{"id":50,"date":"2015-06-02T11:57:04","date_gmt":"2015-06-02T10:57:04","guid":{"rendered":"http:\/\/jenshendar.com\/?p=50"},"modified":"2015-06-02T11:57:04","modified_gmt":"2015-06-02T10:57:04","slug":"inventing-an-inventory-in-unity3d-part-1","status":"publish","type":"post","link":"https:\/\/www.jenshendar.com\/index.php\/2015\/06\/02\/inventing-an-inventory-in-unity3d-part-1\/","title":{"rendered":"Inventing an inventory in Unity3D (Part 1)"},"content":{"rendered":"

Disclaimer: I do not claim this is the best (or even a good way) to design and implement an inventory system. There is a slight (great) chance that I throughout the authoring of this post decide that ‘this is stupid’ and just scrap the system all-together and start over. If so, you’ll get your money(time) back in the form of virtual cupcakes.<\/em><\/p>\n

In this post I will try to explain the inventory system for my current lowpoly game project. A short explanation of the gameplay I’m ultimately going for is somewhat of an adventure\/mystery game. This is because I \u00a0want to keep the project on a difficulty level I can handle, therefor I\u00a0don’t want to have a combat system and as few advanced models (characters) as possible (This is the first project where I make the models mostly myself).<\/p>\n

Right now you can walk around, open a pneumatic house, pick up rocks and look out across the ocean. Epic gameplay!<\/p>\n

Here<\/a> is a demo of the current working version.
\n(Because of limitations in Chrome, you have to open it in Firefox)<\/p>\n

You move around with WASD and look around with the mouse. The pointer is locked in the middle of the screen and invisible.<\/p>\n

If you ‘look’ at something you get a small text describing what it is you are looking at (eg. “Tree”). This is done with a code similar to this (I removed some other code not needed for the inventory system):<\/p>\n

[code lang=”js”]
\nfunction Update () {
\n var ray = Camera.main.ViewportPointToRay (Vector3(0.5f,0.5f,0.5f));
\n var hit : RaycastHit;<\/p>\n

if (Physics.Raycast (ray, hit, 2)){
\n Debug.DrawLine (ray.origin, hit.point);
\n rayHitCollider = hit.transform.GetComponent(Collider);
\n switch (hit.transform.tag) {
\n case "Untagged":
\n information_text.GetComponent(UI.Text).text = "";
\n action_text.GetComponent(UI.Text).text = "";
\n action = "none";
\n break;
\n case "Item":
\n information_text.GetComponent(UI.Text).text = hit.transform.name;
\n if (hit.transform.GetComponent(Collider).GetComponent(Item)) {
\n rayHitCollider = hit.transform.GetComponent(Collider);
\n if (rayHitCollider.GetComponent(Item).ableToPickUp) {
\n action_text.GetComponent(UI.Text).text = "Pick up (E)";
\n action = "pickUpItem";
\n } else {
\n action_text.GetComponent(UI.Text).text = "";
\n }<\/p>\n

}
\n break;
\n default:
\n information_text.GetComponent(UI.Text).text = hit.transform.name;
\n action_text.GetComponent(UI.Text).text = "";
\n action = "none";
\n break;
\n }
\n } else {
\n information_text.GetComponent(UI.Text).text = "";
\n action_text.GetComponent(UI.Text).text = "";
\n action = "none";
\n }<\/p>\n

if (Input.GetKeyDown ("e")) {
\n doAction();
\n }
\n if (Input.GetKeyDown("f")) {
\n doItemAction("throw");
\n }
\n}
\n[\/code]<\/p>\n

The scripts shoots a raycast towards where the player is looking, locked to the center of the screen. If the hit of the raycast has a tag which is not “Untagged”, the text underneath the cursor changes to the name of the object and if the object type (decided by tag) has an option (eg. door->open) there is an actiontext below the cursor as well and a variable called “action” is set. If the object is “Untagged” or the raycast doesn’t hit anything the text is nulled.<\/p>\n

If you aim your mouse at something you can interact with and press “E” a function called “doAction()” is called. It looks like this:<\/p>\n

[code lang=”js”]
\nfunction doAction() {
\n\tswitch (action) {
\n\t\tcase "openDoor":
\n\t\t\tif (rayHitCollider.GetComponent(Door).doorOpen) {
\n\t\t\t\trayHitCollider.GetComponent(Door).closeDoor();
\n\t\t\t} else {
\n\t\t\t\trayHitCollider.GetComponent(Door).openDoor();
\n\t\t\t}
\n\t\t\tbreak;
\n\t\tcase "pickUpItem":
\n\t\t\ttransform.GetComponent(CharacterInventory).addItem(rayHitCollider.gameObject);
\n\t\t\trayHitCollider.gameObject.SetActive(false);
\n\t\t\trayHitCollider.gameObject.tag = "Untagged";
\n\t\t\trayHitCollider.gameObject.transform.parent = equipItemObject.transform;
\n\t\t\trayHitCollider.gameObject.transform.localPosition = Vector3(0,0,0);
\n\t\t\trayHitCollider.gameObject.transform.localRotation = Quaternion(0f,0f,0f,0f);
\n\t\t\tbreak;
\n\t\tdefault:
\n\t\t\tbreak;<\/p>\n

\t}<\/p>\n

}
\n[\/code]<\/p>\n

I’m going to focus on the inventory-action. If you are able to pick up the item, determined in the first script (a bool in the “Item” script attached to all items), the “pickUpItem”-switch case is called and a few things happen.<\/p>\n