Grasshopper Calculation

Hello everyone, my first time on here and i already got a question - I hope you can help me =)

So I got a problem in Grasshopper -> the task I want to fulfill is:

I have 2 curves that I subtract from each other (base curve and subtractive curve)

The goal is to get something like subtractive colormixing

-> so the the base curve is something like a white paper

-> if i add a color to it the paper gets darker

it works - but the problem is - if I put the slider of the subtractive color/curve to for example 100 and the base curve is at 50 it get minus values --> whereas the minum in total should be "100 - the numbers of the subtractive curve"

I know it may be a bit confusing - but it really should be just a little trick - so to make it a bit more clear i add screenshots:

As you can see - on top I have a list with 50 as the base curve - from that I subtract the list on the left -> so I get minus number in the list on the right -> and you can see on the rhino window on the right - that the curve is below zero - whereas it should exactly match the upper curve in that situation

to give you a understanding what i want it to look like in reality in that case - I give you another screenshot:

So that is what it should look like - so for example -> If it is 50-94.68 -> value on the right list should hit a minumum at 5.32 (100-94.68)

--> so 100-value in left list should be minumum in right list

I hope i could make it a bit understandable at least - and I really hope that you could help me

Thank you so much in advance

and I hope to hear from you soon

Tom =)

PS: Screenshots are attached beneath as they wont show in the discussion

AND HERE IS THE GRASSHOPPER FILE: Farbenmischer.ghx

Attachments:

Screenshot 2014-02-14 00.54.11.png, 441 KB
Screenshot 2014-02-14 01.01.13.png, 429 KB

Replies to This Discussion

Permalink Reply by Jonah Hawk on February 13, 2014 at 6:32pm

http://www.grasshopper3d.com/forum/topics/how-to-get-help-when-you-...

Permalink Reply by David Rutten on February 14, 2014 at 1:40am

Hi Tom,

it's a bit hard to see exactly what's going on in the screenshots. Can you post the GH file?

David Rutten

david@mcneel.com

Permalink Reply by Thomas Lechner on February 14, 2014 at 2:10am

Added it to the discussion above - thank you very much =)

Permalink Reply by Thomas Lechner on February 14, 2014 at 6:04am

After a lot more trial and error and some search here on the website I could get a step further and am already at the finished result - I just can't get the last step to work. Maybe someone knows a quick fix =)

Ok so my Problem is:

I get values in list A -> if the value is higher that the corresponding value in list B than this value of A can be written to List C

-> but if the value in List A is lower than value in List B than the value of list B should be written in list C

-> I could get it to work to the point you see here - that if value in list A is lover than value in list B a 0 is written to list C -> so does anone know how i can get it to work that the corresponding value of list B is written to list C (where now are 0)

So that list C looks like:

0 16.76732

1 16.84103

...

18 24.54

19 28.27

...

Thank you very much =)

Permalink Reply by Danny Boyes on February 14, 2014 at 6:28am