A package that adds various tools which allow you to control forces and gravity in your unity scenes like never before!

Check out the package here: https://github.com/westonwright/forces-and-gravity-unity

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Force Producers

Force Producers calculate the force applied to a point in space depending on the type of producer.
Producers can individually apply a different type of force (Force, Acceleration, Impulse, VelocityChange) and can use additive or weighted blending to mix with other producers.
You can create arbitrary types of ‘force’ and decide how you want them to affect objects in your scene through your own code or built-in systems. These custom forces can also selectively mix with other custom forces and use Layer Masks for further specification.

All Force Producers inherit from the ‘ForceProducer’ class and have some variables in common:

• Preview

Displays a Gizmo for the producer being displayed and its falloff. Changes Color based on Force Type and if the force is enabled.

• Enable Force

Togglable enables or disables producers from applying forces.

• Force Type

Determines which force type to apply from this producer. Force Types are Scriptable Objects which give some information about how they should behave. There are 4 included with the package but it is easy to create more to fit your needs.

• Layer Mask

Which layers to apply forces to.

• Force Strength

The strength of the forces being applied.

• Importance

Used to order producers for mixing and overwriting. The order of importance is (low to high): 1 to Infinity, then -1 to -Infinity, the 0 at the lowest importance.

• Additive

Toggles if this producer mixes with other producers. If True, it will always apply its force instead of mixing with other producers.

• Invert

Toggles if the direction of force should be inverted. Can be used to push objects away instead of pulling them in.

Currently, there are 5 types of Producers in addition to the base class:

Force Surface

Creates forces based on a ‘Shape’ component. We’ll cover shapes later. Force is determined by the distance from the surface and normal data from the Shape.

Unique Variables:

• Force Range

Determines how far from the surface of the mesh the full strength force will reach.

• Falloff Range

Determines how far out falloff reaches. Falloff creates a smooth transition from full-strength to 0-strength based on distance from the producer.

Force Collider

This is functionally the same as the Force Surface but uses Unity’s built-in colliders to define its shape. This works with all types of colliders.

Force Zone

Creates a force in one direction within an area defined by a ‘Shape’.

Unique Variables:

• Force Direction

The direction in which force will be applied within this zone. Normalized at runtime.

Force Point

Applies a force towards a single point in space with an inner radius and falloff. The inner range is determined by scale.

Force Global

Creates a force in one direction for the entire scene.

(very good gif)

Unique Variables:

• Force Direction

The direction in which force will be applied within this zone. Normalized at runtime.

Shapes

Shapes are components you can add to game objects to define an area or surface where forces should be applied. Shapes can either be pre-defined 3D objects with SDF and other properties, or can be a Mesh. It should be possible to create your own custom shapes to fit your needs if necessary. All shapes handle drawing their own Gizmos and creation of Bounding Boxes for culling.

Currently, there are 5 Shapes including an unusable base class:

Box Shape

This is one of the simplest shapes. It defines a box within the scene.

Sphere Shape

This is very similar to the box shape but defines a sphere instead!

Capsule Shape

This creates a capsule shape with the same scaling rules as Unity’s capsule colliders.

Plane Shape

Creates a plane that only applies forces ‘above’ the plane.

Mesh Shape

Creates a Shape with any mesh. Meshes can be convex or non-convex, but lower poly meshes are recommended for performance.

Rigidbody Force Receiver

Attach to a rigidbody to apply forces from Force Producers in the scene.

Variables:

• Enable Forces

If this object can actively receive forces from producers.

• Ignore Layer Mask

If this object should only receive forces from producers with correct layer masks, or if it should receive forces regardless of the layer mask.

A package that contains a variety of editor tools to allow you to do some basic texture work within Unity. With one (or a few) scripts, you can draw freely on any 3D object in your scene. Features include a layer-based system with customizable brushes with full undo support. Textures can be saved, as well as brush presets for use later.

Check out the package here: https://github.com/westonwright/texturing-tools-unity

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Features

Drawing Surface

The Drawing Surface is a script you can place on any object in a scene to enable texture editing on that object. The object must have a Mesh Filter and a Mesh Collider. The drawing surface has multiple features, explained below.

Transform/Drawing Mode

While in Transform Mode, the object behaves as normal, and cannot be drawn on from the scene view.

While in Drawing Mode all transformation tools (translate, scale, rotate) are disabled, as is selecting other objects in the scene. This allows you to draw on the object unobstructed by clicking and dragging across its geometry.

Channels

Each Drawing Surface can have any number of channels that can be swapped between at will. Channels are independent collections of layers with a set resolution and are applied to the correspondingly named texture channel in the object’s material. For example, you could have one channel named _MainTex that will apply to the albedo of the object, and another channel named _EmissionMap that will apply to the emission of the object.

For most materials, the primary texture channel is named “_MainTex”, so that is the default name of a new channel.

Layers

Layers are fairly self-explanatory, although it should be noted that (for now) they are listed in the opposite order you might expect! In the current release, they come in the form of Textures and Layers, although more may be added in the future.

Layers have a standard set of controls.

1. This checkbox enables or disables the layer temporarily.
2. This checkbox locks a layer, which prevents it from being drawn on.
3. This arrow moves a layer up or down in the list.
4. This context-sensitive arrow will move a layer in or out of a folder

Textures

Textures are layers that store pixel data at the resolution defined by its channel. At least one texture layer is required to enable drawing.

Folders

Folders can store other layers and folders for easy organization. A locked or hidden folder will do the same for all of its children.

Saving

Your layer data is automatically saved when your unity project is saved.

If you press “Save Drawing As…”, you can export your final drawing as a PNG to a desired location.

UV View

The UV view displays the currently selected Channel and the UV polygon data of the selected drawing surface. It can be drawn on directly, with the added benefit of displaying in RGB when the current channel might not be on the object.

Drawing Settings

Displays which tool is currently being used and any associated settings. There are currently two tools: Brush, and Eraser

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How it Works

Spacing Stroke Points

One of the main issues that became immediately visible when first designing this system was the appearance of each stroke was directly tied to the frame rate of the engine and the speed of the cursor. The solution was to track the distance traveled since the last point and only draw a new one past a given threshold. This feature is called “Spacing” in the drawing settings and can be tuned to the desired distance or turned off completely.

This solution was not perfect, however, as when the cursor traveled further than the threshold distance in one frame, it would essentially skip any point that would have been drawn. The solution was to store new points in a queue and add multiple points to the queue if the distance traveled was too great. While not a perfect solution due to the added appearance of hard lines, it was a better solution than allowing gaps in the stroke.

Surface Drawing

Drawing on the surface of an object uses raycasts to determine the UV coordinate of the point currently being drawn. Because the basic implementation would simply draw a straight line between any two points in UV space, it would run into issues any time there was a UV break, as demonstrated below:

To remedy this, the vertex indices of the previous tri drawn on are stored and compared against those of the new stroke. If all of them are the same (meaning it is the same tri) or there are at least two matches (meaning it is a neighboring tri), the stroke can be continued as usual. If there aren’t at least two matches, the stroke interpolation must be halted and resumed at the new location. In future implementations, it is possible that a smoother line could be drawn without having to halt the stroke completely.

It should be noted that this also introduced potential issues if the distance from the last point drawn happened to skip over more than two tris. The current solution for this is to check every screen-space pixel in the line between two desired points to detect changes in the tri. This could be improved in the future with a quick-search-esque implementation of searching through the pixels or perhaps something more advanced.