hardware topology you’re using.
Looking at some demos yesterday, I saw already some people trying what I mentioned yesterday. ( An oil rig flooded by a superwave ) so it’s unlikely that I’m the first thinking of it…
In any case I do know quite a bit of the things I mentioned. I live in Belgium and ( used to ) speak fluent German
:wink:


#17

Hi @djamu, you mentioned a question about adding nodes during our phone call just now. @AnnaFless can you help here? Thanks!