Use Sketchup DAE for mesh/model?

[Robin23 Dagostino]

I have been using Sketchup for building models for other stuff and I know that in SketchUp I can export a model as a DAE (Collada) file.

The question is, is it really possible to upload such thing into Second Life? I haven't tried it but I saw that the Upload dialog expects .dae files. Has anyone done that with SU?

[Pamela Galli]

Yes, quite a few ppl are building in SU and importing into SL. If you do a search there was a thread with instructions within the last few months.

[Josef Munster]

Its a 2 step process, There's several reasons reasons for this even though SketchUp is Collada compliant and can produce Collada files.

First, you need to export the file to upload as an obj file from SketchUp. If you use the SketchUp free version, get and install the SketchUp obj export plugin that adds obj export to SketchUp.

Second, use MeshLab a free file converter to convert the obj file to to Collada. At this point you can upload the dae file using the viewer.

SketchUp's collada and google earth export has some conflicts with what the Second Life upload expects. SketchUp after the first release of v 7 exports Collada v 1.4.1 and Second Life uses 1.4.0. If you do get a SketchUp collada to upload, curved surfaces appear distorted. If you export to obj then use MeshLab to convert to collada, you don't get the distortion, and most important - the file uploads, and it's more efficient in terms of prims, prim equivalent, physical weight, and render cost.

In one test I uploaded two mesh files. The first one was a Sketchup v 8 exported collada (7 prims, 5 prim equivalent, 5.2 physical weight, 324 render cost). The second one was the same model exported as obj then converted using MeshLab to collada (1 prim, 3 prim equivalent, 3.0 physical weight, 55 render cost). There's no curved surface distortion  and connecting surfaces align. In other words what you uploaded in Second Life looks like what you have in SketchUp.  Also note it saves you 6 prims, 2 prim equivalent, 1.8 physical weight, and 269 render cost.

 

[ryusho Ort]

ok, what you said is true, after Meshlab, the LI is does indeed reduce significantly. However I have a question here: the texure alignment is off when I tried to upload into SL, though it looks right in Meshlab. Any idea?

[Chosen Few]

While it is technically usable, Sketchup is among the very worst of the worst of all possible choices.  It offers absolutely no way to control the topology or UV layout of your models.  It's a toy, not a tool; there's a HUGE difference there.

Do yourself a favor, and learn to use a proper 3D modeling program.  If you learned Sketchup, you can learn something else, too, so don't be intimidated by the fact that other programs can do so much more.  Whether you're swimming in a kiddie pool or swimming in an ocean, you still swim in just the few feet of water that are immediately around you.  The actual process of swimming is identical in both (as is the process of drowning).  The only difference is the ocean has a whole lot more to offer.

If you just want to do the kind of extrusion modeling that Sketchup does, just about every 3D modeling program in the world can do it, just as easily, if not more easily, than Sketchup can.  But you'll also be able to control the topology and UV layout, so you won't end up with a mess.  Not only does that mean your models will be cleaner and will perform better in any realtime environment, it also means their land impact in SL can be kept to an absolute minimum.

You'll also find that once you dare to venture past simple extrusions, there are all kinds of other methods that make the modeling process even better and easier.  You'll naturally learn these as you go, and before you know it, you'll be producing things in minutes that might have taken hours to do in Sketchup.

Ditch the toy, get a tool, be happy.

 

Here's a story that might help illuminate the problems with Sketchup.  A while back, I was hired to take over the content creation for an OpenSim-based project, for a large high-tech manufacturing company.  Before they brought me on, the management consultants they'd hired to head the project thought they'd save money by grabbing a bunch of Sketchup models for furniture, props, etc.  The simulation was riddled with problems, and some of the people involved were convinced it was because the version of OpenSim they were using must be borked or something.

Well, it wasn't long before I discovered the real cause of the issues.  Those Sketchup models were completely unsuitable for use in a realtime engine. 

The first example was in the form of a couch that they asked me to texture.  I was horrified when I brought it into Maya, and saw how it was put together.  First, it was 70,000 polys, when all it really needed was about 700.  Yes, it was literally 1000 times too heavy!  Second, and arguably important, given the way SL/OpenSim streams data, the UV setup simply could not have been worse.  It consisted of hundreds of individual UV sets, and thousands of tiny islands.  Almost all of the islands were tangled messes, spewed all over the canvas.  Needless to say, it was completely untexturable.

So, I said to the management consultants, "This 'free' couch model is going to cost your client about $600 by the time I spend the amount of hours that will be necessary for cleaning it up to make it work properly, or I can just make one from scratch right now, in about an hour, and it will work just fine."  Needless to say, they went for option B.

There's no way any human being, even the most insane, masochistic, delusional, or just plain stupid, would ever produce a UV mess that elaborately awful.  It would take literally days of dedicated work to pull it off.  Clearly, the problem was that the software that had been used to build it whacko.  The person who made the model was probably blissfully unaware that topology needs to be a consideration, or that UV's even exist.

And that was just one model, among hundreds of such models the project managers had placed all over the sim.  Not all of them were as bad as that couch, but a great many were.  A few were workable, but not many.   I ended up having to replace about 85% of them.  And guess what, the simulation ran just fine after that.

In their quest to save money by raiding the Google 3D warehouse, those project managers almost torpedoed their own project.  By the time I'd dug them out of the hole, they ended up spending more than they would have if they'd just hired me to create sensible content in the first place.

My own experiments with Sketchup have confirmed the hypothesis.  The results it produces are quite often simply ridiculous when you examine their structure afterward. 

[Angela410 Telling]

Dear Robin. First of all may I thank you for your very informative article on the limitations of Sketchup. I think you might have saved myself and others a lot of wasted time and effort. The thing that attracted me to Sketchup was that after a quick look at their first tutorial I was immediately able to create complex and meaningful designs, I could do this straightaway. I have tried, and given up on, Blender several times because I found it incredibly complicated, very beginner-unfriendly, and just too hard to understand. Sketchup works for a novice straight out of the box. Perhaps when I feel I am comfortable with Sketchup I will have another go at Blender or something similar. Thank you again. Angela

[Phedra Villota]

 Hi Robin! 

Reading what you wrote about Sketchup I was wondering what you thought  the best program to use was? I hear a lot of positive feedback for Blender and thats what I'm leaning towards learning . 

[Coby Foden]

[Kwakkelde Kwak]

Any proper 3d program will do. So Maya, 3ds Max, Blender, Cinema 4D, Rhinoceros will all work fine. All have their advantages and drawbacks.

If you are only going to use it for SL, Blender is probably your best choice. Not only is your investment minimal (it is free), most people here on the forums use it for SL, so you are likely to get the most feedback when you run into an issue or when you have some questions.

If you want to take your models to the next level with realistic normal mapping, sculpting programs like Mudbox, ZBrush or Sculptris (free), preferrably in combination with a bamboo pen, are very helpful (and a lot of fun to work with). Blender has a built in sculpt function as well.

[ChinRey]

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Chosen Few wrote:

While it is technically usable, Sketchup is among the very worst of the worst of all possible choices.  It offers absolutely no way to control the topology or UV layout of your models.  It's a toy, not a tool; there's a HUGE difference there.

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No, it's not a toy. SketchUp can be a really useful and powerful CAD application.

But there is a huge difference between CAD (Computer Assisted Design) and virtual world modelling. When you work with CAD, you usually only have a single object and it doesn't matter if it takes a minute to render, so poly count/land impact doesn't really matter much. In a virtual world you have hundreds of objects displayed at the same time and they have tor ender in real time - or as close to real time as possible. That means we have to make each model as simple as possible.

SketchUp doesn't take that into account. It makes rather messy and heavy meshes because that works well enough for what the program is itnended to be used for. It is possible to clean up a SketchUp generated mesh to make it workable in SL but generally it's not worth the time and effort.

[Sarahbuxso]

ACTUALLY - I think Sketchup does a very good job, its not messy at all when importing to blender. It divides the mesh nicely, I think they have done improvements to Sketchup since it was first introduced. Give it another chance.. its actually amazing!