Today’s guest post is by Alexander Schreyer, author of the Sketchfab uploader extension for SketchUp and the book “Architectural Design with SketchUp”. Alex will help you export your SketchUp scenes to Sketchfab and set up your materials and post processing for the best results.
Imagine this scenario: You have created a beautiful 3D model of a project in SketchUp and now you want to share it with a client. Of course you could send images or a walk through video. You could even send the SketchUp file but then your client needs to install at least the SketchUp viewer. None of those are as easy as sharing a web link and letting your client explore the model interactively in a browser.
That – I am guessing – led you to look at Sketchfab. And as you may know by now, I have written a handy SketchUp Extension that lets you upload your model directly from within SketchUp. If you haven’t installed it yet, open SketchUp, go to Window > Extension Warehouse and install it right from there. Then log into Sketchfab and get your API token from your account’s settings page. For more information on that process, check out the video below:
Now you are ready to upload a model. Before you do that, however, it is important to consider some basics that will at the very least make your life easier when you are fixing it up in Sketchfab. The following instructions will also help you troubleshoot any problems that you may encounter along the way.
Before you upload your model (still in SketchUp)
While you may be able to upload a well-modeled, well-organized, and clean SketchUp model without any modifications to Sketchfab, other models don’t upload easily. You might need to attempt the following fixes to prepare your model for uploading first.
Original SketchUp Model
To begin, it’s a good idea to make a copy of the original model file so that you can optimize this file for upload without messing with your work.
Although it shouldn’t influence the upload much, go to the Components window first and then to the Materials window afterwards and click on the little house icon in each to show what’s in your model. Then click on the right-arrow icon to the right of it and select “Purge Unused”. That will delete any unused items that are just bloating your file and are making it hard to work with.
Next, check that all face fronts are pointing outwards. Keep in mind that SketchUp is able to assign different materials to each side of a face – a feature that many rendering programs and Sketchfab’s WebGL technology don’t really like.
As you can see in the image below, switch the face style first to Monochrome. This will display fronts of faces in white and backs of faces in blue (and hides all textures). As you can see in the image, the front face of my house is reversed, for example. Right-click on the face and select “Reverse Faces” from the context menu to fix this.
Now switch back to the “Shaded with Textures” face style.
Next you should remove all “backface” materials. You could do that manually but there is a very nice extension, written by SketchUp’s Ruby sage ThomThom, called Material Tools, that will do it for you in one operation. Install it from the Extension Warehouse as described above. Then find the menu item Extensions > Material Tools > Remove All Backface Materials and click on it.
If this removes any visible materials in your model then that is a good indication that they were applied to the wrong side anyways. Just fix by repainting.
Your model should now be ready for upload. If you still run into any problems with it, look for ThomThom’s CleanUp3 extension (also in the Extension Warehouse) and try out some of its cleaning tools that allow you to simplify edges, faces, materials, etc.
Some other tips to consider for your model are:
- In Sketchfab, you can edit materials “by material”, not “by face”. Keep this in mind when you are adding materials in SketchUp. Also, remember that a good naming scheme goes a long way.
- Text labels, dimensions, construction-points and -lines don’t upload (this is hard-wired into SketchUp’s export function).
- Inserted images (e.g. for billboards) need to be exploded before upload so that the textures show up properly.
- Face-me components (e.g. the scale figure) lose the ability to always face the camera. Their last orientation before upload becomes permanent.
- Heavily-instanced and textured components (e.g. vegetation that contains many copies of a textured leaf component) don’t upload well because the upload process explodes the entire model. Prefer using simpler models (e.g. vegetation with only colored leaves).
Once your model has been prepared correctly, use the uploader extension as described above to send it to Sketchfab.
After you upload your model (in Sketchfab)
Your SketchUp model will now look similar to my sample raw upload on the Sketchfab website:
While you can already interact with the model at this point, Sketchfab’s strength lies in the fact that you can adjust the materials, the environment, lighting, and other parameters. You can basically set your model up like you would in a rendering program, with many of the same settings.
As you can see in my model, there are some reflective objects (the window, door, and the pool) that look flat, there are also some textures that could benefit from some depth (the stone patio and the bricks), and there is a transparent material (the fence) that is currently non-transparent. Let’s adjust those now. Under the uploaded model in Sketchfab, look for the “3D Settings” menu item.
I should mention that the following adjustments assume that the Renderer setting in the 3D Settings editor is set to “Classic”, not “PBR”. While the PBR renderer offers many exciting possibilities for adjusting materials, the classic renderer often has enough power for the typical building materials that can be found in SketchUp models. Feel free to experiment with PBR, though.
Materials that have recessed parts (like the mortar lines on a brick wall) or a surface texture (like heavily grained wood) often benefit from adding a bump map. This pushes in part of the texture and makes shadows appear. You can see the result in the image below. For the brick wall, I adjusted the settings as shown and uploaded an inverted gray scale image of the brick texture as the bump map. With those images, darker areas in them become recessed.
You can export any texture in SketchUp from the Materials window and then adjust it using Photoshop or a similar software. In Sketchfab, click on the small square icon on the left of a material setting to manage or upload any textures.
Reflections also look more realistic with a bump map, which you can see in the pool image in the following section. Given a reasonably high specular and environmental reflection value, the water ripples really come to life based on a simple pool water texture that is used as a bump map.
Transparency and Reflections
Whenever you need to modify transparency, look for the Alpha Blending value in the materials editor and adjust as needed. Edit transparency, specular, and environment reflection values until you get the desired effect. If you assign a color to those (using the picker on the left), then intensity is driven by that color, if you assign a texture, then intensity is adjusted similar to what you saw with the bump map.
One caveat with reflections is that they can only show the environment background and the lights. Don’t count on them to reflect model elements, as a mirror would.
For the fence, I adjusted the Alpha Masking setting instead of the Alpha Blending under Transparency. This will let you recreate the effect you saw in SketchUp where the texture of the fence is created by a texture image with a transparent background.
Experiment with the lighting presets in the second tab of the 3D Editor. As you can see in the image below, adding a lighting preset creates shadows in the model, which in my case provide a nice modeling light that lets the viewer evaluate materials and building features well. You can even simulate a fixed sun position using the light settings.
Picking a good environment background provides your model with added lighting as well as nice-looking reflections. While you could leave it visible, I decided in my sample to make it disappear as a background by turning “Replace Background” off.
The first tab of the 3D Editor offers several post processing options that are common image enhancements: grain, sharpening, vignette, bloom, tone mapping, color balance, even chromatic abberation (which basically adds a common lens defect). Adjust these to your liking. For my model, I added some (film) grain, a vignette (the darker edges in the image), and some bloom, which overexposes lighter areas in the model slightly.
While you will typically apply and adjust material textures in SketchUp before upload, it is possible to upload new textures to Sketchfab. Also, as appropriate, you could experiment with adding an emittance value to light-emitting materials (e.g. neon tubes).
Finally, as you may have already seen in the 3D Editor, it is possible to add annotations to the 3D model as well. This is a great feature for explaining your shared model.
The Final Model
That’s it! At this point, you have imported a SketchUp model into Sketchfab, adjusted it with some common settings, and made it look great. You are now ready to share it with a client via a URL, post it as a 3D model to Facebook, or embed it on your website.
Wait! I need more help!
I hope this post gave you some useful tips. While I am not able to go into more detail here, a good resource for learning/refreshing SketchUp techniques and understanding material/rendering parameters (and much more) is my book “Architectural Design with SketchUp: 3D Modeling, Extensions, BIM, Rendering, Making, and Scripting”, which just came out as a second edition. It’s a great reference that even comes with instructional videos. If you have a question and would like to reach me, feel free to do so anytime on my website sketchupfordesign.com.