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Placing Light Probes
Light Probes for moving objects
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Placing probes using scripting

Placing light probes over large levels by hand can be time consuming. You can automate the placing of light probes by writing your own editor scripts. Your script can create a new GameObject with a LightProbeGroup component, and you can add probe positions individually according to any rules that you choose to program.

For example, this script can place Light Probes in a circle or a ring.

using UnityEngine;
using System.Collections.Generic;

[RequireComponent (typeof (LightProbeGroup))]
public class LightProbesTetrahedralGrid : MonoBehaviour
{
 // Common
 public float m_Side = 1.0f;
 public float m_Radius = 5.0f;
 public float m_InnerRadius = 0.1f;
 public float m_Height = 2.0f;
 public uint m_Levels = 3;
 const float kMinSide = 0.05f;
 const float kMinHeight = 0.05f;
 const float kMinInnerRadius = 0.1f;
 const uint kMinIterations = 4;
 public void OnValidate ()
 {
  m_Side = Mathf.Max (kMinSide, m_Side);
  m_Height = Mathf.Max (kMinHeight, m_Height);
  if (m_InnerRadius < kMinInnerRadius)
  {
   TriangleProps props = new TriangleProps (m_Side);
   m_Radius = Mathf.Max (props.circumscribedCircleRadius + 0.01f, m_Radius);
  }
  else
  {
   m_Radius = Mathf.Max (0.1f, m_Radius);
   m_InnerRadius = Mathf.Min (m_Radius, m_InnerRadius);
  }
 }
 struct TriangleProps
 {
  public TriangleProps (float triangleSide)
  {
   side = triangleSide;
   halfSide = side / 2.0f;
   height = Mathf.Sqrt (3.0f) * side / 2.0f;
   inscribedCircleRadius = Mathf.Sqrt (3.0f) * side / 6.0f;
   circumscribedCircleRadius = 2.0f * height / 3.0f;
  }
  public float side;
  public float halfSide;
  public float height;
  public float inscribedCircleRadius;
  public float circumscribedCircleRadius;
 };

 private TriangleProps m_TriangleProps;
 public void Generate ()
 {
  LightProbeGroup lightProbeGroup = GetComponent<LightProbeGroup> ();
  List<Vector3> positions = new List<Vector3> ();
  m_TriangleProps = new TriangleProps (m_Side);
  if (m_InnerRadius < kMinInnerRadius)
   GenerateCylinder (m_TriangleProps, m_Radius, m_Height, m_Levels, positions);
  else
   GenerateRing (m_TriangleProps, m_Radius, m_InnerRadius, m_Height, m_Levels, positions);
  lightProbeGroup.probePositions = positions.ToArray ();
 }
 static void AttemptAdding (Vector3 position, Vector3 center, float distanceCutoffSquared, List<Vector3> outPositions)
 {
  if ((position - center).sqrMagnitude < distanceCutoffSquared)
   outPositions.Add (position);
 }
 uint CalculateCylinderIterations (TriangleProps props, float radius)
 {
  int iterations = Mathf.CeilToInt ((radius + props.height - props.inscribedCircleRadius) / props.height);
  if (iterations > 0)
   return (uint)iterations;
  return 0;
 }
 void GenerateCylinder (TriangleProps props, float radius, float height, uint levels, List<Vector3> outPositions)
 {
  uint iterations = CalculateCylinderIterations (props, radius);
  float distanceCutoff = radius;
  float distanceCutoffSquared = distanceCutoff * distanceCutoff;
  Vector3 up = new Vector3 (props.circumscribedCircleRadius, 0.0f, 0.0f);
  Vector3 leftDown = new Vector3 (-props.inscribedCircleRadius, 0.0f, -props.halfSide);
  Vector3 rightDown = new Vector3 (-props.inscribedCircleRadius, 0.0f, props.halfSide);
  for (uint l = 0; l < levels; l++)
  {
   float tLevel = levels == 1 ? 0 : (float)l / (float)(levels - 1);
   Vector3 center = new Vector3 (0.0f, tLevel * height, 0.0f);
   if (l % 2 == 0)
   {
    for (uint i = 0; i < iterations; i++)
    {
     Vector3 upCorner = center + up + (float)i * up * 2.0f * 3.0f / 2.0f;
     Vector3 leftDownCorner = center + leftDown + (float)i * leftDown * 2.0f * 3.0f / 2.0f;
     Vector3 rightDownCorner = center + rightDown + (float)i * rightDown * 2.0f * 3.0f / 2.0f;
     AttemptAdding (upCorner, center, distanceCutoffSquared, outPositions);
     AttemptAdding (leftDownCorner, center, distanceCutoffSquared, outPositions);
     AttemptAdding (rightDownCorner, center, distanceCutoffSquared, outPositions);
     Vector3 leftDownUp = upCorner - leftDownCorner;
     Vector3 upRightDown = rightDownCorner - upCorner;
     Vector3 rightDownLeftDown = leftDownCorner - rightDownCorner;
     uint subdiv = 3 * i + 1;
     for (uint s = 1; s < subdiv; s++)
     {
      Vector3 leftDownUpSubdiv = leftDownCorner + leftDownUp * (float)s / (float)subdiv;
      AttemptAdding (leftDownUpSubdiv, center, distanceCutoffSquared, outPositions);
      Vector3 upRightDownSubdiv = upCorner + upRightDown * (float)s / (float)subdiv;
      AttemptAdding (upRightDownSubdiv, center, distanceCutoffSquared, outPositions);
      Vector3 rightDownLeftDownSubdiv = rightDownCorner + rightDownLeftDown * (float)s / (float)subdiv;
      AttemptAdding (rightDownLeftDownSubdiv, center, distanceCutoffSquared, outPositions);
     }
    }
   }
   else
   {
    for (uint i = 0; i < iterations; i++)
    {
     Vector3 upCorner = center + (float)i * (2.0f * up * 3.0f / 2.0f);
     Vector3 leftDownCorner = center + (float)i * (2.0f * leftDown * 3.0f / 2.0f);
     Vector3 rightDownCorner = center + (float)i * (2.0f * rightDown * 3.0f / 2.0f);
     AttemptAdding (upCorner, center, distanceCutoffSquared, outPositions);
     AttemptAdding (leftDownCorner, center, distanceCutoffSquared, outPositions);
     AttemptAdding (rightDownCorner, center, distanceCutoffSquared, outPositions);
     Vector3 leftDownUp = upCorner - leftDownCorner;
     Vector3 upRightDown = rightDownCorner - upCorner;
     Vector3 rightDownLeftDown = leftDownCorner - rightDownCorner;
     uint subdiv = 3 * i;
     for (uint s = 1; s < subdiv; s++)
     {
      Vector3 leftDownUpSubdiv = leftDownCorner + leftDownUp * (float)s / (float)subdiv;
      AttemptAdding (leftDownUpSubdiv, center, distanceCutoffSquared, outPositions);
      Vector3 upRightDownSubdiv = upCorner + upRightDown * (float)s / (float)subdiv;
      AttemptAdding (upRightDownSubdiv, center, distanceCutoffSquared, outPositions);
      Vector3 rightDownLeftDownSubdiv = rightDownCorner + rightDownLeftDown * (float)s / (float)subdiv;
      AttemptAdding (rightDownLeftDownSubdiv, center, distanceCutoffSquared, outPositions);
     }
    }
   }
  }
 }
 void GenerateRing (TriangleProps props, float radius, float innerRadius, float height, uint levels, List<Vector3> outPositions)
 {
  float chordLength = props.side;
  float angle = Mathf.Clamp (2.0f * Mathf.Asin (chordLength / (2.0f * radius)), 0.01f, 2.0f * Mathf.PI);
  uint slicesAtRadius = (uint)Mathf.FloorToInt (2.0f * Mathf.PI / angle);
  uint layers = (uint)Mathf.Max (Mathf.Ceil ((radius - innerRadius) / props.height), 0.0f);
  for (uint level = 0; level < levels; level++)
  {
   float tLevel = levels == 1 ? 0 : (float)level / (float)(levels - 1);
   float y = height * tLevel;
   float iterationOffset0 = level % 2 == 0 ? 0.0f : 0.5f;
   for (uint layer = 0; layer < layers; layer++)
   {
    float tLayer = layers == 1 ? 1.0f : (float)layer / (float)(layers - 1);
    float tIterations = (tLayer * (radius - innerRadius) + innerRadius - kMinInnerRadius) / (radius - kMinInnerRadius);
    uint slices = (uint)Mathf.CeilToInt (Mathf.Lerp (kMinIterations, slicesAtRadius, tIterations));
    float x = innerRadius + (radius - innerRadius) * tLayer;
    Vector3 position = new Vector3 (x, y, 0.0f);
    float layerSliceOffset = layer % 2 == 0 ? 0.0f : 0.5f;
    for (uint slice = 0; slice < slices; slice++)
    {
     Quaternion rotation = Quaternion.Euler (0.0f, (slice + iterationOffset0 + layerSliceOffset) * 360.0f / (float)slices, 0.0f);
     outPositions.Add (rotation * position);
    }
   }
  }
 }
}

  • 2017–06–08 Page published with no editorial review

  • Light Probes updated in 5.6

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Placing Light Probes
Light Probes for moving objects
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