Rolling Stock skinning ideas

Creating and Editing Rollingstock
nedfumpkin

Re: Rolling Stock skinning ideas Unread post

I came across this site that has a ton of pictures that you might find helpful with the heavy coaches. There are profile and end pics galore. Most are in black and white.

http://www.imagescn.technomuses.ca/railways/index.cfm
nedfumpkin

Re: Rolling Stock skinning ideas Unread post

Grand Trunk RR, wooden carriage from 1895....
WPandP

Re: Rolling Stock skinning ideas Unread post

Okay, just to let everybody else get a sneak peak, here's what I've been working on lately. It'll be included as part of an overall update to the Express Cars mod that I've already released; I still need to make a few tweaks, both to this model and to others.

Ned's photos of that CP Vista-dome observation car got me thinking about how to do it, and I've met with some success. This "dining car" is actually a boat-tail observation, and the dome is an optional add-on (it's technically Truck3, a separate 3DP file, such that you can add it to other car bodies as well if you want to make a regular coach-dome).

No doubt, Ned will take this and give it a Canadian skin or two sometime soon (once I give him the files!).
nedfumpkin

Re: Rolling Stock skinning ideas Unread post

The car looks really realy nice. It will be a great addition to the game, and yes, I will be skinning it for the CP Rail since they still use them. :)
pure al

Re: Rolling Stock skinning ideas Unread post

Great work guys, haven't visited this thread for years!

WPandP is that a new 3D model?
WPandP

Re: Rolling Stock skinning ideas Unread post

PureAl-

It is a new model, though based on the existing passenger car body. What I did was to write down the X,Y,Z values of the points that define the car end (i.e. the profile), then took those into my CAD software at work to build up a wireframe model of the boat-tail end. I worked from various plans and photos, having to adapt to the inaccuracies of the RRT3 model (the real roof should be much taller and less flat). Ultimately, this wireframe let me know what the new vertices would need to be, and I wrote down all those X,Y,Z values.

Armed with such data, I went into the Body.3DP file in my hex editor, and began adding points. Then, I used a similar procedure to create the faces and map the skin file. For lack of extra room in the skin file itself, the group of 3 windows on each side of the rear door is really just a repeat of a single window, on the 3 panels that comprise the curve.

The dome was done similarly, first by wireframe in CAD then transcribing all the vertices and then hex-editing them in. However, for the dome I created a Truck3.3DP to keep it separate from the car body; just by removing this file, one can have a non-dome version. It is skinned as just a single window repeated many times over, and the roof on top is just skinned with the regular roof that is right under it. The way the game engine works, you can add additional components to a car model just by naming them Truck3, Truck 4, etc. The center point that you declare right at the start of the 3DP file determines how that truck rotates on the track; as long as you set this to 0,0,0 (same as the Body.3DP) then it won't move independently of the body.

Yes, this is a very cumbersome method of working! Consequently, I won't be churning out all manner of new models; I want to get back to my freight cars. But it shows the possibilities, as do my Class A and SD40 mods, which did the 3DP modding but without the benefit of CAD modeling to inform them; they were just done by eye, based on intuitive sense of proportion. The one project that still haunts me, though, is to convert the GP-7 model into an ALCO notch-nosed RS-11 or RSD-15 (or both); just a little bit of modeling each nose is all it seems it would take, though I could see it becoming a big project if one starts paying attention to radiator positions and fuel tanks, etc.
WPandP

Re: Rolling Stock skinning ideas Unread post

I should also mention that it took a fair amount of time to work out the normal vectors for each point. In fact, the rough modeling was done fairly quickly; the normals took the longest time. What I ended up doing was just interpolating, so while the values I used might not be exactly correct, they do take care of the issue I was facing when I had incorrect normals.

That issue, to be specific, is that the new faces didn't match the existing faces, being either darker or lighter in appearance. The normal vector tells the computer which way is "out" from the face, sort of like if you took a golf tee and set the cup end up against the face, with the point facing away. For a fully flat surface, this vector stays the same for all the points that define its corners. For a rounded surface, though, the computer achieves greater apparent smoothness by using slightly different vectors at each corner; it then shades the flat surface as if it had a bit of curve to it.

So, on the right side (where X values are positive), the normal vector is basically 1,0,0. Actually, in this case I think the Z value was non-zero, because I was matching the car body's sides which have a positive Z, but for the sake of discussion let's just consider Z=0, which means in other words that the golf tee is level and pointing due right. On the left side (where X values are negative), the normal is -1,0,0. I just interpolated between these, as the faces wrap around; my particular boat-tail has 7 edges between the 8 faces that wrap around, so I just had to calculate vectors for these.

At the very rear, or at edge 4 of the 7, the vector should be pointing straight back, meaning that X=0 and Y=1 (positive Y values are to the caboose end of the train). Thus, edge 4's vector is 0,1,0. Now, all I had to do was fill in the other 3 vectors for each side:

Begin: 1.00, 0.00, 0 (right side)
Edge 1: 0.75, 0.25, 0
Edge 2: 0.50, 0.50, 0
Edge 3: 0.25, 0.75, 0
Edge 4: 0.00, 1.00, 0 (rear)
Edge 1: -0.25, 0.75, 0
Edge 2: -0.50, 0.50, 0
Edge 3: -0.75, 0.25, 0
End: -1.00, 0.00, 0 (left side)

If you're smart, you'll recognize that those values would only be true for a perfectly circular body, whereas this body is an ellipse which means that it curves more sharply at the rear than at the sides. However, I don't think you can tell in the game that it isn't "right".

I had to do the same thing for the roof, which curves in all directions, which meant interpolating all three values, not just X and Y. But again, my starting point was just to see what the vectors were for the points that form the end of the roof (where my boat-tail was attaching), then think through what the vector should be right at the rear, and just interpolate between these values.
pure al

Re: Rolling Stock skinning ideas Unread post

I must admit that does sound like a lot of work, although most of the modding we do to RT3 is extremely complex compared to other games. It does make me think about possibly updating patch 1.06 with new building models to replace the temporary warehouses we put in, but that would probably take a few years and wouldn't give a good enough return on investment. The only reason we didn't create more custom buildings (like the quarry) is because I didn't have enough time, so it's partly my fault people are complaining about warehouses being everywhere. Maybe I'll do a better job for RT4 whenever that's released :)

I looked at the Blender 3DS exporter and tried to convert it into a 3DP exporter, both formats are similar, but I didn't get very far. It's possible this could still be done by someone with enough phyton scripting experience, although I don't think anyone with those skills visits these forums.

What you've managed to do is very impressive - I must take a look at the other links you guys have posted here over the past year !*th_up*!
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bombardiere
Hobo
Posts: 28
Joined: Tue Nov 14, 2006 9:07 am
Location: Turku, Finland

Re: Rolling Stock skinning ideas Unread post

Hello all

It seems that old posts and old posters do not die easily. I am still here or there… Still busy with all kind of things.

But hey, wow! I am trying to digest things you have discovered. I understand the principle, but putting it into practice is a different matter. And I really need to start going through all the thread and try to figure out what you all are up to. Trainmaster uuufffff only if I had more time.

However, after a long break I again installed RRT3 in my computer and played couple scenarios. I have enjoyed much, so lets see if inspiration rises once again.
Grandma Ruth

Re: Rolling Stock skinning ideas Unread post

Hey, bombardiere - nice to hear from you again! :-)
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