Counting Component Instances Returns Incorrect Number?

Developers Ruby API
,
1

Suppose I have a Component called “Rock”. I want to know how many instances of “Rock” exist in the model. The only two available API methods are count_instances and count_used_instances.

They will return the correct counts if a Rock is on it’s own in the model, or if the Rock is inside a group.
Rock
Group > Rock

But if there is further nesting, the count is wrong. For instance, a Rock inside another Component inside a Group will not be counted.

Group > ArbitraryComponent > Rock

Example code:

wanted_component = 'Rock'
Sketchup.active_model.definitions[wanted_component].count_used_instances

Will I need to write my own recursive loop to find every instance of a Component? Or is there another method?

2

It seems to work OK for me. Can you post a model showing the problem?

3

Works as expected for me too. Could you have accidentally made your test component unique?

4

No, count_used_instances is the one you want.

The count_used_instances method is used to count the total number of component instances in a model using this component definition. This method takes into account the full hierarchy of the model.

Please post sample model and sample code if you are getting unexpected results.

5

This also works.

component.definition.instances.count

or

Sketchup.active_model.definitions[wanted_component].instances.count

6

This would only count an instance once even if its parent components has multiple instances.

7

Are you sure you used #count_used_instances (the newer, smart method that checks the full hierarchy) as is written in your example code and not #count_instances? (the old method that just checks the number of instance objects)?

8

Could you demonstrate this? According to my tests:

mycomponent.definition == Sketchup.active_model.definitions[mycomponent] = true

and mydefinition.instances returns an array of all the used instances.

9

Try placing any of those component instances within another component and then make a few copies of that parent component. The number of instances of the parent component doesn’t affect the number of “actual” instances of the child component (child_component.instances.size or child_component.count_instances). However it affects the number of instances you see in the model and would expect to be listed in a report (child_component.count_used_instances).

2 Likes
10

Ah. I see what you mean. The effect is the same with count_instances.

11

Resolved the issue, thanks everyone. An issue with the model I’d imported was the problem, the Ruby API is working correctly with count_instances.

12

Counting is not trivial. As Christina said, we have to (recursively) multiply with the parent’s number of instances and check whether the parent is a used component (that means whether it’s most upper parent is the model). Same considerations if you want to consider visibility as well.

1 Like
13

Hmm… that should not be the case. count_instance traverse the model hierarchy tree and count all instance - so that will be an accurate figure of how many instances are placed in the model.

14

I meant that instances.count is the same as count_instances.

Christina explained it right. count_used_instances counts the actual amount of instances in the model even if some of them are in a duplicate parent instance.

image
image579×521 7.73 KB

2 Likes
15

This topic was automatically closed 91 days after the last reply. New replies are no longer allowed.