What Are VTube Split Bends?

What is a Split Bend?

To handle a 180-degree or greater bend, VTube has to split the bend into two half-angle adjacent bends to form the XYZ centerline. This is why it VTube calls this situation a Split Bend.  The Split Bend idea solves the issue where two parallel lines in a bend never intersect. When importing a model, VTube operators understand that a 180-degree bend must be handled this way.  

Split Bend method can handle any bend angle up to 360 degrees (not-inclusive).  So, if a model has a 190-degree bend, then Split Bend will handle that bend also.

While it is not required, Split Bend can be used for bends that are less than 180-degrees. In many cases, a part with a high-degree bend angle (135 degrees or greater) can be inspected better if you choose to turn that bend into a split bend.

How is the Data Formed with Split Bends?

When two bends form one larger Split Bend, VTube will continue to show the two separate bends in the XYZ centerline data grids, but will combine the two adjacent angles into a single bend angle in the LRA grid below.  LRA grids show an row as orange in the LRA grid when that row (straight) is considered a Split Bend. When that happens, the number of LRA rows are reduced by 1 for every Split Bend active in the part.

Without Split Bend on, this part appears to have 5 straights.  But you can see that VTube represents the 180-degree bend as its own straight.  In this first image, Split Bend is not activated.

However, it is best to treat the last two adjacent 90-degree bends as a single Split Bend - because the bender will consider these two bends as one large 180-degree bend. (If you are using VTube-LASER, then measuring a Split Bend using the special Split Bend measure process is very important).See how a Split Bend is activated i this video:

Now the LRA grid will change like shown below. But also note that the XYZ centerline data never changes.

How to Import a Model with a Split Bend

VTube also needs to know when a part of the model should be handled as a Split Bend.  When you import a model with 180-degree bend, then you will need to follow these steps using Collect Control.

1 - Use Collect Control to collect Straights from Cylinder Surfaces up to the first 180-degree bend.

2 - Since this video shows the "Keep adding more surfaces" option active, collect all the regular straights first.  Every 180-degree bend is considered its own straight, so increment the straight in the Collect Control when passing over a 180-degree bend.

3 - Select the "Split Bend Surface" option in the Collect Control spinner.

4 - Change the straight number to match each split bend you collect.  In this part, the 180-degree bends represent straights 2 and 6.

5 - Rebuild the parametrics. 

See this video to learn how to import a model with 180-degree bends.