How do you make plug-ins for sketchup

BTM

I've been taking a look at the sketchup API, and am currently a bit intimidated.
I never realized how many different methods, classes and modules there would be! Up until now, everything I've done has been very simple, but I don't even understand half of what these things mean, and it would take me forever to find anything specific!
...also, how do you add global variables throughout the script? Is it still setVar("foo",1), getVar("foo"), and getSetVar("foo",0), like in sketchyphysics?

Chris Fullmer

SketchUp has (at least)

variable - local variable
@variable - Instance variable
@@variable - Class Variable
$variable - Global Variable

local variables are available only within the method in which they are defined.
Instance Variables are available through the entire class instance.
Class Variables are available for all instances of a class.
Global variables are available for all classes. They can be accessed from any ruby script. If you make one called $my_special_global_variable and someone else makes one with the same name, there will be a conflict.

I know that doesn't explain instance and class vairables very well. Sorry, I'll have a go at it.

In SketchUp, when you make a tool, you make it as a class. So every time the tool gets activated, it creates a new instance of the class. Instance variables are only available within that instance of the class. When the tool is activated again, those old instance variables are not available to the new instance. But Class variables would be available from one activation of the tool (instance of the class) to the next. So lets say that you have a tool that draws a circle and the user can input the size and segments of the circle. If you used an instance variable to hold the user input size and segment count, then the tool keep their values only while it was active. Once they de-activate the tool, then re-activate it, it creates a new instance of the tool, and the instnace variables are lost, so it would return back to whatever defaults the script provides. But if you use Class variables, then those variables stay active from one activation of the tool to the next. They only get reset once SketchUp is closed down and restarted.

Thats it to the best of my understanding. I only really understand this within a SketchUp context. So I'm sure there;s more to it than just that. But that is a start on local, instance, class, and global variables.

There are also constants, symbols, and maybe more? THey are types of variables I think.

Chris

l.frisken

I've started trying to learn how to use ruby but I'm having a lot of trouble getting input points to work. U'm what would be the simplest way for me to make a simple tool that tells me the coordinates in 3 dimensions of whatever I'm clicking on?

Chris Fullmer

That seems to be a popular thing to want to do, but in my mind, its a pretty involved task. In order to get the onlinck function to work, it has to be implemented from within a tool. Have you already got a tool class working correctly?

Chris

l.frisken

within a tool? (hmm I need to study more! ) well I was wanting to make a line drawing ruby that involved two clicks like the example file. But from just trying to examine the file I realized that it was quiet a complicated process, much more than just drawing a line using ruby! I wish that google could have made this function a little simpler, seeing as like 80% of the plugins I have used use something like this. I guess I need to start on some other more simple things. I have read a book on O O programing before but things are a little rusty now! (classes, methods... arrgghh! )

BTM

Ahh, thanks for the advice on variables Chris! %(#808080)[(and thanks for all the other helpful advice and tips you've posted in this descussion )]

BTM

I've learned some of the sketchup ruby API, and understand why most codes work how they do, but my problem is making a code that works. I know how something works when I see it, but can't write one myself. It's like being able to hear or read, but not speak or write

Chris Fullmer

I think some of the "easiest" scripts to start writing are ones that begin by iterating through the model and doing something to the geometry. Here's a few variations of some basic examples. Then tweak them and expand on them to make them more and more involved.

pushpull all faces in the model
pushpull selected faces only
select all faces that have a certain surface area.
select all faces that have a surface area within a specified tolerance.
Delete all lines that are not drawn on an axis.
Delete all faces in the model or all faces from a selection, leaving just edges

Anyhow, thats a small start. Those should all be fairly straightforward.

Chris

free agent

wow im finally interested in learning ruby it would be awesome to not have to request rubies, just make em urself... and share of course.

remus

youve got me tempted now, chris. I'll post my efforts this evening

Click Draw

Is Ruby on Rails the same as Ruby?

Thanks,
Jeff

Chris Fullmer

Rails is like an extension of regular ruby. So Ruby is the main language, and rails is a "ruby gem". Its still the same language, but it adds more features and functionality especially developed for web developers (I think).

Chris

Jim

How about a "heal" script that joins broken, but co-linear edges?

Chris Fullmer

I think all those suggestions can be written in 10 lines of code or less. So they are good compact examples too.

Some of the more efficient programmers might be able to pull them off in one or two lines, but for me 10 or less would be good. It might take more than that too of course.

Chris

EDIT: 10 lines doesn't include any menu system implemenetation. Since I write everything in Jim's WebConsole, there's no need to make a menu for it until I'm ready to save it as a ruby file.

Click Draw

So literature to buy if one was to, Ruby or ruby on rails? Sounds like ruby on rails would be the next step or more advanced than ruby?
Thanks,

Jeff

Jim

Rails is not Ruby. Rails is a web application framework written in Ruby. Forget about Rails if you're interested in Ruby for SketchUp.

You can't go wrong with the Pickaxe book. However, I don't believe you need to purchase anything as there is plenty of material online to get quite in-depth.

@click draw said:

So literature to buy if one was to, Ruby or ruby on rails? Sounds like ruby on rails would be the next step or more advanced than ruby?
Thanks,

Jeff

Click Draw

Gotcha, thank you. Good advise.

Cheers,

Jeff

BTM

@chris fullmer said:

pushpull all faces in the model

AAHHHHH!!!! It took me HOURS to find the typename function!!!!!!!!!!!!!!!!!!!
...but at least I know now

model = Sketchup.active_model
entities = model.active_entities
#  -  -  -  -  -  -  -  -  -  -  -  -
entities.each { |entity| 
   if entity.typename == "Face"
   entity.pushpull 10
   end
}

(WHY can't it be easier to find things on the sketchup ruby API list????)
Also, it gives weird, unexpected results sometimes: it seems to pushpull the new faces it makes too

AdamB

[Slightly OT]

I've always been very careful to use Object#kind_of? rather than Object#class so that code works with any derived classes too. (Rather than just testing for an explicit class).

Good idea? Bad idea?

Adam

Chris Fullmer

Awesome!

My theory on why it pushpulls some new faces is because it is going through .each entitiy in the entities list. Well, its a dynamic list of the entities in the model, so as soon as you pushpull a face, it creates new faces and adds them somewhere to that entities list. It might be to a part of the list the it has already processed, so it won't do those faces. Or they might get added towards the end of the list to a part that has not yet been processed, so it will pushpull those when it reaches them.

The way to counter that is instead of pushpulling all faces as you find them, add them to an array. Then once you've gone through all the entities and found all the faces, then run through the faces array and pushpull them.

Another check you might want to add is a vildity check to make sure the face you are about to pushpull is valid. Say you have more intricate geometry with original faces facing eachother. Then if one gets pushpulled first to the exact distance that it overlafs the other face, you might very vell end up deleting the other face, and it will give an error when you try to pushpull it. So if you do something like

faces.each do |face| face.pushpull( 100 ) if face.valid? end

Then it will skip faces that have been deleted in the proces of pushpulling other faces.

And the API gets much easier to work with after a while. I promise. Just for fun, read through the methods in a cuple of classes everyday. And re-read them often. Its helpful.

Well done,

Chris