diff --git a/src/vobs/VirtualObject.cc b/src/vobs/VirtualObject.cc
index 3bba210..61b6a43 100644
--- a/src/vobs/VirtualObject.cc
+++ b/src/vobs/VirtualObject.cc
@@ -7,10 +7,7 @@
 #include <zenkit/Archive.hh>
 
 ZkVirtualObject* ZkVirtualObject_load(ZkRead* buf, ZkGameVersion version) {
-	if (buf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_load");
-		return nullptr;
-	}
+	ZKC_CHECK_NULL(buf);
 
 	try {
 		auto ar = zenkit::ReadArchive::from(buf);
@@ -28,10 +25,7 @@ ZkVirtualObject* ZkVirtualObject_load(ZkRead* buf, ZkGameVersion version) {
 }
 
 ZkVirtualObject* ZkVirtualObject_loadPath(ZkString path, ZkGameVersion version) {
-	if (path == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_loadPath");
-		return nullptr;
-	}
+	ZKC_CHECK_NULL(path);
 
 	try {
 		auto buf = zenkit::Read::from(path);
@@ -54,173 +48,97 @@ void ZkVirtualObject_del(ZkVirtualObject* slf) {
 }
 
 ZkVobType ZkVirtualObject_getType(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getType");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return static_cast<ZkVobType>(slf->type);
 }
 
 uint32_t ZkVirtualObject_getId(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getId");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->id;
 }
 
 ZkAxisAlignedBoundingBox ZkVirtualObject_getBbox(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkAxisAlignedBoundingBox");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->bbox;
 }
 
 ZkVec3f ZkVirtualObject_getPosition(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getPosition");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->position;
 }
 
 ZkMat3x3 ZkVirtualObject_getRotation(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getRotation");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->rotation;
 }
 
 ZkBool ZkVirtualObject_getShowVisual(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getShowVisual");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->show_visual;
 }
 
 ZkSpriteAlignment ZkVirtualObject_getSpriteCameraFacingMode(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getSpriteCameraFacingMode");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return static_cast<ZkSpriteAlignment>(slf->sprite_camera_facing_mode);
 }
 
 ZkBool ZkVirtualObject_getCdStatic(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getCdStatic");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->cd_static;
 }
 
 ZkBool ZkVirtualObject_getCdDynamic(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getCdDynamic");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->cd_dynamic;
 }
 
 ZkBool ZkVirtualObject_getVobStatic(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getVobStatic");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->vob_static;
 }
 
 ZkShadowType ZkVirtualObject_getDynamicShadows(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getDynamicShadows");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return static_cast<ZkShadowType>(slf->dynamic_shadows);
 }
 
 ZkBool ZkVirtualObject_getPhysicsEnabled(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getPhysicsEnabled");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->physics_enabled;
 }
 
 ZkAnimationType ZkVirtualObject_getAnimMode(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getAnimMode");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return static_cast<ZkAnimationType>(slf->anim_mode);
 }
 
 int32_t ZkVirtualObject_getBias(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getBias");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->bias;
 }
 
 ZkBool ZkVirtualObject_getAmbient(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getAmbient");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->ambient;
 }
 
 float ZkVirtualObject_getAnimStrength(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getAnimStrength");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->anim_strength;
 }
 
 float ZkVirtualObject_getFarClipScale(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getFarClipScale");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->far_clip_scale;
 }
 
 ZkString ZkVirtualObject_getPresetName(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getPresetName");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->preset_name.c_str();
 }
 
 ZkString ZkVirtualObject_getName(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getName");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->vob_name.c_str();
 }
 
@@ -230,25 +148,13 @@ ZkVisual const* ZkVirtualObject_getVisual(ZkVirtualObject const* slf) {
 }
 
 ZkSize ZkVirtualObject_getChildCount(ZkVirtualObject const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getChildCount");
-		return 0;
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->children.size();
 }
 
 ZkVirtualObject const* ZkVirtualObject_getChild(ZkVirtualObject const* slf, ZkSize i) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkVirtualObject_getChild");
-		return nullptr;
-	}
-
-	if (i >= slf->children.size()) {
-		ZKC_LOG_ERROR("ZkVirtualObject_getChild() failed: index out of range");
-		return nullptr;
-	}
-
+	ZKC_CHECK_NULL(slf);
+	ZKC_CHECK_LEN(slf->children, i);
 	return slf->children[i].get();
 }
 
@@ -274,73 +180,41 @@ ZkVisualType ZkVisual_getType(ZkVisual const* slf) {
 }
 
 ZkString ZkDecal_getName(ZkDecal const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkDecal_getName");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->name.c_str();
 }
 
 ZkVec2f ZkDecal_getDimension(ZkDecal const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkDecal_getDimension");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->dimension;
 }
 
 ZkVec2f ZkDecal_getOffset(ZkDecal const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkDecal_getOffset");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->offset;
 }
 
 ZkBool ZkDecal_getTwoSided(ZkDecal const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkDecal_getTwoSided");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->two_sided;
 }
 
 ZkAlphaFunction ZkDecal_getAlphaFunc(ZkDecal const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkDecal_getAlphaFunc");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return static_cast<ZkAlphaFunction>(slf->alpha_func);
 }
 
 float ZkDecal_getTextureAnimFps(ZkDecal const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkDecal_getTextureAnimFps");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->texture_anim_fps;
 }
 
 uint8_t ZkDecal_getAlphaWeight(ZkDecal const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkDecal_getAlphaWeight");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->alpha_weight;
 }
 
 ZkBool ZkDecal_getIgnoreDaylight(ZkDecal const* slf) {
-	if (slf == nullptr) {
-		ZKC_LOG_WARN_NULL("ZkDecal_getIgnoreDaylight");
-		return {};
-	}
-
+	ZKC_CHECK_NULL(slf);
 	return slf->ignore_daylight;
 }