Oolite Bulletins

Staer9 wrote:

That is the long-extinct pre-2.5 version of Blender,
Where did you download it?

it's always worth getting the latest build from http://www.blender.org/download/get-blender

(especially seeing as the latest version is 2.63a)

No wonder. I thought it looked a bit archaic. I just installed it using Terminal, but they must not have the newest version as part of the software package. I'll get the newest. Thanks.

This is eerie. I feel like the only one that posts here anymore.

Ahem, anyway, I've got this model issue, you see. It showed fine in Blender, with no holes, no normals to flip, and painted up pretty decent. When I got it into the game, though, it shows a hole right through from back to front, like it would be if the normals were off. I don't know what to do if they are, because they don't show up like that in Blender. Here are some pics.



Notice that this one was taken in Object Mode, and when there are flipped normals they have always showed up for me here.



Once more, in Edit Mode, painted, and showing no holes.



There on the left rear of the ship is a hole you can see through and view the system sun. What is happening here, does anyone know? Thanks.

I've seen this happen with some of my models too, in blender select those polygons that are getting flipped in oolite and triangulate them, do this inside blender rather than letting the obj2dat script try and do it, as it looks like the script is getting a bit confused and flipping the normals so that they point into the object rather than outwards.

What might be causing it in your ship model is two verticies really close (or even on top of each other), check that area to see if when you select what looks like one vertex, the current selection info is showing that you have actually got two or more verticies selected, if so try and 'weld' or 'merge' them together.
there's a post here that explains how to weld verticies http://blenderartists.org/forum/showthr ... tolerances

Try not to have too many 'ngons' in your final .obj object that you send to the script ('ngons' is a generic term for any polygon that has 5 or more verticies in it), save out a version in which you try and get everything down to mainly 3 and 4 point polygons (blender may have some selection options that lets you quickly select all polygons with more that 4 verticies, once you have these selected triangulate them, then check the edges are flowing properly, and if not, select then spin them like we saw in the other thread)

edit: i saw this written on a forum "In a BMesh Build, you can select Ngons by going to Select in the 3D View header, picking "By Number of Verts" from the list, and in the Tool Pane (or the F6 menu) picking "greater than" for the Type and 4 in the Number of Verts." I don't have Blender installed so i'm not sure if that's right, but it may help get you on the right path to hunting down and triangulating your ngons!

Nice ship design by the way, hope you get these issues fixed as it'll look great in game!

Thanks Griff. I think I have been missing a fundamental that most of you seem to possess, and I didn't get. Are ALL faces suppose to be triangles? I did as you said, and there are no doubles, or vertices bunched together, especially in that area. In fact, the faces that seem to be flipped are both triangles on the ship. I messed with the positioning of several vertices, so it has a smoother look in object mode, but I don't understand the triangulation you speak of. Kind of dense, I know, but that's the way I tend to be.

The ship is a knock off of the "Flying Sub" from TV series "Voyage To The Bottom Of The Sea". I took it's general shape, and made a spaceship out of it. It looks a lot like the Flying Sub, but I changed several things on it, and made no real attempt to completely duplicate it.

Graphics cards "generally" prefer to operate mathematically on triangles (for lots of reasons) - so even though we talk about "polygons" (i.e. many sided) we don't really mean it - however complicated your model is, it will need to be divided up into triangles at some point. Obj2dat is supposed to do that but it can get it wrong - if you do it in Blender you have more control and you can see the effect it has on your model inside Blender and tweak vertices accordingly/appropriately if necessary.

In the other thread where I no longer visit, I did ask you about excessive triangulation through what I presumed was an intended symmetrical nose->tail axis on one side compared to the other. You stated something like "I rather like the effect" - I thus presumed you had done it intentionally and I had affronted you by effectively picking on your design choices. Based on the question you've now asked Griff, I am now assuming you've left your model untriangulated, using what ever polygon shapes they happen to be and allowed Obj2dat to do the best it can.

It would be interesting for you to perhaps go back and traingulate all of your old models just to see if some of the aberrations go away because you're no relying on Obj2Dat to do the job.

Yeah, you're right, I didn't understand. I am now working on the present model, and have triangulated the whole model in Blender. I'm not sure how it will turn out, but it will be an education. As for going back to all my other models, that may be a while. Once more, if I insulted you with my ignorance, and short temper, I apologize.

mandoman wrote:

I am now working on the present model, and have triangulated the whole model in Blender. I'm not sure how it will turn out, but it will be an education. As for going back to all my other models, that may be a while.

Please also take a look at Ahrumans post -> https://bb.oolite.space/viewtopic.php?f=4&t=12165. It's probably time to switch the converter tool (to Obj2DatTexNorm.py) as well...

Okay. Thanks Svengali.

I tried using the Obj2DatTexNorm.py, and all I got was a blank page for the .dat.

I got a successful .dat file from the Obj2DatTex.py, but even though I almost completely redid the ship, that hole remains. I converted all faces to triangles, and checked for doubles, as well as flipped normals. Blender is just not showing a problem where the game is. I don't get it.

Just checking that you flushed the cache when you restarted the game - otherwise Oolite will see the ship is the same as before you redid it and not update the internal model with the new one...

(We still need to do that, yes? - he asks one of the Devs...)

Yeah, that's pretty much systematic for me, any more. I lots of times hold the Shift key down, even when there isn't something new. Just now, before I checked my e-mail, I reconstructed the area that was showing the normals flipped, and when I finished I started all over with a new .png, and .dat. Never got to the .dat. Right in the middle of using the paint texturing tool, the color changed in mid spray from the bright yellow I wanted, to a dull yellow, and I could swear it was getting darker as I went on. So I quit. I'm not sure if I'm losing it, or if there is something happening in Blender that I just don't understand.

Not sure how Blender renders it's lighting (I don't use it as I have access at work to AC3D, Studio Max and Creator) but "getting darker" implies to me that that section isn't being lit the same way as the surrounding area - this to me implies - despite what you think about the normals you are somehow colouring "the other side" of the polygon - i.e. away from the light which is illuminating the rest of the model.

Perplexing and I don't know enough about Blender to help.

Oh, okay. Actually what you said reminded me of something I tried, but didn't undo. I used "Shade Smooth", which made the model LOOK like it was all smooth, and curvy, but it didn't make a lick of difference when exported. Hmm, now to undo that mess. Sheesh, I just keep digging myself in deeper on this one. Serves me right.

I vaguely recall the trick with smoothing is to do it using the Oolite game engine lighting model. You do this by splitting the model (in the dat file post creation) into areas - certain areas you leave alone, others you set to smooth and Oolite shades across the polygon in a way that makes the surface look (more) smooth without adding any extra polygons to the model.

Sorry I'm being a bit vague - Ahruman spent much deep sighing trying to explain it to me - if I can find the posts I will link to them here.