Allow creatures to use the autogenerated collision box (feature #2787)

CHANGELOG.md

@@ -149,6 +149,7 @@
     Feature #1617: Editor: Enchantment effect record verifier
     Feature #1645: Casting effects from objects
     Feature #2606: Editor: Implemented (optional) case sensitive global search
+    Feature #2787: Use the autogenerated collision box, if the creature mesh has no predefined one
     Feature #2847: Content selector: allow to copy the path to a file by using the context menu
     Feature #3083: Play animation when NPC is casting spell via script
     Feature #3103: Provide option for disposition to get increased by successful trade

apps/openmw/mwphysics/actor.cpp

@@ -6,6 +6,7 @@
 
 #include <components/sceneutil/positionattitudetransform.hpp>
 #include <components/resource/bulletshape.hpp>
+#include <components/debug/debuglog.hpp>
 
 #include "../mwworld/class.hpp"
 
@@ -28,6 +29,31 @@ Actor::Actor(const MWWorld::Ptr& ptr, osg::ref_ptr<const Resource::BulletShape>
     mHalfExtents = shape->mCollisionBoxHalfExtents;
     mMeshTranslation = shape->mCollisionBoxTranslate;
 
+    // We can not create actor without collisions - he will fall through the ground.
+    // In this case we should autogenerate collision box based on mesh shape
+    // (NPCs have bodyparts and use a different approach)
+    if (!ptr.getClass().isNpc() && mHalfExtents.length2() == 0.f)
+    {
+        const Resource::BulletShape* collisionShape = shape.get();
+        if (collisionShape && collisionShape->mCollisionShape)
+        {
+            btTransform transform;
+            transform.setIdentity();
+            btVector3 min;
+            btVector3 max;
+
+            collisionShape->mCollisionShape->getAabb(transform, min, max);
+            mHalfExtents.x() = (max[0] - min[0])/2.f;
+            mHalfExtents.y() = (max[1] - min[1])/2.f;
+            mHalfExtents.z() = (max[2] - min[2])/2.f;
+
+            mMeshTranslation = osg::Vec3f(0.f, 0.f, mHalfExtents.z());
+        }
+
+        if (mHalfExtents.length2() == 0.f)
+            Log(Debug::Error) << "Error: Failed to calculate bounding box for actor \"" << ptr.getCellRef().getRefId() << "\".";
+    }
+
     // Use capsule shape only if base is square (nonuniform scaling apparently doesn't work on it)
     if (std::abs(mHalfExtents.x()-mHalfExtents.y())<mHalfExtents.x()*0.05 && mHalfExtents.z() >= mHalfExtents.x())
     {

components/resource/bulletshape.hpp

@@ -26,8 +26,7 @@ namespace Resource
 
         btCollisionShape* mCollisionShape;
 
-        // Used for actors. Note, ideally actors would use a separate loader - as it is
+        // Used for actors. mCollisionShape is used for actors only when we need to autogenerate collision box for creatures.
-        // we have to keep a redundant copy of the actor model around in mCollisionShape, which isn't used.
         // For now, use one file <-> one resource for simplicity.
         osg::Vec3f mCollisionBoxHalfExtents;
         osg::Vec3f mCollisionBoxTranslate;