/// <summary>
/// Calculate collision
/// </summary>
/// <param name="ray"></param>
/// <param name="sphereCollider"></param>
/// <param name="result"></param>
private static void CalculateCollision(ref Ray ray, ref SphereCollider3D sphereCollider, out RayCastResult result)
{
Vector3 sphereCenter = sphereCollider.Transform3D.Position;
float sphereRadius = sphereCollider.Radius * sphereCollider.Transform3D.Scale.X / 2;
Vector3 m = ray.Position - sphereCenter;
float b = Vector3.Dot(m, ray.Direction);
float c = Vector3.Dot(m, m) - sphereRadius * sphereRadius;
// Exit if r’s origin outside s (c > 0) and r pointing away from s (b > 0)
if (c > 0.0f && b > 0.0f)
{
result = new RayCastResult();
return;
}
float discr = b * b - c;
// A negative discriminant corresponds to ray missing sphere
if (discr < 0.0f)
{
result = new RayCastResult();
return;
}
// Ray now found to intersect sphere, compute smallest t value of intersection
float t = -b - (float)Math.Sqrt(discr);
// If t is negative, ray started inside sphere so clamp t to zero
if (t < 0.0f)
{
t = 0.0f;
}
Vector3 q = ray.Position + t * ray.Direction;
Vector3 normal = (q - sphereCenter);
normal.Normalize();
result = new RayCastResult()
{
HitBody = sphereCollider.Owner,
HitData = new RayHit3D()
{
Location = q,
Normal = normal,
T = t,
}
};
}
private AxisManipulationHelper CreateHandle(AxisManipulationHelperType amhType, AxisType axisType, Prefab prefab, Material idleMaterial, Material grabbedMaterial, Material focusedMaterial, Quaternion orientation, AxisManipulationHelper[] relatedHandlers)
{
// Entity name suffix
var suffix = $"{amhType}_{axisType}";
// Handle root
var handle = new Entity($"handle_{suffix}")
.AddComponent(new Transform3D()
{
LocalScale = Vector3.One * this.HandleScale,
});
this.rigRootEntity.AddChild(handle);
if (prefab != null)
{
// Instantiate prefab
var prefabInstance = prefab.Instantiate();
var prefabTransform = prefabInstance.FindComponent <Transform3D>();
prefabTransform.LocalOrientation = orientation;
handle.AddChild(prefabInstance);
}
else
{
// Generate default look for the handle
Vector3 position = Vector3.Zero;
Vector3 size = Vector3.One;
Component mesh = null;
Component collider = null;
switch (amhType)
{
case AxisManipulationHelperType.Center:
var sphereDiameter = 1f;
mesh = new SphereMesh()
{
Diameter = sphereDiameter,
};
collider = new SphereCollider3D()
{
Margin = 0.0001f,
Radius = sphereDiameter,
};
break;
case AxisManipulationHelperType.Axis:
var axisLength = 4f;
var axisThickness = 0.5f;
size = new Vector3(axisLength, axisThickness, axisThickness);
mesh = new CubeMesh();
collider = new BoxCollider3D()
{
Margin = 0.0001f,
Size = size + Vector3.One,
Offset = Vector3.UnitX,
};
position = 0.5f * Vector3.UnitX * (axisLength + 2f);
break;
case AxisManipulationHelperType.Plane:
var planeLength = 2f;
var planeThickness = 0.25f;
size = new Vector3(planeLength, planeThickness, planeLength);
mesh = new CubeMesh();
collider = new BoxCollider3D()
{
Margin = 0.0001f,
Size = size + Vector3.One,
Offset = Vector3.UnitX + Vector3.UnitZ,
};
position = 0.5f * Vector3.Normalize(Vector3.UnitX + Vector3.UnitZ) * (planeLength + 2f);
break;
}
// Collider entity
var handleCollider = new Entity($"collider_{suffix}")
.AddComponent(new Transform3D()
{
LocalPosition = Vector3.Transform(position, orientation),
LocalOrientation = orientation,
})
.AddComponent(collider)
.AddComponent(new StaticBody3D()
{
CollisionCategories = this.CollisionCategory,
IsSensor = true,
})
.AddComponent(new NearInteractionGrabbable());
// Visual entity
var handleVisual = new Entity($"visuals_{suffix}")
.AddComponent(new Transform3D()
{
LocalScale = size,
})
.AddComponent(mesh)
.AddComponent(new MeshRenderer())
.AddComponent(new MaterialComponent());
// Build hierarchy
handle.AddChild(handleCollider);
handleCollider.AddChild(handleVisual);
}
// Apply material
var materialComponents = handle.FindComponentsInChildren <MaterialComponent>().ToArray();
this.ApplyMaterialToAllComponents(materialComponents, idleMaterial);
// Register helper object
var helperTargetEntity = handle.FindComponentInChildren <NearInteractionGrabbable>()?.Owner;
if (helperTargetEntity == null)
{
throw new Exception($"The handle entity needs to have a {nameof(NearInteractionGrabbable)} component.");
}
var handleHelper = new AxisManipulationHelper()
{
Type = amhType,
AxisType = axisType,
BaseEntity = handle,
MaterialComponents = materialComponents,
IdleMaterial = idleMaterial,
GrabbedMaterial = grabbedMaterial,
FocusedMaterial = focusedMaterial,
RelatedHandles = relatedHandlers,
};
this.helpers.Add(helperTargetEntity, handleHelper);
return(handleHelper);
}
