Models and Proxies

Creating external models and their Proxies

To keep SketchUp model sizes small and still produce very high-quality renderings, export the heaviest components (trees, cars, etc.) into external .mod.thea files and replace them with simplified ‘proxy’ versions in SketchUp. Proxies can also be created for Thea models that come from other modeling applications. This can be done in the Thea Browser. Every SketchUp component can be exported into an external .mod.thea file and replaced by an automatically generated approximation of the original. The special external model creation tool can be opened by right-clicking on a selected component and choosing the ‘Thea Render/Create external model/proxy’ option.

Creating an External Model

Click on the ‘From SketchUp’ button to obtain a thumbnail of an external model directly from SketchUp. Or click the ‘Render’ button to start a new rendering using the current engine and settings; it is recommended to choose one of the interactive rendering methods. Only a selection will be rendered. To see a preview while the rendering is still running, click the ‘Render’ button again; just a portion of the view will be shown. You can adjust the camera/sun position to achieve the best look. When you are happy with the result, you can create proxies as described below.

Creating Proxies

To create a proxy from original components, select 'Detailed proxy.' Choose between Triangles or Points, and specify the maximum number of triangles or points. On the right is the original model containing about 27,000 faces. Just below are two proxies, each containing only about 2,000 triangles or points.

If you only want to use the proxy in the current model, disable the ‘Save as .mod.skp’ option. As you can see in the bottom proxy on the right, the ‘Add the bounding box’ option was enabled. To display only the bounding box, disable the ‘Detailed proxy’ option. You can choose between replacing only the selection, or all instances of the selected component. When you click on ‘Save,’ you will choose where to save the external model and, optionally, the proxy. All textures associated with the component will be saved in the same folder. To create a proxy component from an existing Thea model, right-click the thumbnail in the Thea Browser and choose between triangles or points. When the ‘Detailed proxy’ option is enabled, you can add a bounding box if desired.

Proxy components can be also created manually in various ways, but they have to be based on proxies that were created using one of the two aforementioned methods.
The following method works especially well for trees:

  • Insert a mod.thea into an empty SketchUp model at the origin.
  • Switch to the front view and turn off the perspective view.
  • Select the Camera/Zoom tool so the entire height of the SketchUp view aligns with the proxy's bounding box.
  • Set the Thea camera to an ‘Arbitrary’ aspect ratio and adjust the resolution so that the red camera frame matches the bounding box. The larger resolution (usually vertical) can be 512 pixels.
  • In the ‘Channels’ tab, enable alpha channel and render the model non-interactively in the Thea Window.
  • Once you are satisfied with the rendering, save the image as a *.png file. The alpha channel, responsible for transparency, will be saved automatically in this format.
  • Repeat the same procedure for the side and top views.

This gives you three images, which you can then import to SketchUp and place inside the proxy component. You can explode them (turn the images into editable geometry) and delete the bounding box. Once you are happy with the result, you can right-click on the component and save it in the same folder as original .mod.thea file.

Creating proxies from FBX and Thea models

In Thea for SketchUp, it is possible to import FBX files and convert them to proxy models. While importing an FBX file, the user is able to adjust the proxy materials.

  • Start with a blank SketchUp model.
The proxy will be placed at 0,0,0 and it is better having a clean scene.
  • Go to Extensions > Thea Render > Tools > Open FBX/Edit Thea Model
  • Select an FBX file.
  • Once loaded, the Proxy Creation dialog will popup which lets you adjust proxy settings.
  • The list of materials in the drop-down of the Thea Material Editor will be populated with materials of the imported model. The list will revert back to scene's material once it gets closed.
  • Start Interactive Rendering and press the 'From Thea' button to grab a preview for the .mod.thea file that will be generated.
  • Once done, click on the 'Save' button and select a location for the .mod.thea file. Better to save the file to the same location with all the associated textures.

When Proxy Creation window closes – you will have a ready to render proxy inside SketchUp and corresponding .mod.thea on your HD.