Importing OBJ Models

Import lets you place a real object into the scene instead of simple cubes and planes — a building facade, a stage set, an art object — and then arrange fixtures on it. Light Stream accepts models in *.obj and *.fbx formats; they can be prepared in any 3D editor — 3ds Max, Blender, SketchUp, and others.

An imported model is a set piece: it doesn't light up on its own and doesn't send Art-Net. Only fixtures and splines linked to a mapping light up; the model exists so you can see what the fixtures are mounted on, and so you can position them precisely along its edges and corners.

How to Import

Open the menu File → Import → 3D model (fbx, obj). The Import Object button on the toolbar of the 3D View window does the same thing — it's the third button, right after the two "magic" buttons.
In the file selection dialog, choose an *.obj or *.fbx file. Only one file can be selected at a time; to assemble a scene from several models, repeat the import.
Click Open. The model is added to the scene immediately, with no further questions or settings. A large *.fbx file doesn't load instantly — while it's loading, the cursor turns into an "hourglass".
Hover the cursor over the 3D View window and press Z without selecting anything — the camera will frame the entire scene, including the new model.

The program remembers the folder you imported from last time and opens the file selection dialog there next time.

Import cannot be undone with Ctrl+Z. If the model doesn't come out the way you expected, select its objects in the 3D Objects window and delete them with the Delete key (this action can be undone), fix the model in the 3D editor, and import it again.

What Appears in the Scene

The model isn't added as a single piece: the file is broken down into separate objects, and each one becomes a row in the 3D Objects window with its own name, its own visibility checkbox, and its own properties.

What's in the file	What it becomes
A named object or group	An Object in the scene — a part of the model. The name is taken from the file: whatever the part was called in the 3D editor, that's what it's called in the 3D Objects list.
Lines (edges not belonging to surfaces)	A spline in the scene. This is how a model arrives with ready-made lines for linear fixtures and string lights: there's no need to trace them by hand.
Materials from the accompanying file	The object's color and texture, in the Material section of the Properties window.

In addition, single fixtures — light sources placed in the 3D editor — come in from an *.fbx file. In other words, a model can arrive with fixtures already placed, and all that's left in Light Stream is to link them to a mapping.

How the model is split into objects depends entirely on how it was assembled in the 3D editor. A sensible split follows meaning: "facade," "roof," "left column," with lines for fixtures as separate objects with clear names. A model made of a single solid piece will also be a single row in the 3D Objects list: you won't be able to hide or highlight part of it. For more on preparing a model, see the article Подготовка модели в 3ds max.

Each object gets its own center — it's placed in the middle of the part, and the part rotates and scales around it. The position of the parts relative to each other is preserved: the model appears in the scene fully assembled, at the coordinates recorded in the file.

Materials and Textures

OBJ doesn't store colors and textures in the model file itself, but in a separate material file next to it; textures are separate image files as well. That's why the model must be copied and shared as a whole folder: an *.obj file on its own, without the neighboring files, will come out gray.

From the material, the program takes the base color and the base texture. It looks for the image by file name — first next to the model, and if it's not there, in all nested folders — so the usual layout of "model with a textures folder next to it" works fine.

A single scene object can have only one material. If several materials are assigned to one part in the 3D editor, it will get just one in Light Stream: to have parts of a piece be different colors, split it into separate objects by material.

Everything that came from the file can then be edited manually in the Properties window, Material section: Color, the Enable Texture checkbox, the Open button to choose a different image, and Glow — the object stops being shaded and is drawn at full brightness, as if it were glowing on its own (this is how signs and screens are done). Color is applied to all selected objects at once, so you can recolor the whole model in a single action.

Size and Orientation

Coordinates are taken from the file as-is, with no unit conversion. The Light Stream scene is measured in millimeters: one length unit in the file equals one millimeter — exactly the same as the unit used for the dimensions of primitive shapes (a cube with parameters of 1000 is a one-meter cube). A model exported in meters will end up a thousand times smaller than it should be in the scene and get lost next to the fixtures.

In the Light Stream scene, the Z axis points up. If the 3D editor exported the model "up along Y," it will lie on its side in the scene.

Both can be fixed right in the program: select all parts of the model in the 3D Objects window (click the first row, Shift + click the last one) and set a common scale or rotation for them using the Scale and Rotate buttons on the 3D View toolbar. Several selected objects are scaled and rotated as a single group, around a common center — the model won't fall apart. But if the model is going to be used in other projects too, it's more reliable to fix the scale and orientation in the 3D editor and import it again.

What to Do Next

Lock the Model: In the Properties window, an imported object has a Lock parameter (in the General section). A locked object can't be selected with the mouse in the scene — the model stops "sticking" to the cursor, and a selection box only picks up the fixtures you're placing on it. A locked model can still be selected via its row in the 3D Objects list.

Place Fixtures on the Model: Turn on Snap to Vertices on the toolbar — the points of splines you draw and the fixtures you drag will snap to the model's vertices, so a linear fixture lands exactly on the facade's edge instead of "by eye". See Добавление 3D сплайнов.

Link Objects to a Mapping: Splines that came from the file, and single fixtures from an *.fbx, aren't linked to anything at first and don't light up — in the 3D Objects window they have an empty Mapping column. Either assign a fixture to each one manually, or move them to a mapping with the Magic 2D Button — it creates fixtures on the Mapping plane and immediately links them to the objects. See Связь 2D и 3D.

Remove What You Don't Need: The checkbox in the 3D Objects list turns off the visibility of a part that's blocking fixtures from the current viewpoint; unnecessary parts of the model are deleted with the Delete key.

The Model Inside the Project

After import, the geometry is stored in the project file itself: the source *.obj or *.fbx is no longer needed, and the project will open on another computer without it. Textures, however, are stored as a link to the file — if you're sharing the project, collect it with the File → Collect Project command: it will copy all the files in use into a single folder and rebuild the paths.

Keep in mind that a heavy, highly detailed model increases the project file size, the time it takes to open, and the load on the graphics card while working. Small details aren't needed for previewing animation — it's better to simplify the model before it goes into the project.

If Something Went Wrong

What you see	What's going on
Nothing appeared in the scene	The model may have landed far from the origin — press Z in the 3D View window without selecting anything, and the camera will frame the whole scene. If no objects were added to the 3D Objects list either, the file has no named objects at all: re-save the model from the 3D editor so its objects and groups have names.
The model has holes, some faces are missing	The program reads triangles and quads; more complex faces are skipped. Triangulate the model before exporting — this operation is available in any 3D editor.
The model is gray, without textures	There's no material file or image files next to the model file. Copy the model together with all its neighboring files and import it again, or assign the texture manually in the Properties window with the Open button.
The model is lying on its side	It was exported "up along Y." Rotate it 90° around the X axis in the scene, or re-export it with the Z axis up.
The model is huge or imperceptibly small	The units of measurement didn't match at export. Set a scale in percent for the selected objects, or re-export the model so that one file unit equals one millimeter.
Lines for fixtures came in broken into fragments	This happens when a line is assembled in the 3D editor from separate segments that aren't connected to each other. Join them into a single polyline before exporting.
Splines and fixtures from the model don't light up	They aren't linked to fixtures on a mapping yet — see Связь 2D и 3D.