Entities relationship - Sketchup Ruby SDK

nicholas_yue

Hi,

I have a scene where I have created two boxes.

--The following is done via Ruby--
When I list the entities in the scene, I get all the individual faces.

Is there a property on those entities/faces (or a method/algorithm) to find out which object (box) the face/entity belongs to?

Regards

Dan Rathbun

Did You group the boxes, and then give each group a name ??

nicholas_yue

@dan rathbun said:

Did You group the boxes, and then give each group a name ??

No, I didn't

I am working on an exporter and need to deal with scenes as is rather than require the plugin user to change their work flow.

I am kind of re-building a scene representation from a polygon soup.

Dan Rathbun

Well then unless the "boxes" have been grouped or made into a component... then they are nothing but primitives that happen to share vertices.

nicholas_yue

@dan rathbun said:

Well then unless the "boxes" have been grouped or made into a component... then they are nothing but primitives that happen to share vertices.

Hi Dan,

Thanks for the advisory.

As you can see, I am new to Sketchup's workflow and best practices.

If I understand correctly, it is reasonable to expect some group/component from proper Sketchup usage.

Regards

Dan Rathbun

@nicholas_yue said:

If I understand correctly, it is reasonable to expect some group/component from proper Sketchup usage.

Well.. yes, if the user wants to treat the collection as an entity,.. give it name so it can be found, or have that name when it's exported,... make it easy to move, or scale the "group".... and have the faces in the group inherit a color and/or material en masse (by assigning them to the group in one step. Otherwise you have to assign them to each individual face.)

thomthom

@nicholas_yue said:

@dan rathbun said:

Did You group the boxes, and then give each group a name ??

No, I didn't

I am working on an exporter and need to deal with scenes as is rather than require the plugin user to change their work flow.

Normal workflow would be to group or make components out of objects. In which case you can get the name. group.name and componentinstance.name, componentinstance.definition.name.

TIG

If you simply can't group/component the boxes' geometry [which would be a logical step when making them!]... BUT they are separated by 'gaps' then if you take a face or an edge you can use .all_connected - to get an array of all faces and edges connected to the face or edge. So if you know that there are just two separate sets of geometry in the same context that will be connected to each other, then make a list of all entities - say...
ents=Sketchup.active_model.entities

then take
box1=ents[-1].all_connected
to list all edges/faces connected to the last entity in the model... then
box2=[] ents.each{|e| if not e.all_connected.include?(box1[0]) box2=e.all_connected break end }
Now box1 and box2 are arrays of the two 'separate' sets of geometry. If you just want just the boxes' faces then filer the arrays for e.class==Sketchup::Face etc...
Note that this will fail IF there's any other geometry or objects in the SKP...

nicholas_yue

@tig said:

ents=Sketchup.active_model.entities

then take
box1=ents[-1].all_connected

to list all edges/faces connected to the last entity in the model... then
box2=[] ents.each{|e| if not e.all_connected.include?(box1[0]) box2=e.all_connected break end }

I tried but it get's really slow with very large scene.

I am after a more direct way to find out
(1) How many objects are in the model
(2) For each object, what are the faces, edges, vertex

I am doing this to write out the information as a text output so I can render it in Renderman.

Is there an easier approach for folks writing exporter for SketchUp, I had a look at some of the example exporter and they don't look straight forward.

thomthom

@nicholas_yue said:

(1) How many objects are in the model

If you mean "objects" as in groups or components, that is easy. Use model.definitions to access that. But if you mean "objects" as in clusters of connected meshes which isn't connected, then TIG's way is the only way to do it.

Dan Rathbun

@nicholas_yue said:

I am after a more direct way to find out
(1) How many objects are in the model

Sketchup.active_model.entities.count
also:
model.number_faces

thomthom

@dan rathbun said:

@nicholas_yue said:

I am after a more direct way to find out
(1) How many objects are in the model

Sketchup.active_model.entities.count

That only returns the number of entities in the root context, entities inside groups and components are not counted.

Dan Rathbun

Yep.. and doesn't account for other kinds of things that would likely be exported, like: Layers, Materials, Colors, Scenes, Styles, AttributeDictionary etc.

Basically all the collection counts need to be summed, together with model.entities and definitions.each.entities, but it may be possible to use ObjectSpace.each_object to get raw numbers, rather than iterating the model DOM... but only ONE model must be open, or the numbers are worthless.

nicholas_yue

Thanks for all the suggestions, pointers and tips.

I am making progress exporting both raw entities and entities within components instances (including the transformation)

It's not complete yet (some instance are place wrongly) but I should be able to figure the rest out (might be group handling etc)

Thank you once again.