Layers vs. Groups

I started using Layers once I started building some bigger models, and I found them to be quite useful in order to break things up (basically to hide, en masse, the same areas) allowing me to focus on one particular area or another.

Then as I used more components, I noticed the group functionality, and at first I was confused about the relative uses of layers, groups and components. Why did the Sketchup team include all three ways of linking together elements?

Then I was introduced to the Outliner, which I consistently but mistakenly refer to as the organizer, because that is what it does so well (see last week’s post). At first, once I discovered groups, I completely eliminated the use of layers.

Now I feel like I have come up with a good division of labor between groups and layers (and components). In the screen shot shown, you can see how I use the three. You can see that the master bath is a group (highlighted in blue). Then, for houses, I always have the same four layers: Layer0, Lot, Fixtures and Furniture. 'Layer0' (white) is the default for anything I hand draw. 'Lot' is for the earth and terrain that surround the house (not shown; for many people the lot would simply be a flat rectangle representing the garden or "lawn"). Then I have 'Fixtures' (red) and 'Furniture' (green), both of which include the components I've used. (Components assigned to the Fixture layer stay put, and those in the Furniture layer can be rearranged).

The advantage of relegating the lot and the components to their own layers is that when making macro changes to the structure of your house, with a few clicks you can quickly clear the clutter away. With them hidden it also really helps with performance because it reduces the slow orbiting and panning that occurs in large and complex models.

In summary:

Layers - Use these to hide elements that you don't need to see all the time
Groups - Use these to organize your model, breaking it up into smaller pieces
Components - Use these for items that you reuse repeatedly in your model, like chairs or toilets

I [heart] the Outliner

I look at a lot of models in the 3d warehouse, and download and view many of the full house models, particularly when they include interiors.

One thing that I'm repeatedly amazed by are complex models (as full houses always are) that are completely flat model structures, meaning a series of components surrounded by lines and faces with no groups or model specific components.

A friend of mine ran a marathon in four hours, and had a chance to mingle with the other runners. He said to the 1st place finisher, "I have no idea how you can run 26 miles in under two hours." And the winning runner said back to him, "I have no idea how you can continue to run for four hours straight."

This is what I think of when I see these models with no groups. I have no idea how anyone creates a full house (or any complex model) WITHOUT heavy use of grouping and then organizing those groups with the Outliner, while maintaining their sanity.

In my opinion, using the Outliner is critical, allowing you to break a large model into a series of smaller models, as shown in the image. It also allows you to make better use of components and as always, using good quality names for the objects in your model will help enormously.

For a great introduction to using the Outliner, please view Aidan Chopra's video on youtube, "Putting it all together, after the jump.

In my next tips and tricks post I will talk about using groups in conjunction with layers.

Next Project - Sneak Peak

My next project is a more traditional colonial, one that is more the taste of my girlfriend then mine. However, despite its staid exterior I will be adding some fun and unique features to the interior.

Here is a sneak peak of the rough model until it is completed.