Sun Hours Analysis Crasshing Grasshopper and Rhino


I keep running in to the same issue! no matter what I try the sun hours analyis wont run, it just starts and crashes the program. The exact same things happens with radiation analysis.

Ive tried a couple of other suggestions from other forum posts, but am having no luck. I would welcome any suggestions.

Check your units … Change your units to meters

done that, doesnt make any difference.

You should also see that you are running the simulation on parallel. Set Boolean to true on parallel to use multiple core processing .lastly also check the vectors of the surface face outside.

It seems, that after waiting for 20 mins, the model came to life at long last, but the geometry is so heavy that rhino can barely handle it. Am I doig something terriblly wrong?

how do I make them face outside?

Can you please share your GH script

its says new users cannot share files!

Thank you for your help on this by the way…

Try this file . (401.3 KB)

This worked perfectly… and then I put the grid size in, perhaps i dont need it then?

you have to specify sun positions to generate sun vectors. That was missing in your gh file.

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you’re amazing, thank you so much for your help Asisnath.

its not that the geometry is heavy; the level of detail in the analysis is quite high, if you shorten the analysis periods if possible with the data you need to create as well as what was previously mentioned running in parallel will make the analysis take even less time

Thanks man… I’m confused about that heavy geometry though as it’s very light when I bake it…

I still can’t seem to get the grid size thing figured out, but it seems to work without it so I’ll just ignore it.

You don’t want to ignore this parameter. Rather, try to understand.
My bet is that your model is too big and the grid size too small, so you have a huge grid to calculate.

Thanks… I’ve been trying to understand for two days haha! I’ll try a bigger grid size.

If the model buildings are say 3m x 5m average in this test geometry, what would a good grid side be in your opinion?

Ive tried it at 1, 2, 5, 10 and 20 and it crashes the model each time.

If this is the size of the model then the problem is elsewhere.
Upload the file so people can check.


I keep getting the ‘new users can not upload documents’ message. Would you be so kind as to pass me your email and I will send you the file via wetransfer?



You can paste the link to the file.

Here it is.