Some questions about mesh and collision

[Section_31]

Greetings Imperial,

I have some questions regarding mesh and collision, well, a lot actually but I'll try to keep them simple. I am not exactly new to 3D modeling (had several courses but mostly for (small) engineering design, and old game years ago), however NifSkope and Blender look somewhat alien to me. I figure that before I ask the questions, it'll be better to explain what I try to achieve, therefore I shall provide a picture as example:

The above picture is original Oblivion Cheydinhal bridge. I'm assuming that I intend to do the followings:

1. Cut/remove all the supporting columns under the bridge to half of their height.

2. Remove the "old collision" for the deleted (in other words, non-existent) columns.

3. The bottom part of the column mesh is hollow (one can see through the inside of the column), therefore I'd like to place a "cover" on it (was it called face?)

4. Get textures to properly "attached" to the new modified column meshes.

Now I know in normal circumstance, one can just lower the bridge in CS rendering half of the columns unseen. But it's not the case here, I intend to work on some other meshes too, some of them will be facing horizontal and/or bigger in scale therefore "burying" them to the ground is not the solution. I have tried to modify one mesh in Blender but it's somewhat frustrating and I can't seem to get it correctly.

As for the questions:

1. Is it possible to do what I intend as listed above in NifSkope? Or do I have no other choice but to use Blender?

2. The method I use for deleting the part of the mesh followed similar procedure here. I click all what I deem as necessary vertices then erase them. I remember that in my courses with the old engineering 3D design software, I can make a box (or other shape) that act like "eraser" or deleter therefore I can quickly delete part of the mesh without having to click every single vertice. Is it available in Blender? How?

3. I'm using similar procedure on the same section to cover the hollow (SPACE → Edit → Faces → Make Edge/Face ). Is it the only way?

4. I have no clue how to attach textures in Blender, and still somewhat confused with placement of texture in NifSkope (I managed to replace some mesh's texture with a new one but that's just about it). Can you guide me through both?

Your help will be very precious.

[PacificMorrowind]

As for the questions:

1. Is it possible to do what I intend as listed above in NifSkope? Or do I have no other choice but to use Blender?

technically you can delete vertices/faces in nifskope but it is about as fun as hitting darts in the dark at a dart board you don't know where its . to make new faces you do need a modeling solution - Blender fits nicely.

2. The method I use for deleting the part of the mesh followed similar procedure here. I click all what I deem as necessary vertices then erase them. I remember that in my courses with the old engineering 3D design software, I can make a box (or other shape) that act like "eraser" or deleter therefore I can quickly delete part of the mesh without having to click every single vertice. Is it available in Blender? How?

Yes, (in edit mode) press B once then select a box or press B twice to have a "paint brush" style curser to just grab lots of verts. then press X or delete. However in this case you probably just want to select the 6 (guessing) verts at the bottom of the colomn and then move it up the z axis rather than delete them.

3. I'm using similar procedure on the same section to cover the hollow (SPACE → Edit → Faces → Make Edge/Face ). Is it the only way?

again use the B key to select the whole new facial area then I suggest pressing Shift-F - usually will work, if not you will have to manually make faces.

4. I have no clue how to attach textures in Blender, and still somewhat confused with placement of texture in NifSkope (I managed to replace some mesh's texture with a new one but that's just about it). Can you guide me through both?

I can texture fine... not well but reasonable but can't really explain it. However Vince has some lovely tutorials - named session 1 and 2 - in the modeling classroom, and they answer pretty much everything in this post... go read them for a better grounding.

[Section_31]

Thanks, PM (can I call you PM?). Didn't know about 'B' feature before. Sorry if I wasn't clear before, when I said box I mean making a 3 dimensional cube that can act as remover. The 'B' helped, but I wonder if I can do the "cube remover"?

And yup, yup, yup. I already read all professor Vince's tutorials, including the Textures101, got copy of them all on the HD. In fact, one of the method I used was Knife Cut mentioned in page 13 of Session 2 (but it's somewhat prone to "unsmooth cut" like when making a line that might not be perfectly horizontal or vertical) . I'm quite understand about texturing and managed to get a working normal map for flag textures using Paint.NET some times ago. I am however, still confused with something like UV. For example, when I right click a mesh's surface in NifSkope then select Texture → Edit UV, I see white lines and dots. I can move them, but have no idea how they got wrapped like that or a particular texture was applied on this style, etc.

[PacificMorrowind]

Yep PM's fine (also go by with different people as PacMo, Pacific... as long as I can recognize that its refering to me i'm fine).

The B key is three dimension (goes backward in a straight line forever) unless you have hide background geometry active - in which case it will only select what you can see in that square. So try turning of occlude background geometry (it's the square icon next to where you select whether you want to select faces, edges or verts - have it unclicked, that would be popped out).

For the knife cut try centreing you view with view front/side/top, and then if necessary rotating with the numpad arrows keys 90/180degs to go to the other side/back/bottom... if you're viewing the geometry not straight on most things in Blender won't make the nice straight edge you often want because it draws lines in relation to your view.

Editing the UV in nifskope is horrific if you're moving more than a couple verts. Blender's uv isn't bad, and if you select sync UV & Mesh selection you can get a better understanding of how the mapping works by selecting a few faces at a time on the mesh or uv map and seeing where those faces are on the other. the U key will give you a basic UV map for new models but for an existing model such as the bridge yuo are best editing it.

Pacific Morrowind

[Section_31]

I have some more questions.

1. How do I modify the existing collision to match the actual mesh shape? Can it be done automatically in Blender or is there some specific procedure for collision? In this case, the collision for column also get shorten to half.

2. If I want to make circular hole on the bridge roof, or supposedly for simpler example, something like this:

Is it possible to make a long tube that cut through the center part of a block? I haven't figured out how to do this, because the method I used so far was by clicking the vertices or edges for rectangular shape, but what if I want to make circular hole?

3. Using Cheydinhal bridge image as example, if supposedly the bridge was only built half (the vertical blue line on the render screen represent the 'imaginary line' where only part of the bridge to the left of it is built, while to the right of the line there was no any bridge/mesh). How do we make a similar duplicate that can snap edge-to-edge with the original and then combining them into a single mesh?

Pheeww...that's a lot, time to take a deep breath...

[PacificMorrowind]

I have some more questions.

1. How do I modify the existing collision to match the actual mesh shape? Can it be done automatically in Blender or is there some specific procedure for collision? In this case, the collision for column also get shorten to half.

ask away... answers: in this case the best thing is just to manually edit the collision, just select the collision mesh (in Blender) and edit it like any other mesh... blender treats it as such except for a few settings assigned to the mesh. For simple things/small things you can use the editmode->mesh->scripts->hull command to good effect but for something like this you really just need to manually create (or edit in this case) a collision.

2. If I want to make circular hole on the bridge roof, or supposedly for simpler example, something like this:

Is it possible to make a long tube that cut through the center part of a block? I haven't figured out how to do this, because the method I used so far was by clicking the vertices or edges for rectangular shape, but what if I want to make circular hole?

circles are not the easiest but the best way to create that would be select the face you want on both sides of the mesh, now in the buttons window (or by keycode W IIRC) hit subdivide a few times. then select a octagon or hexagon worth of faces top and bottom, hit delete->faces. then select the edge verts there (top and bottom) and hit SHIFT-F now it may or may not generate the faces correctly - if so you'll see a hexagonal hole, if not it will basically replace the faces you just deleted or do something weird. If did soemthing weird you'll have to manually generate the faces by select two top and two bottom verts and hitting f and then doing it again and again until you've circumnavigated the hole. Now select hose 6 or 8 faces and in mesh options in the buttons window hit "set smooth". now it'll appear as a round hole.

3. Using Cheydinhal bridge image as example, if supposedly the bridge was only built half (the vertical blue line on the render screen represent the 'imaginary line' where only part of the bridge to the left of it is built, while to the right of the line there was no any bridge/mesh). How do we make a similar duplicate that can snap edge-to-edge with the original and then combining them into a single mesh?

Pheeww...that's a lot, time to take a deep breath...

well that depends on the part that is built ie the bottom wouldn't make the top easily haha. but say it was the right half, the best method would be measure the distance from the far right to the left edge of the mesh. now select all verts (in edit mode) and hit duplicate verts, then DON'T move your mouse but press enter, then hit M(mirror) and the axis to mirror on (in this case Y), then hit enter, then move it exactly the number you measured earlier on the axis. then hit Crtl-N (recalculate normals outside) and then the joining lines and hit remove duplicate verts, you should then remove X number of verts... if no verts are removed you didn't measure or enter your number accurately enough. That should work... I've done it on some armour pieces, but no guarantees on this.

Pacific Morrowind

[Arthmoor]

Oh, nice, B key, where have you been all my life!

Seriously, that just saved me a big fat hassle for cutting arwelkyndarch01.nif into two pieces. Can you believe Bethesda didn't give us the two halves standard? They add so much character to an Ayleid ruin.

[Phant0m32]

1. How do I modify the existing collision to match the actual mesh shape? Can it be done automatically in Blender or is there some specific procedure for collision?

2. Is it possible to make a long tube that cut through the center part of a block? I haven't figured out how to do this, because the method I used so far was by clicking the vertices or edges for rectangular shape, but what if I want to make circular hole?

In reference to your first question:

I would recommend reading THIS wiki article on collision meshes.

I also thought PacificMorrowind's Blender collision TUTORIAL was useful too.

As for your question about cutting a circular hole in something, I have done this using the boolean modifier in Blender. HERE is a link to the Blender Manual section for it.

[Section_31]

Thank you very much all! Your help is very precious! All people who have replied to this thread (PM, Arthmoor, Phant0m32) and shall have their names be put into acknowledgments section on my upcoming plugin(s)! (Actually I already put Arthmoor name in the Beth thread for helping me on some CS basic, but still... )

Anyway, if I may add, during my search for guidance, I stumbled upon a very precious UV editing (texturing) guide in Blender by pekka. Then, I discovered a Blender video tutorial about a tip of hole cutting on curved surfaces (although I must say that the link to Blender Wiki provided by Phant0m32 is exactly what I was looking for).

I also had problems with ZeroDivisionError: float division in which Blender failed to export modified meshes into Nif format, but after searching I got some insight from Nifstools forum about it here and here. No clear solution, but I just used the old method of removing potential problematic faces and rebuilding them, Blender exported successfully again for me. Well, the more meshes I am working upon, the more I discovered oddities, I currently have one regarding texturing, but since this thread is mainly about mesh and collision and there is a sub-forum already dedicated for Texturing I shall post there. Again, thanks for all your help!

[PacificMorrowind]

I also had problems with ZeroDivisionError: float division in which Blender failed to export modified meshes into Nif format, but after searching I got some insight from Nifstools forum about it here and here. No clear solution, but I just used the old method of removing potential problematic faces and rebuilding them, Blender exported successfully again for me. Well, the more meshes I am working upon, the more I discovered oddities, I currently have one regarding texturing, but since this thread is mainly about mesh and collision and there is a sub-forum already dedicated for Texturing I shall post there. Again, thanks for all your help!

Please give me one of the error messages you are getting. I just (4 or 5 days ago) ran into that same error code but different place - it can be any place there is division if there isn't a safety check first. I fixed the one I got and my fix is going into the next version and I'd happily give it a try on yours - since it is a different one I can tell just from what you did to fix it.

I'll go see reply to your texturing question.

Pacific Morrowin

[Section_31]

Here are the error messages I kept getting before I did the old school method of deleting the faces.

Frankly, I still have no idea why this occurred on the first place and then why it suddenly gone. However, one of the users at Nifstools forum did similar method to solve this which also strangely worked, therefore I decided to do the same.

[PacificMorrowind]

well that isn't as nice of an error message as I got - those lines don't have any division anyways so but I went through and removed a few possible zero division locations - here's an updated file - if you want you can grab that (just extract to your blender/.scripts directory) and test and if not no problem.

Pacific Morrowind