How do you apply a collision to a curved wall?

[Crash180]

Played with this over the weekend after making some curved walls but I can't figure out how make collisions for them. I looked at the concrete curved walls and it looks like they have a base collision with some navcuts that rotate from the radius point. Not sure how all that works. I have Blender, Nifskope and Outfit Studio for tools.

[pepperman35]

When you think of circles or circular objects think in terms of polygons.  For example, if your circular wall is based on a dodecagon (i.e., a polygons that has 12 sides) you can use a series of rectangles arrayed in a circle for the collision mesh.  Attached is an unprocessed nif to illustrate the result.  This was an example of 12 sided wall, with one side remove for entrance.  You might have to use a bit of math to determine the width of your rectangles and angles of rotation.

FO4_CircularWallTest.rar

[pepperman35]

BTW, this tutorial, while 3ds max focused, explains navcuts.  I do not know if the exporter in Blender has a similar function.

[South8028]

In 3ds, any collision is done in a couple of minutes with just a spline and edit poly. You outline the structure with a spline, grab the edge +Shift. Pull it out. Target Wild connects edges, or vertices, Cut adds edges. Blender has similar tools and it is hardly difficult to make a collision (outline an object). In Blender, you cannot add this collision to nif. But this can be done in the latest version of nifscop, as far as I heard.It is important to know that fo4 is oriented towards 3ds 2013-2014. There are official plugins for 3ds that come with ck. These plugins allow you to create any game resources. Blender doesn't have comparable capabilities in fo4.

[Crash180]

Okay. So it sounds like one of my attempts may have been on the right track. I had brought the exported nif into Outfit Studio and disassembled it by vertical loop cuts which gave me columns to convert in Nifskope with havoc. This worked but 2 out of the 12 columns produced 0 hulls and vertices which I had only encountered on flat planes like glass panes and wall panels. I just made these outline columns in Blender and Nifskope was able to convert all 12 for a nice looking collision. This works out much nicer and with less effort. Gonna have to rethink how I use Blender.

The next thought was if I had mixed materials in my wall I could just create separate outlines for them and handle them in Nifskope for their own collisions, sounds and visuals.

Thank you everyone.

 

 

[RoNin1971]

I'm a bit late, but still, my 2 cents:

Using a convex hull isn't going to work well with curves. It fills all "holes" (& inner curves). Better to use the mesh option for creating a rigid body.

I used to create curves using separate boxes combined into a single (compound) collision, as that way it works since each box gets a convex hull which matches the box. Nowadays I use a mesh more and more to create a rigid body. Frequently the same mesh as the visible object. (depending on detail). Especially walls and similar low-poly meshes can easily be used to create the collision as well.

 

As you mentioned, there is no 1:1 link between the texture/material and collision. So to get things like the sound right, you will need to cut up parts and join others. Not to mention simplifying some of it.

 

Still, I found that, at least for myself, in the end the easiest and most accurate way to get a collision is by doing just that.

 

Duplicate the meshes in Blender. Delete anything not needed (e.g. decals). Strip the material (not required), separate & join parts based on true material (metal, concrete, etc.) Simplify the mesh (less faces) if needed.

Export it to a nif. Import into 3DS, create a compound rigid body, set the type & material, export & convert it to a collision (Elric).

Instead of using a nif and 3DS, you can probably use an .obj & nifskope.