Importing and visualizing geometry

This tutorial will show how to create a scene from scratch in appleseed.studio. We will import geometry from .obj files and visualize the imported geometry using the diagnostic rendering modes.

Table of contents:

1. Starting appleseed.studio
2. Creating a new project
3. Importing geometry
4. Visualizing the scene
5. Conclusion

A few .obj files are required to complete this tutorial; you can download them here.

1. Starting appleseed.studio

On Windows, you can just double-click on the appleseed.studio.exe file located in the bin\ directory of your appleseed installation. On Linux and Mac OS X, you'll need to open a terminal, go to the bin/ directory of your appleseed installation and run the run-appleseed.sh script.

Once started, appleseed.studio looks like this:

The user interface is made of the following elements:

• the Project Explorer (on the left by default) shows all the entities the project contains and allows to add, remove or edit entities
• the Log panel (on the bottom by default) shows all the information, warning and error messages output by appleseed.studio
• the main panel (on the right of the Project Explorer by default) contains the rendered image

Note that the toolbar (which by default sits beneath the menu bar), the Project Explorer panel and the Log panel can all be detached, moved around and docked again at various places inside the window.

2. Creating a new project

Create a new project by choosing File → New Project (keyboard shortcut: Ctrl+N):

A newly created project contains:

• an empty assembly called "assembly"
• an instance of this assembly called "assembly_inst"
• a pinhole camera called "camera" featuring a 0.980 in × 0.735 in (24.892 mm x 18.669 mm) film and a focal length of 35 mm
• a 640x480 sRGB frame

You can see the first two items by expanding the Assemblies node in the Project Explorer:

appleseed 1.1.0 alpha-5 doesn't yet allow to see the camera or the frame in the Project Explorer.

Some terminology: in appleseed, an assembly is a sort of "sub-scene". Entities in an assembly can reference (use) other entities in the same assembly as well as global entities that don't belong to any assembly, but they cannot reference entities from another assembly. During rendering, an assembly is only loaded when actually needed. It also has the capacity of being moved around, rotated or scaled during rendering; however, although this feature is supported by the renderer, it isn't made available in appleseed.studio at this point.

3. Importing and visualizing geometry

Let's go:

• Right-click on the assembly "assembly" and choose Import Objects...
• Locate the .obj files that you previously downloaded to your computer, select the files light.obj, floor.obj and killeroo.obj and open them.

You will notice some log messages appearing the Log panel each time you import an .obj file: they mention the absolute path to the .obj that was loaded, the time it took to load the file and the number of vertices and triangles that were loaded from the file.

If you expand the Objects and Object Instances nodes in the Project Explorer, you should see the three objects that were imported and the corresponding object instances:

A few more bits of terminology: in appleseed, objects cannot be rendered: they are merely a bunch of geometry but they don't have a position or any material information. Object instances are lightweight entities that reference objects and add transformation (position, orientation and scale) and material information to them such that they can be rendered. Several object instances can reference the same object but apply different transformations and materials: that's the whole point of this object/instance decoupling.

You'll also notice that the object instances appear in purple: that's because they don't have any material information yet.

4. Visualizing the scene

At this point it's useful to make sure the geometry was properly imported and that the camera is properly oriented. In appleseed.studio this can be done using the diagnostic rendering modes, without having to apply any material.

Apply the Wireframe diagnostic mode by opening the Diagnostics menu and choosing Override Shading → Wireframe. Then, render a single frame by choosing Rendering → Start Final Rendering (keyboard shortcut: F6). You should get the following result:

We're getting this result because the camera is not properly positioned and oriented, so let's fix that.

• Start interactive rendering by choosing Rendering → Start Interactive Rendering (keyboard shortcut: F5)
• Zoom out by doing Ctrl + Right Mouse Button + drag downward inside the frame
• Stop interactive rendering by choosing Rendering → Stop Rendering (keyboard shortcut: Shift+F5)

At this point you should be able to see something like this:

Let's try to have a better view at the scene:

• Restart interactive rendering (F5)
• Rotate the camera by doing Ctrl + Left Mouse Button + drag horizontally and vertically
• Move the target point (the point of interest) of the camera by doing Ctrl + Middle Mouse Button + drag horizontally and vertically
• Stop interactive rendering (Shift+F5)

You should eventually obtain a result similar to this:

5. Conclusion

Save the project to disk by doing File → Save Project (keyboard shortcut: Ctrl+S).

That's it for this tutorial. In the next tutorial, we will show how to create and apply materials to the imported geometry.

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