# How can i find, my grid size is selected good value

hello dear @mostapha

1. how can i find, my grid size is selected good value? i gonna calculate radiation.
and

2. how to find, how many grids are there on a shape?

3. how can i determine the number of grids? (can i determine a special value for grasshopper/ladybug?)

12345_autosave61.gh (395.3 KB)

For Q1, there is no good value for all scenario.For masterplan phase, you can set a big grid-size to generate corse result quickly. If you want to get smooth result, you should set a small grid-size. And small grid-size will take more time to finish the calculation.
Here is a demo

For Q2, the F number of mesh is just the number of grid.

In this pitcutre, there are 2280 grid on the shape.

For Q3, In my experience, for masterplan phase, you can set grid-size as 5 meter. For detailed analysis, you can set grid-size as 0.5 meter or smaller.

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hello
dear @minggangyin
Thanks a lot.

hello dear @minggangyin
How can i find maximum value of radiation?

best

@ahad it is very easy to get it .
Here is the demo image and grasshooper file

12345_autosave61-fix.gh (422.8 KB)

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dear @minggangyin
thanks a million.

hello
dear @minggangyin

like as you know: (No. grid * average grid size = area of shape)
but with respect to below picture:
No. grid=7379
average grid size = 0.06 m2
total area=7379*0.06=442.74 m2
but my total area is just 18.2 m2. (i calculated area by rhino and i created my shape in rhino too.)

best

Get the mesh area with GH native components. Will be much accurate that what you wrote above.
-A.

Connect the same Area component to the output radiationMesh. You should get the same area as the input brep.
-A.

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You right @AbrahamYezioro
In this way
Isn’t there any relation between between gridSize and area?
or number mesh and area?

best

@AbrahamYezioro

number mesh (7379)
multiplied by average gridsize (x)
=18.3
then
gridsize= 18.3/7379=0.0025

but as shown in below picture the grid size value = 0.06.

@AbrahamYezioro
in the above picture, what is the unit of gridsize?? meter or meter square??
if it is meter square,
0.0025…0.05 multiplied by 0.05
in this way 0.05 and 0.06 are so close.

I really don’t understand what is the issue here.
The grid size input is a wishful thinking setting. Since LB/HB is using GH meshing algorithms it doeasn’t guarantee that each grid size will fit the setting.
This setting should be given according to the model units. So if you work in mts give it in mts, and so on.
-A.