How can i make objects have a "invisible" part?

The reason some objects appear black is because the model resources don't have their alpha enabled.
There are certain objects (such as plants, vases, glass sculptures etc.) that it's enabled by default, that's why you actually see the transparency on the first object.

There is an actual way to enable it for any object you want, but it's quite time consuming (especially when you have a lot of swatches.) There is a tutorial here on the site (but it's quite outdated and that method doesn't work for me anymore) I can explain the process I follow if you want me to, or you can simply clone an object that already has transparency on it.

Alright I'll try to be as thorough as I can (since other people might want to know as well) it can get quite tedious so pay attention and read everything:

1) Go into the warehouse tab and find the "Model LOD" resources. Once you click on them you'll see that (depending on the item) there are a couple of gray shaped models and some black & white checkered ones.
The gray ones, are the shadow LODs (so we don't care about them) we only care about the black & white checkered ones.

2) Click on the first black & white checkered one, and then click on the Data tab (found on top of the preview window)

3) Once there, find the line named "Meshes" and click the "Edit Items" button.

4) A window should pop up, containing all of your mesh's groups. Choose the group you want to have the alpha enabled, and after that go to the panel on the right and scroll down until you find the Material tab.

5) There should be a line named Entries, find it and click on the Edit Items button.

6) Another window will pop up listing all the different "states" of your model. Note that the more swatches your object has, the more items will be in there and it will make the whole process a lot more tiring. I would suggest following this method with just 1 swatch, and add the other ones once you sucesfully enabled the alpha.

7) Click on the first state, go to the right panel, and click on the Edit Items button (should be the only button there, next to the line named Items)

8) Again another window will pop up. What you need to do here is to find, the line called Alpha Mask Threshold (usually at the top)

9) Click on it, and you will notice the value on the right is 0. I usually make it 100 (although some EA items can go up to 128)

10) Once you've done that, go to the left panel once again and find the Diffuse Map line. Click on it and click the blue "Copy" button at the bottom.

11) Your new line, should appear at the very bottom, select it if it's not selected, and go to the right panel. Find the line called "Field" and click on the dropdown menu. You want to change the DiffuseMap value to AlphaMap (it's around the top)

12) Once done click on the save button (bottom right) now you are back at the object states. You need to follow the steps 7-11 for ALL your different object states (that's why more swatches = more tedious work)


If you are successful your object should have its alpha enabled. But we're not done, the alpha has been enabled on the HIGH LOD only.

You need to follow these steps for all "MODEL Lod" resources, so if your object has a High,Medium,Low LOD, you should find all the three appropriate Model LODs resources (in the warehouse tab, as explained in step 1) and edit them using the steps above.

I know it's quite tiring but it's the only way (other than cloning an object that already has its alpha enabled) to do it. If you run into any issues feel free to ask.

Awesome, glad I could help you out!