Terrain and shapes

Three components here are drawn through a list of points: a Sprite Shape, a Line and a Polygon. The points are in the node’s own space, so moving, turning or scaling the node takes the whole shape with it. You shape all three the same way.

A Line or a Sprite Shape needs two points and a Polygon three, and a press of Delete over a point leaves it at least that many. The arrows beside each point in the Inspector move it earlier or later in the list, and the bin removes it. A Line and a Polygon show as soon as they have their points. A new Sprite Shape shows its edge art, the preset’s one plain white band along its line; its fill is off until you tick Fill in its Fill fold.

A ledge built by hand is two things kept in step: a collider, and a row of sprites for the art. Move one without the other and the grass floats above the ground. A Sprite Shape is one line of points that makes the edge art, the fill under it and the collision, so there is only one thing to move.

The Sprite Shape preset comes with a Collider on the same node. Keep it: the Collider says whether the shape is solid, one-way and on which layer, and the Sprite Shape gives it its outline.

Which art goes where

A ledge’s top, its underside and its walls are different drawings, and what tells them apart is the way each part of the line faces. Under Art, each entry in Edges is a picture and the range of directions it is for, in degrees, from From up to but not including To. Zero faces right, 90 faces up, 180 left and 270 down.

A To smaller than its From wraps round through zero, as the right wall’s does. An open line faces up when it is drawn from left to right, which is how most ledges are drawn. If your ledge comes out as a ceiling, press Reverse. A closed shape is turned the right way round for you.

• When two ranges overlap, the first in the list wins. Reorder the list to change which.
• When a direction is in no range, that part of the line draws no art at all. A hole in the terrain is how you find a gap in your ranges.
• Size is one picture’s length along the edge by its depth into the shape. The art is laid as one band along the line, bent through every curve and mitred at every joint, so no gap opens where one straight run meets the next. Along each stretch that takes the same picture it repeats a whole number of times, each a little wider or narrower than its Size, rather than cut short. A turn sharper than 120° splits the band, each side ending square.

Corners work the same way for sharp turns. Where the line turns by more than Corner Threshold degrees and an entry in Corners covers the turn, one corner picture replaces the ends of both edges, and the band stops square on either side of it. It is chosen by the direction halfway between the two edges, so the top-left corner of a platform is 135. A turn no corner covers is bent through by the band, as a gentler one is. A Smooth shape has no corners.

Collision

With Collide ticked, the line is the Collider’s shape. It is made of boxes laid along the line, each Step units long and Thickness units deep into the shape. A shorter Step follows a slope more closely, for one more box to check. Surface Offset pushes the collision out from the line, for art that stands above it.

A character walks on a Sprite Shape’s collision in the editor’s Play and in an exported game, just as it does on a tilemap’s.

A Line draws a stroke through its points: a rope, a hanging cable, a pipe run, a beam. It only draws. Nothing collides with it.

A Polygon fills the outline its points make: a pool of water, a slope of scree, a hill in the backdrop. It can be any shape that does not cross itself, and the editor cuts it into triangles for you.

Like a Line, a Polygon only draws. To make it solid, put a Collider on a node over it.

Under a Polygon’s rows, Make a Mesh replaces it with a Mesh of the same triangles, whose points you then colour and map one by one; one undo puts the Polygon back. A MultiMesh draws the Polygon or Mesh on its own node at each of its placements, all in one draw: grass over a hill, which the Scatter brush paints.

A torch that reveals a dark room, a keyhole, a spotlight: each shows some sprites only inside a shape, or only outside it. A Sprite Mask is that shape. It never draws itself. Sprites that read it draw only where it is, or only where it is not.

Two masks on one channel add together, so a room lit by three torches is one channel and three masks. Only Sprites read masks; shapes, lines and tiles ignore them.

Three crates stacked on one another are three sprites, and each sorts on its own. Something passing at the wrong layer can end up drawn between two of them, as if it went through the stack. A Sorting Group makes everything under a node sort as one thing.

Untick Enabled to see what the group was fixing. Groups do not nest: the nearest enabled group above a node is the one it sorts with. The group covers the sprites, shapes, lines, trails, sprite shapes, polygons, meshes and words under it, in the editor and in exported games. A tilemap’s tiles and particles are not grouped: under a group, they still sort for themselves.

Under a parent with Sort children by Y ticked, a group sorts by its own position, as one figure among the room’s, and its Depth is dimmed there. What is under it still draws as one, so nothing of another figure comes between a body and what it carries.

Worlds and Levels builds Hollowmere with the shapes on this page. Hills draws its hills and a ravine’s lips as Sprite Shapes, Water and stone a cliff and a mere as Polygons, Made to measure a sky and banners as Meshes, and The meadow grass as a MultiMesh. Stacked and grouped makes carts of Sorting Groups, and In the dark shows a crypt by a lantern’s Sprite Mask. The Sprite Shape, Polygon, Sprite Mask and Sorting Group pages list every field they have.