Any way of Carrara working out the surface area of an object?

Headwax

Hi Brain Bank :)

 say I have a flat irregular plane (think a surfboard fin plan or a random shape).

Was wondering if there was any way in Carrara to get an automatic area measurement of it - rather then counting sq cm's by eyeball?

 

thanks in advance ;)

WendyLuvsCatz

a 3D printer slicer program should do this

Meshmixer could do it if you still have that

Headwax

thanks Wendy, will check in those, was hoping carrara had a hidden talent ;)

Bunyip02

Do you have a CAD program ?

Did a screenshot of your pic, saved as jpg.

Opened CAD, went to Insert an image

Once image was in drew a reference line and obtained the length

Worked out the scale ratio assumming a 15cm length

Applied scale to inserted image

Drew a Polyline around the fin

Clicked on Polyline to get the Area, which was 74.084 cm2

EDIT - LibreCAD is free, was able to get a Polyline area out of it but was not as User-friendly as CorelCAD which I obtained through a Humble Bundle package.

Bunyip02

LibreCad - just tried exporting a cube primitive from Carrara as a dxf file.

LibreCAD can import a Block which is a dxf file. File - Import - Block

Then Tools - Info - Polygonal Area - trace around the area you want, and read off the Area value in the Command Line

If you need more details about this method just yell !!!

Bunyip02

Polygon Trial

Quick Carrara model

LibreCAD

NOTE - I have not checked any issues with unit differences in the conversion, will do if you are interested ....

Headwax

Thanks Bunyip 02 :) Very kind of you to go to all that trouble and making such a clear walk through! . Ah the areas just need to be relative rather than absolute. The idea is to compare fin areas, so to take a planshape and tweak it but still keep the same overall area.

I have a few free cad programs plus amateur autocad, I'll check those out ! Thanks for the idea and I'll keep an eye out for humble bundle corel cad.

I see they are doing Christmassy things at the moment.

Bloody hot today!

Stezza

ahh... you need to find the area under a curve and above the x-axis modeled by function f(x) in the domain interval x within [a,b]. This method requires knowledge of integral calculus.

this little duck has NFI 

Headwax

Stezza said:

ahh... you need to find the area under a curve and above the x-axis modeled by function f(x) in the domain interval x within [a,b]. This method requires knowledge of integral calculus.

this little duck has NFI 

 

ha ha you sound like the research gate papers I have been reading on aerodynamics for the last two months - people get grants for anything - like some guys figured out if you put more support under the part where you stand on a hollow surfbaord then it flexes less :)

 

Headwax

random pic showing vortex generators (left fin) and passive leading edge slots  (both fins)  - carefully sanded ha ha 

the little holes at the rear of left  fin are supposed to be for inducing a passive venturi to reattache the laminar boundary layer at high angles of attack - well that wa s my idea anyway ;)

let you know if it works  (probably work better if I sanded themproperly)

 

the grooves are supposed to interrupt the spanwise flow and reduce the induced vortex drag coming off the tip where the high and low pressure ares try to mingle - kind of like winglets on air-o-planes

 

WendyLuvsCatz

be careful mate 

lots of sharks munching on people lately

Headwax

WendyLuvsCatz said:

be careful mate 

lots of sharks munching on people lately

I have the new invisability cloak the Chinese just invented :) Thanks for the warning. Had a surf tother day surrounded by about  thirty dolphins and their babies . That was interesting. The buggers never look where they are going. Too busy showing off

Headwax

Hi Wendy did you mean Meshlab? found this How to Measure Surface Area of a Mesh | Foundry Community   - you need to divide by two to get the correct answer in sq cm ?

Couldn't see in in my Cura slicer though

Bunyip02

Headwax said:

Thanks Bunyip 02 :) Very kind of you to go to all that trouble and making such a clear walk through! . Ah the areas just need to be relative rather than absolute. The idea is to compare fin areas, so to take a planshape and tweak it but still keep the same overall area.

I have a few free cad programs plus amateur autocad, I'll check those out ! Thanks for the idea and I'll keep an eye out for humble bundle corel cad.

I see they are doing Christmassy things at the moment.

Bloody hot today!

Check that you can import a dxf file in your CAD programs, most will have the Polyline/area hidden away some-where. I used AutoCAD all the time when I was working as a Design Drafter many years ago.

Meshlab sounds interesting as well.

Definately hot, been on my laptop as my graphics computer does not like the heat apart from a few hours early in the morning or late at night, and I am not a morning person normally !!!

WendyLuvsCatz

possibly both do it

Meshlab does do a lot of things but it was Meshmixer, I recall it having this function and Google confirms it

https://meshmixer.com/

Bunyip02

Did a comparision of Meshlab and MeshMixer both of which I have installed on my Graphics Computer

Meshlab

Edit - Select Faces in a Rectangular Region

Filters - Quality Measure and Computations - Compute Area/Perimeter of Selection

MeshMixer - could not find anything obvious for Surface Area, mind you I am only using the program for the first time

 

 

Diomede

Here is a suggestion for volume of oddly shaped objects that has only a small chance of success - but not crazy talk.  Start with a 1unit x1unit x 1unit cube and stack them vertically to build a tall water tank.  Use a shader to demark the vertical side of the cube in 10 steps or 100, or whatever level of accuracy you need.  Fill with a Fluidos amount of water bigger than your object.  Take your object and lower it into the fluidos tank.  Note how high the water level goes on the calibrated tank.  Subtract the initial level.  Calculate volume of odd shaped object from difference.

- So much can be wrong about this suggestion!  The internal math of Fluidos might not work this way at all.  Or, the way in which Fluidos simulates the flow of water might not take into account volume of water.  Even if the internal math of Fluidos could work this way in an appropriate program, Carrara physics might not.  I haven't tried this, and I have not used Fluidos enough to have a guess if this would work.

EDIT:  The metric based world should be able to choose a unit that converts easily to a volume.  Meters to liters, or whatever.

WendyLuvsCatz

under Stability 

Bunyip02

Thanks Wendy !!! Not an obvious place to hide it !

Bunyip02

Diomede said:

Here is a suggestion for volume of oddly shaped objects that has only a small chance of success - but not crazy talk.  Start with a 1unit x1unit x 1unit cube and stack them vertically to build a tall water tank.  Use a shader to demark the vertical side of the cube in 10 steps or 100, or whatever level of accuracy you need.  Fill with a Fluidos amount of water bigger than your object.  Take your object and lower it into the fluidos tank.  Note how high the water level goes on the calibrated tank.  Subtract the initial level.  Calculate volume of odd shaped object from difference.

- So much can be wrong about this suggestion!  The internal math of Fluidos might not work this way at all.  Or, the way in which Fluidos simulates the flow of water might not take into account volume of water.  Even if the internal math of Fluidos could work this way in an appropriate program, Carrara physics might not.  I haven't tried this, and I have not used Fluidos enough to have a guess if this would work.

EDIT:  The metric based world should be able to choose a unit that converts easily to a volume.  Meters to liters, or whatever.

Looks like Headwax is spoilt for choices now !!!  - 1 Cubic metre = 1000 Litre

Stezza

A typical Australian would use the 'ROE' method. 

cdordoni

Deskartes 3D Data expert (free) also has some tools for volume and surface area.

Headwax

WendyLuvsCatz said:

possibly both do it

Meshlab does do a lot of things but it was Meshmixer, I recall it having this function and Google confirms it

https://meshmixer.com/

thank you Wendy

Headwax

Stezza said:

A typical Australian would use the 'ROE' method. 

 

ha ha I had to google it. I hated maths at uni. The last purely maths thing I did I got 49 out of 50 first semester and 1.5 out of 50 the second semester. So I luckily passed...

Headwax

cdordoni said:

Deskartes 3D Data expert (free) also has some tools for volume and surface area.

 

thanks that looks very interesting will check it out ! Deskartes 3D Data expert

Headwax

Bunyip02 said:

Headwax said:

Thanks Bunyip 02 :) Very kind of you to go to all that trouble and making such a clear walk through! . Ah the areas just need to be relative rather than absolute. The idea is to compare fin areas, so to take a planshape and tweak it but still keep the same overall area.

I have a few free cad programs plus amateur autocad, I'll check those out ! Thanks for the idea and I'll keep an eye out for humble bundle corel cad.

I see they are doing Christmassy things at the moment.

Bloody hot today!

Check that you can import a dxf file in your CAD programs, most will have the Polyline/area hidden away some-where. I used AutoCAD all the time when I was working as a Design Drafter many years ago.

Meshlab sounds interesting as well.

Definately hot, been on my laptop as my graphics computer does not like the heat apart from a few hours early in the morning or late at night, and I am not a morning person normally !!!

 

thanks will check that DXF , yes I like to sleep in till 7.00 am but that sun blasts in at 5.30 :( :)

Headwax

Bunyip02 said:

Diomede said:

Here is a suggestion for volume of oddly shaped objects that has only a small chance of success - but not crazy talk.  Start with a 1unit x1unit x 1unit cube and stack them vertically to build a tall water tank.  Use a shader to demark the vertical side of the cube in 10 steps or 100, or whatever level of accuracy you need.  Fill with a Fluidos amount of water bigger than your object.  Take your object and lower it into the fluidos tank.  Note how high the water level goes on the calibrated tank.  Subtract the initial level.  Calculate volume of odd shaped object from difference.

- So much can be wrong about this suggestion!  The internal math of Fluidos might not work this way at all.  Or, the way in which Fluidos simulates the flow of water might not take into account volume of water.  Even if the internal math of Fluidos could work this way in an appropriate program, Carrara physics might not.  I haven't tried this, and I have not used Fluidos enough to have a guess if this would work.

EDIT:  The metric based world should be able to choose a unit that converts easily to a volume.  Meters to liters, or whatever.

Looks like Headwax is spoilt for choices now !!!  - 1 Cubic metre = 1000 Litre

 

thanks for those walkthrough and yes, spoilt for choice! Better than the opposite :)

Headwax

Diomede said:

Here is a suggestion for volume of oddly shaped objects that has only a small chance of success - but not crazy talk.  Start with a 1unit x1unit x 1unit cube and stack them vertically to build a tall water tank.  Use a shader to demark the vertical side of the cube in 10 steps or 100, or whatever level of accuracy you need.  Fill with a Fluidos amount of water bigger than your object.  Take your object and lower it into the fluidos tank.  Note how high the water level goes on the calibrated tank.  Subtract the initial level.  Calculate volume of odd shaped object from difference.

- So much can be wrong about this suggestion!  The internal math of Fluidos might not work this way at all.  Or, the way in which Fluidos simulates the flow of water might not take into account volume of water.  Even if the internal math of Fluidos could work this way in an appropriate program, Carrara physics might not.  I haven't tried this, and I have not used Fluidos enough to have a guess if this would work.

EDIT:  The metric based world should be able to choose a unit that converts easily to a volume.  Meters to liters, or whatever.

 

wow, that's a bit of lateral thinking! When i get my head around Fluiodos again I will try it :)

Headwax

just ran an obj through meshlab and meshmixer and got the same area - so that's a relief :)

Stezza

Stezza said:

A typical Australian would use the 'ROE' method. 

= Rack Of Eye