Basic concepts and primitives


In this article, we look at some terms that may occur when working with editors for the first games about Harry’s adventures. Hmm. How much geometry 😉

Primitive (geometric primitive) is a simple model, a three-dimensional geometric shape (cube, cone, sphere). It is used to create more complex objects.

Surface is usually the outer side of the primitive. The cube has 6 of them. More complex shapes have much more. Hollow geometric primitives are also characterized by internal surfaces.

Cube is a geometric primitive. It is used to create rooms, locations in general, cubes for solving puzzles, simple models (cabinets, trimmed bushes, suitcases with flat surfaces).

Cylinder is a geometric primitive.

Sheet is a geometric primitive. Flat plate. It is used to create non-basic walls, platforms for jumping.

Cone is a geometric primitive.

Volumetric is a geometric primitive. It is used to create simple models of bushes. For example, in the HP2 there are simple tree models that consist of two flat primitives.

Tetrahedron (Sphere) is a geometric primitive that tries to imitate a sphere. But, in fact, it is a polygon.

Curved Staircase is an example of creating a template based on simple geometric primitives.

Spiral Staircase is an another template based on geometric primitives.

Linear Staircase: another template.

BSP based terrain is an object for creating complex surfaces, such as hills, mountains, lowlands.

Mover is a model usually derived from one or more primitives. The main feature: for it, you can set several positions in space to switch between them. It is used to create opening doors, mechanisms and any movable structures.

Projection is the definition of what a scene will look like if you look at it from a certain angle. The editor provides access to the top projection (Top view), front projection (front view), side projection (side view).

Texture is usually a graphic image (sometimes a set of images) placed on the surface or surfaces of a primitive or model. Usually, if the texture size is smaller than the surface size, then the texture is arranged in several rows until it completely fills the surface.
Animated textures (for example, water textures) can be flat shapes with many surfaces with ordinary textures applied to them.

Package is a file with a complex structure (usually binary). Allows storing textures, sound fragments and other resources in an ordered form.

Actor is a complex model that can contain a set of built–in complex motion animations (Harry, Ron, Hermione) or simply represent furniture elements, triggers and other elements that can be added to the scene.

Scene this is usually understood as a level fragment. It has quite a lot of meanings.

Collision occurs when the surfaces or internal frames of two or more models come into contact.

CutScene is a special scenario according to which the game engine builds and displays pre–staged scenes in real time, where actors act without player intervention.

PatrolPoint. A set of these actors allows you to set the trajectory of minor characters (controlled by a non-player).

Camera is a special object of the game. Through it, the player sees the game world.

Trigger. In this editor, it is a sensitive element that can trigger various game mechanisms. Example: a spell trigger reacts to an attempt to cast a spell, a musical trigger plays the specified melody if it is disturbed (for example, to pass through it).

Build (Level Assembly) is the process of creating a game world (or part of it) using models and primitives involved in the level. It may include: building movement paths (by patrol points, for example) non-main characters, building a lighting map, calculating the boundaries of game zones and much more.

Saving a level is writing a level to disk as a file.

File Types

unr these are package files containing game maps (levels) of the game. It usually does not contain textures, sounds, or other resources. If you make changes to the level map files, then your mod is unlikely to be compatible with other mods.

utx these are package files for storing textures. In no case, do not make changes to other people’s texture packages, it’s better to make one, but your own.

uax are package files for storing sounds (voiced replicas, sounds).

u these are package files for storing program classes, models, special sounds for them and textures. Models and textures, in the form of actors, are added to the “actor tree” by the editor itself. There are programs for viewing and exporting the contents of these packages (import in such programs is usually not available). Changing the contents of standard packages is highly discouraged – compatibility problems will arise for users of mods (analogous to the “hell of function libraries (dll)” for programmers).

int this is a text file containing a game script or settings. Changing the main scenarios of the game will lead to compatibility problems for users of mods.

Note: files with extensions u, unr, utx and some others have a similar structure, so in some games you may find, for example, an unr file that contains textures and sounds.

Implicit keyboard shortcuts and mouse movements for the editor (may not work in some editors)

Left mouse button + mouse movement: move along the x,y coordinates and rotate the camera left-right.

Right mouse button + mouse movement: camera rotation.

Left and right mouse buttons + mouse movement: move left-right, up-down.

CTRL+ALT+SHIFT + mouse movement: the ability to select several elements of the scene at once.

Sources of information: memories from a school geometry course, the results of communication with editors, conversations with Koops1997, UnWorld.