How to make two objects have 'same volume' but different parameters, surface area etc

rhino

(Intexlann) #1

hi guys,
i know this is just basic but since rhino is a very powerful software i think there’s some tools and commands to do it… which i couldn’t find…i want to create some different looking shapes like cube, cuboid, 3d hexagon, sphere etc to have same volume. Through calculations it can be done for simple forms but for complex forms some commands needed, i m trying to make some examples for my presentation please do help

example file.3dm (60.2 KB)


(David Cockey) #2

Volume scales as the length cubed. To scale object A to be the same volume as object B, first use Volume to measure the volumes of A and B. Then Scale A with the ratio of cube root of (volume of B divided by volume of A).


(Intexlann) #3

how do i do the cube root division in rhino?


(David Cockey) #4

One method:

exp((ln(B/A)/3) B is the volume of object B and A is the volume of object A


#5

Here is a quickie script hack…

Edit - new version - fixed a number of errors and cleaned it up…

ScaleToMatchVolume.py (1.9 KB)

–Mitch


(Intexlann) #6

thanks alot


(Intexlann) #7

do u know how to check surface area too??


(Michael Pryor) #8

Do you use grasshopper? If so Pufferfish has has Scale To Area, Scale To Volume, and Scale To Length components that will let you scale any geometries (that are measurable) to those specified sizes, uniformly or non uniformly.


(Intexlann) #9

okay good one i like pufferfish but how do i find out the surface area of selected complex object/form?


(Michael Pryor) #10

In grasshopper the area component will give you surface area. For the Pufferfish Scale To Area component you just plug in the geometry and then in the area just input the desired surface area and it will resize it to be that surface area.


#11

Here is another script adapted from the first one that checks area…

ScaleToMatchArea.py (1.5 KB)


(Intexlann) #12

yes thats so cool thank you so much… God bless!


(Intexlann) #13

thank you so much…God bless!


(Michael Pryor) #14

And if you want to deform it non-uniformly but still maintain a desired area you can change the weight of the X,Y,Z factors