Group or Component
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My $0.02.
Components and groups serve most of the same purposes.
Rule of thumb...... One such object in a model can be either a group or a component; whereas 2 or more copies of the object must be a component, especially if you may change its geometry later on.
Grouping components can have an advantage over making a bunch of components a component.
If the bunch of comps is a comp, then you can copy it multiple times, and any (and all) edits of any one is applicable to all.
But a group of comps has an advantage over a comp of comps, in that the comps in a group can change positions, orientations and other attributes without impacting any other group of the same (or more or less the same) set of comps in it.
Example.
In my airplane designs for (say) a landing gear assy. all the bits are comps.
But the overall assy of these comps is a group. That way I can show the LG in various conditions of retraction, extension, compression and angles of deployment, with the various comps, such as hyd cylinders, struts etc. "mechanically" linked.If I change the length of a hyd. cyl. or tire diameter, then that change ripples through all the groups in their various positions. However if I change the extension of that cyl. (and adjust the relative positions of the other comps) then only that group is affected.
I do this a lot to visualize complex moving parts and their relationship to other parts at various positions of movement. If an interference shows up at say, the 3rd position, requiring a part to be modified, all the same other parts in the other positions change as well.
I put each of the groups on separate layers, as well as some of the parts on separate layers, so that I can easily see/compare positions.
I can explain this further if anybody wants.
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JGB that is all true, however, if you use a component of components rather than a group of components you can easily make copies and Make Unique the ones you want to behave differently, while still retaining the benefits of components.
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Box
Yes that is true, but if that unique comp is indeed unique, it makes little difference if it is a comp or a group.Goto the Warehouse and look at my model of the AB-609 Tilt-Rotor. Notice the multiple copies of components/groups for the engines and props or cabin in different positions, and the layers that control the visibility of those groups. Those overall groups could be unique comps, but to what advantage?
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Great thread...
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Interesting how a rather simple question can lead to such a lengthy discussion. One which doesn't have a definite ending. There doesn't seem to be a wrong or right answer, just different approaches to the same end. Producing that which is seen in the minds eye.
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@jgb said:
Goto the Warehouse and look at my model of the AB-609 Tilt-Rotor. Notice the multiple copies of components/groups for the engines and props or cabin in different positions, and the layers that control the visibility of those groups. Those overall groups could be unique comps, but to what advantage?
What I learned from this thread was that as Dave pointed out, if you make a mistake and delete a unique component there will be a copy in the component browser, with a group that would not be true.
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@gussnemo said:
Interesting how a rather simple question can lead to such a lengthy discussion. One which doesn't have a definite ending. There doesn't seem to be a wrong or right answer, just different approaches to the same end. Producing that which is seen in the minds eye.
So far this is only 1 page....
Other "simple questions" have gone on for many pages.
That's the beauty of SketchUcation.
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@jgb said:
Box
Yes that is true, but if that unique comp is indeed unique, it makes little difference if it is a comp or a group.
Those overall groups could be unique comps, but to what advantage?Components have many properties and uses that groups don't have.
Components can glue to, cut through, they can be worked on in another file and reloaded, they can be saved for latter use and placed in libraries. You can copy a component off to the side, scale it up, work on it and delete it and your original has been edited too. When you make an array of components they are all the same until you choose to make them unique, so you can make a motorway of streetlights but only make a few fall over, then if that motorway is a component you can make a second one, make it unique and change a few more streetlights.My point may not be relevant to your specific model but there is simply no advantage to not using components that I can see, with the possible exception of having to click the dialog box to create it.
Looking at your tilt model, which is BA-609 not AB-609,you have three cabin interiors which could be copied off to the side so that you could work on them comfortably without them being stacked on top of each other. The various tilt positions of the rotors could be laid out for display. Basically if you have only used components you can explode the model easily so that you can dissect its individual parts while retaining the original intact. Then any alterations you make to the exploded parts are repeated in the original.
I may be wrong, perhaps there are benefits to nesting withing groups rather than components, but I have yet to hear of any.
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You should bullet that list Box.
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In terms of efficiency components win without a doubt.
In terms of multi-app data exchange the groups win.
Horses for courses.
That being said there's a 51kb file somewhere on the forum by Alan Fraser the is heavily component-assembled that completely buckles SU.
Use with care. I did lots of tests with the 3D tree pack I made and in the end kept the branches as raw geometry.
When I had 4 components of each branch type arrayed, scaled etc SU performance dropped. When I exploded and made all the branch geometry 1 component SU was fine.
Components are great but heavily nested arrayed components can causes issues.
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Yes indeed, deep nesting can cause problems, but to the best of my knowledge those problems are not reduced by using groups rather than components.
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It's not about solving a problem but preventing them.
A cube could be 6 square faced components wrapped as a component then arrayed. Then wrap the array and array the arrayed component etc...
That's a problem.
Try making a sphere from the minimum amount of faces as components. SU chugs.
As I said components are great. But application needs to be considered.
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I'm not questioning the fact that using too many components can cause problem, I'm just pointing out that the use of too many groups can be just as troublesome but without any significant benefits.
My only point being that in my own personal view it may as well be a component even if there is only one because it has useful properties besides being able to multiply.
The discussion is about the advantages or disadvantages of one over the other, rather than the potential downside of using too many of either. -
Point taken.
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this sort of sums it up for me as far as my component vs group..
this is the end of the first phase of drawings.. space usage/flow/layout/etc -- all the objects are just shells with none of the structure.. i've used 4 component definitions and 66 groups in the model.
in contrast, here's a drawing of a single structure with all the framing instead of just a shell.. it contains 8 groups and 47 component definitions..
for me, i just use components when i need components.. otherwise, i use groups.
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Box
As an aside, the AB or BA-609 is now the AW-609.
AB was Agusta-Bell and BA was Bell-Agusta. Using AB or BA depended on which side of the Atlantic you were on (Italy or USA).
However Bell divested its share of the partnership and Westland (British) picked it up, so now it is the AW-609. The aircraft is in final certification testing, and due (way overdue) to be certified late this year or early next.
As far as group/comps are concerned, either can be copied to the side and worked on or looked at. I do this a lot, especially if a comp to be edited is deeply buried in other geometry.
However unless the various combinations of parts are properly nested (within separating groups/comps) and visibly separated by layers, you cannot compare various sets to find interferences or commonalities. You need the freedom to do both.
Again, I agree that comps overall are "better" than groups, and unique comps. can in most cases replace a group, but all 3 have unique attributes that are useful when needed.
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There is one other thing that differentiates components from groups. This was tested a long time ago in the original SketchUp forum when this recurring discussion came up. Layers and Layer0 was next most common.
SU is a database of linked objects.
A component is a SINGLE definition of a bunch of objects in the database.
Multiple copies of that comp are simply lookup pointers to the original comp definition in the database. That's why a change to any one copy of a comp. will affect all other copies.
A group is also a definition of a bunch of objects, but each multiple occurrence in the model is a separate definition in the database. That's why a change to a group does not affect any other same group copies.
That is also why a lot of the same groups make for a much bigger database file than a lot of the same comps.
When SU wants to display a group, it has the definition in the database right at hand. Takes nearly no time to compute the display.
When SU wants to display a comp. it has to go and lookup the definition each and every time to display it. That takes a bit more time plus the display time.
That is why a very small model with a lot of one component will take a longer time to display than a large model with the same number of objects as groups.
Like I said before, and as others said too, use groups or comps according to the attributes you need.
One is not "better" than the other unequivocally. -
I only mentioned the BA AB thing because a search of the warehouse using the name you listed found nothing. So I had to search for you then look for the revevant model.
Nice model it is too. -
My simple question has spawned a very interesting, and informative, discussion.
My primary use for Sketchup is to create objects which I can then import into Bryce. The objects can be created using other programs, but I find I can create them quicker using Sketchup.
It was good someone brought files sizes, because large files can help to increase render times in Bryce. I also have to be mindful when applying material in Bryce because sometimes a object, which was created in parts, doesn't import into Bryce with those same individual parts. So it is necessary to make sure when an entity is made a component, or group, they import into Bryce the same. Which isn't something which has been previously brought up.
Whether an entity is created as a component or group, it must also be taken into consideration if the model is likely to be imported/used in another 3D program. Because I'm only able to afford the free version of Sketchup, exporting using .dae enables me to import the same into Bryce because Sketchup.dae format is listed in Bryce's import list. And so far, my creations have imported into Bryce with only minor modifications. And yes, I know about the Object exporter plug-in, but it's use has caused me problems when importing into Bryce. But is this the case for other 3D programs? I use few others, so I don't know. Yet, this too much be considered.
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.......Added to what all have said, It helps me save the elements in my design for later use in my components folder.
R
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