voxseparate: fix uninitialized members causing segfaults

- also we now use ogt_vox_transform_get_identity() instead of explicitly defining it.

apps/voxseparate.cpp

@@ -110,21 +110,15 @@ int32_t main(int32_t argc, char** argv) {
         return 3;
     }
 
-    ogt_vox_transform identity_transform;
-    identity_transform.m00 = 1.0f; identity_transform.m01 = 0.0f; identity_transform.m02 = 0.0f; identity_transform.m03 = 0.0f;
-    identity_transform.m10 = 0.0f; identity_transform.m11 = 1.0f; identity_transform.m12 = 0.0f; identity_transform.m13 = 0.0f;
-    identity_transform.m20 = 0.0f; identity_transform.m21 = 0.0f; identity_transform.m22 = 1.0f; identity_transform.m23 = 0.0f;
-    identity_transform.m30 = 0.0f; identity_transform.m31 = 0.0f; identity_transform.m32 = 0.0f; identity_transform.m33 = 1.0f;
-
-    ogt_vox_layer default_layer;
+    ogt_vox_layer default_layer = {};
     default_layer.hidden = false;
     default_layer.name = "default";
 
-    ogt_vox_group default_group;
+    ogt_vox_group default_group = {};
     default_group.hidden = false;
     default_group.layer_index = 0;
     default_group.parent_group_index = k_invalid_group_index;
-    default_group.transform = identity_transform;
+    default_group.transform = ogt_vox_transform_get_identity();
 
     // process all input files specified
     for (int32_t input_index = 1; input_index < argc; input_index++) {
@@ -161,23 +155,23 @@ int32_t main(int32_t argc, char** argv) {
             }
 
             // if there is no model name, we either skip the export of this model (if --named-models-only was specified ) or give it an autogenerated name
-            char tmp_model_name[64];
+            char tmp_model_name[64] = {};
             if (!model_name) {
                 // otherwise, autogenerate a name for the model based on its index in the vox file.
                 model_name = tmp_model_name;
                 sprintf_s(tmp_model_name, "model%i", model_index);
             }
 
             // construct the scene with a single instance referencing this model
-            ogt_vox_instance instance;
+            ogt_vox_instance instance = {};
             instance.group_index = 0;   // default_group
             instance.hidden      = false;
             instance.layer_index = 0;   // default_layer
             instance.model_index = 0;
             instance.name        = NULL;
-            instance.transform   = identity_transform;
+            instance.transform   = ogt_vox_transform_get_identity();
 
-            ogt_vox_scene output_scene;
+            ogt_vox_scene output_scene = {};
             output_scene.groups        = &default_group;
             output_scene.num_groups    = 1;
             output_scene.instances     = &instance;