koobas.hobune.stream
Resizing dynamically added BoxCollider to encapsulate all child objects' total bounds
I have a GameObject consisting of several children. Each child holds another set of children that contain actual meshes, but the general shape of the total object can be summed up to a box (think, chest body and lid with meshes for wood and decor).
I haven't been able to find a way to scale the boxcollider to represent the full size of the parent gameobject in world space. A lot of the answers I find solve similar issues with a Renderer component which seems deprecated.
What should I do here? (this must be added and scaled dynamically)
Only thing I can think of is to iterate all child objects, pool them into a list of renderers, then iterate the Bounds of each renderer, test outside the bounds to find the farthest bound on each side, then resize your box to match the farther bounds of all objects.
Are you referring to their $$anonymous$$eshRenderer?
That is one type of renderer. All Renderers have a Bounds property. You can generically get any type of renderer the object contains by doing
Renderer rend = GetComponent<Renderer>();
Basically to get your bounds of the final box, you would just compare 6 floats, $$anonymous$$X, maxX, $$anonymous$$Y, maxY, $$anonymous$$Z, maxZ. Test every renderers bounds to find the largest and smallest numbers of each, and then you have your final bounds. To be honest, the quickest way might be to take each renderer pisition and move out by Vector3.up someDistance and Vector3.Right someDistance etc, that way you can call the Bounds.ClosestPoint function to get the closest point after your outside the bounds, this should give you the farthest outside point of each vector. You'll just need to iterate ClosestBounds 6 times per renderer to get forward, back, up, down, left, and right.
Thanks to @RobAnthem who led me onto the right tracks. :) Here is the solution:
The parent sets up the children by calling something like
SetCollidersFrom<BoxCollider>(m_Body, m_Rotater.GetContainer());
which does
public void SetCollidersFrom<CollType>(params GameObject[] from) where CollType : Collider
{
if (!m_UseCollider) { return; }
if (from == null) { Debug.LogWarning("<color=" + DebugColor + ">" + DebugName + "SetCollidersFrom -> Invalid parameters.</color>"); return; }
int added = 0;
List<MeshRenderer> meshrend = new List<MeshRenderer>();
List<Bounds> boundsForEach = new List<Bounds>();
Bounds totalBounds = new Bounds();
int index = 0;
foreach (GameObject go in from)
{
if (!BlacklistedNames.Any(go.name.Contains))
{
var bounds = _GetChildRendererBounds(go);
boundsForEach.Add(bounds);
totalBounds.Encapsulate(bounds);
}
}
foreach(GameObject go in from)
{
if (typeof(CollType) == typeof(BoxCollider))
{
BoxCollider bc = go.AddComponent<BoxCollider>();
bc.enabled = true;
bc.size = (boundsForEach[index].size * 2) * m_ColliderPadding;
bc.center = new Vector3(0f, (bc.size.y / 2), 0f);
added++;
index++;
}
}
if (added > 0)
{
Debug.Log("<color=" + DebugColor + ">" + DebugName + added.ToString() + " colliders set.</color>");
}
}
which uses helper function:
private Bounds _GetChildRendererBounds(GameObject go)
{
var renderers = go.GetComponentsInChildren<Renderer>();
if (renderers.Length > 0)
{
Bounds bounds = renderers[0].bounds;
foreach (var rend in renderers)
{
if (!BlacklistedNames.Any(rend.gameObject.name.Contains))
{
bounds.Encapsulate(rend.bounds);
}
}
return bounds;
}
else { return new Bounds(); }
}
And the result: 
