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Big Dog - Birth of a Steam Locomotive

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    DAY 5 - Part 2

    When building a model - I'm always searching to find as much information on the prototype as I can... Any photos will help the modeling process and any specs will certainly aid in the creation of an ENG file when we get to it...

    This is one interesting quote I found on the L&HR 90 Series Consolidations - "these were very large 2-8-0s with tractive effort nearly as great as the USRA's heavy Santa Fe's. Fitted with the big Wootten firebox under a conventional cab, these Consolidations saw steam out on the L&HR and retired in 1950". Not too shabby for a little 2-8-0 - eh ??? In fact - when comparing figures with the L&HR Class 10 Mountain I built - the Consolidation has a greater tractive effort... I guess the Mountains may have been the sexy princesses of the L&HR - but - the Consolidations got the job done...

    Full Specs:

    So - back to the model...

    Let's start with the major handrails that run the length of the boiler...

    HANDRAIL BUILDER - Select an appropriate face and input desired parameters

    We now have a handrail - just move to appropriate position

    The handrail going from the end of our new handrail to the pilot deck is fairly complex... We are going to use the PIPE ENGINEER plug-in for this part... The run is illustrated on our drawing - so it's easiest to align when you are looking at both the front and the side view at the same time... We need to drop a cube and extrude/move/align the shape so one edge follows the run of the handrail... We don't care what the resulting shape looks like as long as we have a contiguous path along the edges of the resulting shape... Keep in mind that every change in direction will add more polys to your handrail - so - only change enough to get the job done...

    Create a shape to follow the handrail path

    PIPE ENGINEER - Select your EDGES - input data - and create your new handrail

    You could duplicate the procedure for the other side... I normally just copy my parts - then flip them via the "Flip Object" tool in 3DC...

    Copy and Flip for other side - than add the simple cross member in front

    The handrails are done - so let's add some more details to the boiler... These parts are all added via skills we've already covered - so it should go pretty quick...

    Protection Valves - I'm not sure if there are two or three - as they are enclosed in a shroud - I put three

    Add some Steam and Sand Domes

    Template for some Sand Lines - needs to be slightly larger than boiler due to angles

    Sand Lines installed

    Well another nights work complete... Not too bad for about five evenings work into the project...

    To be continued...
    Last edited by scottb613; 02-09-2011, 03:18 PM.
    <a href= title=thumb_80663.png >thumb_80663.png</a>​ My Blender Models



      It's time to flesh out some of the details on locomotive... There is nothing really new here - just using the basic object manipulation functions of 3DC to create various parts and accessories on the model... It's always a pretty good idea to add any complex parts you make to the component library - as you go along - that way - if you make changes - you can always revert back to the original if you don't like them... Along these same lines - it's smart to save many different versions as your model progresses... If you get further along and have an issue - at least you can backtrack to a good version without losing all your work... I have about 120 different saved copies on the Mountain and I'm up to twenty on this one...

      Simple cubes make the running boards

      Add some ladders from the pilot deck to the running boards

      Build out the Worthington feed water system

      Add some compressors for the air brakes - still needs work

      A generator for electrical power

      Starting to get close to the running gear - power reverser

      And just because everything looks better in POV-Ray

      Yeah - 3DC has an interface built so you can view your models in POV-Ray - right from within the application... In addition - you can export to POV-Ray or most other 3D formats for more detailed work... We've knocked out some of the easier stuff because it goes quicker... The running gear is not hard but takes some effort because we need to animate all the parts... The cow catcher on the front takes a little time - and - I need to work the area under the cab which can be tough because of the lack of good pictures...

      To be continued...
      Last edited by scottb613; 01-31-2011, 07:26 PM.
      <a href= title=thumb_80663.png >thumb_80663.png</a>​ My Blender Models



        Well - this is a steam engine so at some point we are going to have to deal with all those moving parts that make this thing move...

        Before we can get into animating parts - we need to talk a little bit about the model hierarchy and groupings... Groups in 3DC are defined with your typical "Parent"/"Child" relationship... See hierarchy below... When you first run the "TRAINWORKS Engineer" plug-in to generate the wheel sets - it creates the basic model hierarchy for you... In order for the 3DC MSTS exporter to work - your model must be contained - in its entirety - within the highest level group called "Main"... Whatever is not in "Main" - will not be exported... The plug-in creates groups for each wheel/axle pair - prefaced with the name "Wheels" followed by a number assignment... "Wheels4" is special in this case - because it contains the groups for the connecting rods that link all the drivers together - groups “Rod01” and “Rod02”... "Bogie1" is the group for the pilot truck and contains a CHILD group for the wheels - "Wheels11"... "Solebar" and "Underframe" are just two parts contained in the group "Main"... I use the "Solebar" as my core reference for centering and aligning everything on the locomotive... It's actually a good idea to "LOCK" the "Solebar" in place so you don't accidentally move it...

        Group Functions
        - A logical grouping of parts...

        -All objects within a group move at the same time when modeling...

        -Every part with a different animation should be contained in its own group... So when we start modeling the running gear - each rod will be contained in its own unique group...

        -Once you have a group animation defined - adding parts to that group will impart the same motion on the new part...

        -You can call your rod groups whatever you want – the exporter is smart enough to identify the part by its motion – and – formats it correctly for MSTS on the export...

        -Every group/object has a pivot point... The pivot point is where all three axis converge and is the point at which the object will rotate in space... An object added to a group will assume the pivot point of the group... For much of the model - this is not very important - for the parts that are animated this is extremely important...

        Locomotive Hierarchy


        ++++ Wheels1

        ++++ Wheels2

        ++++ Wheels3

        ++++ Wheels4

        ++++++++++ Rod01

        ++++++++++ Rod02

        ++++ Bogie1

        ++++++++++ Wheels11



        Sometimes it's easier to build a complex shape by starting out with two or more simpler shapes... Again - be conscious of polys because complex parts can eat them up pretty fast... While 3DC has always had the ability to weld - welding two or more objects together is a new feature to version 8... Prior to 8 we had to "merge" the objects before welding...

        There are a few different weld operations available to choose from... The operation I use most often is "Weld To"... This moves all subsequent points - to the exact point in space occupied by the point you chose first... I needed a fairly complex part to hold the rails that the crosshead arm travels back and forth on with the motion of the piston...

        Start with two simple shapes created by using basic "extrude" and "shift" operations

        Position shapes in respective locations - align using "Butt Shapes"

        Select some points - first one selected is final location of weld

        "Weld To"

        Select points - "Weld To"

        Select points - "Weld To"

        Select points - "Weld To"

        Completed shape ready for use

        Back to the Consolidation – as illustrated below – we have some more differences we need to contend with... The valve gear on our plans doesn't match the valve gear on our prototype... While both are Walschaerts valve gear – some of the components are different shapes and sizes... Once we start putting it all together – we may have to make some modifications - on the fly - to get it right... Even though the scale drawing is not an exact match – it will still help getting the scale and relative positions down...

        I've highlighted in color all the rods we need to animate... Looks pretty complicated – right ??? It will take some work but 3DC has tools to make the job easier...

        It's also nice to have reference material so here is some stuff from Wikipedia...

        Walschaert Valve Gear

        1. Eccentric Crank (Return Crank)
        2. Eccentric Rod
        3. Reach Rod
        4. Lifting Link
        5. Lifting Arm
        6. Reverse Arm & Shaft
        7. Link (Expansion Link)
        8. Radius Bar/Rod
        9. Crosshead Arm (Drop Link)
        10. Valve Stem Guide
        11. Union Link (Anchor Link)
        12. Combination Lever
        13. Valve Stem
        14. Valve Spindle

        To be continued...
        Last edited by scottb613; 02-04-2011, 07:15 AM.
        <a href= title=thumb_80663.png >thumb_80663.png</a>​ My Blender Models


          DAY 7 - Part 2

          We need to get some of the parts we will be animating staged and ready for use...

          Let's start with the driving rod - basic cube - shaped and extruded
          *** Note the length - we'll need it later ***

          Let's add some rails for the crosshead to travel on

          Add the support we made in the last post

          This whole assembly will be referred to as the "Piston Object" for our next phase of animation

          Finally - I used the "TRAINWORKS Engineer" to build out a quick second model for the tender... The tender on my initial drawing doesn't match the prototype for the L&HR... I found an appropriate match on plans for another locomotive... I built the tender - now - as a place holder and to insure I had a close match for the prototype... It looks good to me... It will also help when we get to working on the rear end of the locomotive... This took about 20 minutes to setup and complete - including the scale backdrop images for modeling... It can go pretty quick once you get the hang of it...

          To be continued...
          Last edited by scottb613; 02-09-2011, 06:01 PM.
          <a href= title=thumb_80663.png >thumb_80663.png</a>​ My Blender Models


            DAY 8 – WE HAVE AN APP FOR THAT

            Probably the most dreaded question in modeling a steam locomotive for the first time is – how in the world am I going to get all those rods moving in a proper manner ??? Other than the wheels - I count ten different moving parts on our scale drawing – per side – that all need to move with their own respective motion… Pretty intimidating for the uninitiated – right ??? For those of you unfamiliar with animation sequences in MSTS – it’s nothing more than a series of stop motion positions of the object being animated… It’s very similar to the very first animated cartoons ever made… The subject needs to be posed in each one of the required positions (frames) so MSTS is aware of how that object is expected to move… As I understand it - MSTS will interpolate the intermediate positions between frames for use in the Sim… What’s this all mean to the modeler ??? We have to set our locomotive valve gear in each one of these “frame” positions and save it to the model… Luckily – we don’t have to do it all at one time…

            It's nice to know what we are trying to accomplish - Wikipedia provides another fine example...

            Valve Gear Motion

            As mentioned previously – the “TRAINWORS ENGINEER” plug-in that create our wheel set – also created our connecting rod and bearings… All these parts are already fully animated with the 90 degree offset required by a steam locomotive…

            Since our last modeling session – we needed to create a few more items to get the primary parts of the Valve Gear created and ready for use… So let’s whip out these parts so we can get down to the first steps in animating our locomotive… We can use the reference drawing in the last post for naming our parts…

            Eccentric Crank – Eccentric Rod – Mount for Expansion Link – Expansion Link

            So we now have enough parts to start the animation process…

            Here is where 3DC TRAINWORKS provides another amazing plug-in called “ROD ANIMATOR”… ROD ANIMATOR is capable of animating the – wheels – bearings – connecting rods – piston object – eccentric crank – and – the eccentric rod… You have no idea as to how much time this will save you… It works extremely well and produces some of the smoothest animation sequences I have ever seen in MSTS… This is another fine example of Paul Gausden’s work…

            Rod Animator Parameters
            +Select Rod Group
            +Animate Rod as Wheel Link
            +Select Piston Group
            +No Piston Object
            +Piston Angle
            +Rod Length
            +Key Frames

            The parts Rod Animator will animate - bright colors

            ROD ANIMATOR has a few prerequisites in order to allow it to function properly…

            Model Heirarchy - Each one of the Valve Gear parts needs to be placed in its proper location in the model hierarchy before we can run the plug-in… The actual parts must be contained in separate groups and the groups may contain multiple parts… For this next operation – we need to work with the following groups… The names are not important – I just find it easier to use their correct names…

            1) Eccentric Crank (Child of Wheels3)
            2) Eccentric Rod (Child of Wheels3)
            3) Driver Rod (Child of Wheels3)
            4) Piston Object (Child of Main)


            ++++ Wheels1

            ++++ Wheels2

            ++++ Wheels3 (Drive Rod Link)

            ++++++++++ Eccentric Crank

            ++++++++++ Driver Rod

            ++++++++++ Eccentric Rod

            ++++ Wheels4 (Connecting Rod Link)

            ++++++++++ Rod01

            ++++++++++ Rod02

            ++++ Bogie1

            ++++++++++ Wheels11

            ++++ Piston Object



            Pivot Point - The other key ingredient to make this plugin work is the object’s “pivot Point” (place where the X,Y,Z axis meet – rotation point) has to be in the correct location… This can be moved in one of several ways… The way I do it most of the time is with the “Shift Center” plug-in… Now keep in mind the rules of groups we have already discussed – any object added to a group will assume the “pivot point” of the group… So when creating a complex object such as the "Piston Object" illustrated below - your very first part should be the cylinder that is the connection point to the "Driver Rod" - add all other required parts to this initial group... That way - any other objects you add will not change the groups correct orientation...

            Piston Object Pivot Point - center of mass of cylinder - faces removed to show axis

            Driver Rod Pivot Point - aft most face of rod - faces removed to show axis

            Driver Rod and Piston Object Pivot Point

            Eccentric Rod Pivot Point - no piston object

            Once the parts are setup as described above - we are now ready to use the plug-in to animate the parts... When we originally created the wheel set the animation was set to 8 Frames - meaning it will take 8 individual snapshots to complete one revolution of the wheel... While some people claim there is no benefit - I prefer to use 16 frames myself... MSTS requires all objects on a model be animated with the same number of frames... Normally - changing all this would take a substantial amount of time - Rod Animator - allows us to accomplish this in a minute or two... Lets work through this as we run "Rod Animator" on each one of the drivers... Rod Animator "rod" motion is always dependent on a wheel set...

            When you run Rod Animator on the wheel group containing the rods - it will link the "Driver Rod" (circular motion around the wheel) to the "Piston Object" (back and forth motion of a piston)... The pivot point of the Driver Rod will permanently attach to the respective wheel... The Piston Object's pivot point will join to the forward end of the Driver Rod - by sliding on the Z axis - based on your input for the Driver Rod length... It will keep all these points automatically attached through every frame of the wheel rotation...

            Wheels 4 - has Connecting Rods "Rod01" in it - so we need to animate as a "Wheel Link" - No Piston

            Wheels 2 - has no rods - so just run plug-in - with no changes - to animate to 16 frames

            Wheels 1 - has no rods - so just run plug-in - with no changes - to animate to 16 frames

            That's it - we now have all the wheels - except "Wheels 3" with all our rods - fully animated to 16 frames...

            To be continued...
            Last edited by scottb613; 02-10-2011, 07:37 AM.
            <a href= title=thumb_80663.png >thumb_80663.png</a>​ My Blender Models


              DAY 8 – Part 2

              The last step is to run the Rod Animator on the "Wheels3" group - as this is the group that will control the motion of our - Driver Rod - Piston Object - and - Eccentric Rod... In order to do this - we need to run the plug-in twice on "Wheels3"... The first run will animate the Driver Rod and Piston Object - the second run will animate the Eccentric Rod... For both the Driver Rod and Eccentric Rod - the length is critical - so make sure you have a good measurement...

              Select Wheels3 - Select Driver Rod Group - Select Piston Object Group - Input Length

              Run Rod Animator - the Driver Rod and Piston Object should connect as illustrated

              Select Wheels3 - Select Eccentric Rod Group - NO Piston Object - Needs 3 Degree Offset - Input Length

              Run Rod Animator - the Eccentric Rod should connect to the Expansion Link as illustrated

              If it's all done right - it should look something like this

              That's it - we now have all those parts fully animated and ready for export... Once the parts are setup - you can animate a full side of the locomotive in less than 5 minutes... We still have some more rods to animate which - unfortunately - we will have to do by hand... This plug-in saved many hours of work to establish the core motion of our rods... It will be much much easier animating the remaining rods since the core motion is so well defined...

              Of course we have to repeat these steps for the other side of the locomotive as well...

              And you thought this was going to be hard - LOL...
              ; )

              To be continued...
              Last edited by scottb613; 02-10-2011, 09:26 AM.
              <a href= title=thumb_80663.png >thumb_80663.png</a>​ My Blender Models


                Great job on the Tutorial so far Scott, your time is appreciated, Thank you.



                  Hi Steven,

                  Glad someone likes it - I think I've actually spent more time on the tutorial than I do modeling...

                  Thanks for looking...
                  <a href= title=thumb_80663.png >thumb_80663.png</a>​ My Blender Models


                    Thanks Scott! Your tutorial is very much appriciated. It looks almost easy. I'll give it a try someday. Thanks again!
                    with kind regards,
                    "It never hurts to help!" - Eek! the Cat


                      Looks great, I just have one question. When are the Wheel Weights going to be added?


                        Hey Guys,

                        Thanks again... I guess that was my intent - to hopefully inspire some new folks enough to dive in and give it a try... I remember being pretty intimidated on my first model - a Prairie - that I uploaded years ago... Luckily - so many people were kind enough to take the time to answer hundreds of questions for me... I had a great deal of help... Figured the least I could do was pass some of their knowledge along... Even with all the shortcuts - it takes a great deal of time - but - it's also pretty rewarding seeing a real piece of history leap off the 2D pages of some old magazine... These same skills can be used to build anything in 3DC... If you guys recall the old NALW AMTRAK FP40's that we used for years - a guy named BuzzBenz used 3DC to make them... Oh - and 3DC also exports to Trainz and Railworks - for those so inclined...

                        As far as the wheel weights go - I'm looking for good performance out of the model... The wheels you see now are just high poly place holders until I get around to building the alpha wheels... Wheel weights are one of the sacrifices I'm willing to make to the poly gods... The production wheels I use are really alpha channel wheels to begin with – so I do the counterweights as part of the alpha channel... If you're not familiar with Paint Shop Pro – PSP has a bunch of tools to make 2D textures look very 3D... If you check out the Boxpok drivers I made for Mountain on the first page – I think they look pretty decent... I spent like a week on the drivers alone... Even though they are alpha on the outer face and inner face – they have a true 3D - inner rim – outer rim – hub – flange - and - spokes...
                        Last edited by scottb613; 02-09-2011, 07:47 PM.
                        <a href= title=thumb_80663.png >thumb_80663.png</a>​ My Blender Models


                          I see... I don't really work with PSP... (On money to buy it) But yeah... She is looking great.


                            DAY 9 – IT’s NOT COW TIPPING

                            Ready for another modeling session ??? This session will attempt to help you out with modeling the ubiquitous cow catcher… The term "cow catcher" always seems to invoke a friendly connotation - like it gently picks up the cow and puts it aside - LOL - I don't think it was quite so friendly in real life... My first time through I probably spent more time building this part than any other part on the locomotive… I didn’t have much experience with 3D modeling and I wasn’t very familiar with the available tools which would have made my life much easier… It took forever - like a week - really...

                            The cow catcher on the Mountain was pretty difficult as well – but - it had a complex shape - with many angles - and - had alpha channel holes punched through it… The more common variety I am building now – can be done pretty quickly if you have a basic understanding on how to do it…

                            My first time through – I built the entire “Cow Catcher” as a single unit - which was a mistake... I was trying to get all the stringers (vertical part between the top and bottom of the frame) all lined up with matching angles… There is an easier way… Many times when modeling - it may be better to simply build half of a symmetrical part - then duplicate and flip the shape to make it match up and finish the other side… It’s much faster than building the entire frame – and – yields better results as both halves will be perfectly symmetrical…

                            Zoom in to our work area and drop a cube

                            Size the lower frame to match the plans

                            Drop and size the upper frame to match the plans

                            Now one of the most important capabilities of 3D modeling software - is the ability to LOCK the axis... This allows you to control the movement of your - shape - face - point - or - edge in a very controlled manner... This is what makes building the cow catcher simple... We are no longer care what the angle is on the shape - we are simply sliding the face to the appropriate position and the angles determine themselves...

                            Drop - Size - and - Position your first vertical stringer

                            Grab the Top Face - the multiple views really help here too

                            Now with the X and Y axis locked - simply slide it back into the proper position along the Z

                            While similar - the cow catcher in the plans doesn't match up with the L&HR prototype - so once again the model is being modified to match photographs of the real locomotive...

                            Repeat the same process for all the vertical stringers

                            Select and copy the entire half of the shape

                            Flip shape and Align in proper position to complete the Cow Catcher

                            We now have a decent cow catcher completed in less than 30 minutes... Not too bad - right ???

                            To be continued...
                            Last edited by scottb613; 02-15-2011, 06:34 PM.
                            <a href= title=thumb_80663.png >thumb_80663.png</a>​ My Blender Models


                              Day 9 - Part 2

                              Since the cow catcher went so quickly - lets get some more work done...

                              Make the coupler visible and add some steps

                              Going back to the PIPE ENGINEER to build out the pin puller assembly

                              This concludes most of the work on the pilot deck - as it has about as much detail as I can afford while still keeping good performance in mind... Everything else will be added through textures... I'll probably still add an air hose line at some point...

                              Let's jump back to our "rods" for a few minutes... In previous posts we showed how to use the ROD ANIMATOR plug-in to automate the animation of the major components of our Walschaerts valve gear... While the core components are done - we still need at add a few shapes to get setup for animating the remaining rods by hand... It takes a little work getting these rods positioned properly - as you have three fixed locations that will determine the placement of all the rods on the X axis... They are the outside face of the wheel - the center of the piston cylinder - and - the center of the valve cylinder... The easiest way to work on this is just build all the rods and place them in their proper Y and Z axis location - then start juggling them around for their proper placement on the X axis...

                              Another note I should have mentioned earlier - always save a good copy of your model - prior to performing any animation work... That way - if things get messed up you can always revert to a known good start position...

                              For my work here - I am positioning all the rods on a model that has never been animated before... This allows me to use the scale drawings to size and position the rods correctly...

                              We'll get into "hand animating" these rods another night...

                              So nothing fancy - added the rods with vivid colors - then worked out proper X axis position

                              I'm not a stickler for building very complex frames... I don't want to waste too many polys on them - as they are not very apparent in MSTS... I did modify the frame so it has the proper silhouette and added some of the more obvious details using simple shapes... To further obscure the view - I normally add an alpha'd shadow box under the boiler to make all the frame components appear to be in shadow... It usually works out quite well...

                              Size and Shape the existing frame components to match prototype

                              Add some leaf springs

                              Finally - I tweaked the firebox shape for a better fit to the boiler - AND - that's about enough work for another night...

                              OK OK - I Like POV-ray

                              To be continued - same bat time - same bat channel...
                              Last edited by scottb613; 02-15-2011, 06:44 PM.
                              <a href= title=thumb_80663.png >thumb_80663.png</a>​ My Blender Models


                                Man, almost makes me want to try again at modeling! Great job, even without the paint, it looks real! And I can't belive it only took you 30 minutes to create an entire cow catcher. Your the master at this business.