R Reynolds

Actually, I built that as a favor to Greg. And I'd like to think it can hold it's own against Stian's finely crafted model. In my opinion, the weakest link in the attached render (from April 2000) is the lighting. I may have to try a new one with AO.

As the others have said, you need a bigger reference picture. Fortunately you've chosen to model a Pennsylvania Railroad GG1, one of the most obsessed over electric locomotives. So there's LOTS of pictures of it in 3/4 views but as usual with big vehicles, very few orthogonal views showing the whole thing. I can offer the attached four images whose lengths are all larger than the one you have. I think you'll be happy with GG1_b.gif which is a pretty large line drawing. I also threw in a picture of the chassis and trucks that I stumbled across during the search.

Is this the look you're after? http://www.hash.com/forums/index.php?showt...1&hl=bottle

It appears from your example scene that you're trying to simulate sunlight which is basically a single, extremely distant area light source. I have been able to satisfy my needs with a 208 ft. diameter klieg with the properties shown in the attachment, located almost 3.5 miles from the models. I also use ambiance occlusion to fill in the shadows with sky light but that may not be the look you're after.

Thanks to everyone for their encouraging words. robcat asked: Your question sent me on a web search that yielded "a device for transmitting motion for some specific purpose". I always thought of a gear as a multi-armed lever or a lever as a single toothed gear, both transmit force about a rotating axis. John asked: I used to; went so far as to build a 1/48 scale set-up in the backyard so I could use natural sunlight to photograph them with a second hand 16mm movie camera. But 1/4" to the foot scale still wasn't really large enough to make the movies convincing. Then I discovered A:M and realized I could get the camera as close as I wanted and still maintain focus. The backyard set was soon dismantled. jason asked: Usually I'm OK with sharing my models but this one's going to be my pride and joy. As an alternative I can offer a hi-res view of all parts in wireframe. If there's any specific section you'd like to see more closely, just ask.

As the title says, this is the linkage used by steam locomotives to allow them to move forward or in reverse. The idea of splining the convoluted shapes and transitions intimidated me so much that I kept putting off starting them for months. But I finally bit the bullet and I think they can stand up to an arm's length inspection. The quasi rectangular frame (which is about 6 ft. long) has a close approximation of the final cast iron texture for all the parts but the Playdough colours on the other parts are just to ease inspection.

These are the quirks you have to get used to when attempting accurate mechanical modeling with A:M's splines. I have this vague memory from the last century that Hash splines did not originally act this way but due to complaints from character modelers concerning their difficulties of modeling faces without creasing that the spline algorithm was changed to include averaging over local cp's. I know all too well the temptation to concentrate on one local feature (a nicely hemmed sheet metal edge for instance) making it "perfect" and then moving on thinking it's finished, forever. But you really don't want to tweak bias until you have a significant chunk of the object built. And you'll just have to get used to re-tweaking splines after you do a C/F/A. I've noticed that typically the sign of some alpha's get flipped after that operation in an unpredictable way. After the C/F/A, put your model in wire frame and look through it for splines that don't match. Click on the badly aimed spline and change the sign of its alpha; + to - or - to +. This works most of the time but as I say it's unpredictable. Once you're mentally prepared for this added task; it's easier to swallow. As for nice shiny paint, I'd suggest a specular colour closer to white, low specular size (5?), high specular intensity (90?) and higher reflectivity (40?). Make sure you use a number of lights and surround your model with a background so there's something to reflect.

I have a model file of various connector hardware that I use regularly. I try to keep patch count low so you can add a lot of them to a model. The hex head bolts and nuts come in low and hi patch counts depending upon how much scrutiny they'll come under. If this looks useful, I can upload it to this thread.

Thanks Eric. It does help because it confirms one my strongly held beliefs; if you start with the assumption that you're going to add as many splines as needed to fillet every corner you have nothing to fear from five pointers.

First rate craftsmanship Eric! May I please see a close-up wireframe of one of the wheel spokes showing the transitions into the hub and rim? I'm resplining my locomotive wheels and I'd appreciate seeing your solution.

Nothing magical. A bump map comes from applying a simple gradient material that sets the color of the top of the model to (255, 255, 255), the bottom to (0, 0, 0) with a smooth transition between. Make sure you set the model's specular color to (0, 0, 0) as well. A render of a top view of such a model yields a decal where height is proportional to gray value (see attached image). As a side note, in the case of the rosette model which is a raised detail, if you applied a gradient that set the top of the model to (255, 255, 255) and the bottom of the model to (128, 128, 128) you would now have a map suitable for a displacement decal (if you can afford the render hit). The normal map is a simple application of aaver's MakeNormalMap material. found here. The only limitation being that you should test how the map renders to make sure it's default settings provide the expected results. It may be due to whatever interpolation is happening in the translation from decal to apparent surface grey value but it may also be due to the fact that I modelled some of the contours too sharp. Bump, normal and displacement maps don't play well with steep slopes i.e. rapid changes in height. They prefer rolling hills as opposed to cliffs. So I slightly blurred both maps before applying them, creating the softer edges.

I use normal maps to cheat details that don't need to stand up to arms length inspection, so there's no need to carry the overhead of those patches. Bump maps are for textures that are so small with respect to the overall surface they essentially have no depth. For instance, the cast concrete, octogonal rosettes on either side of the front wall of building I'm working on (shown in the attached WIP image) are normal maps derived from a 600 patch model. They're so far away from the viewer that it's unlikely you'll notice they have no real depth. The second image shows an angled view comparison of the original rosette model next to applied bump and normal maps (both set at 100%) that were derived from the model. IMO the normal map (although not nearly as good as the model) is far more convincing than the bump map.

Here's the method I typically use to cut holes in convoluted surfaces. The steps are keyed to the attached screen grabs. 1. Cleverly lay out the splinage in your target surface with the foreknowledge of where your going to cut the hole. In this case a cylinder with enough radial and vertical cps to keep the required five point patches as small and symmetrical as possible. 2. Draw the outline cross section of the hole you want to cut using cp's that only coincide with existing splines on the target surface. 3. Move the hole's cross section cps so they all lay in the target surface. Tweak the appropriate mags and bias so its' splines also lay in the target surface. 4. Add extra cps to the splines in the target surface to match those in the cross section. Adding cp's to the circumferential spline will naturallly cause distortions that need bias correction. 5. Stitch the cross section to the cylinder. 6. Remove splines and define the five point patches. The spline ends on the broken circumferential will need bias tweaks. Are the results boolean perfect? No. You'd need to increase the spline density to further reduce the size of the five pointers to eliminate the slight distortion near the edge. However you're likely to add edge moulding that will distract the eye of the beholder.

If I must, OK here goes. Keep in mind that it's been almost three years since I did this research so I don't remember every parameter setting but I can give you the broad strokes. The first thing I discovered was that rendering a landscape of grass/hair takes a long, long time, at least on a 1.5 Mhz Athlon. So I spent a fair bit of time trying to determine the minimum number of blades required to closely suggest grass as opposed to trying to accurately simulate every blade. On a model railroad, the stars are the locomotives and rolling stock not the scenery. My first "trick" was the material I applied to the ground, grass.mat, shown in the first image. This suitably noisy "quasi-grass" has blobs of contrasting color to suggest small discrete plants and really helps fill in the gaps between individual grass blades. The second trick was to use AM materials to produce images that can be used as maps to control blade color, length and density. The final trick was to realize that the grass texture you need in the foreground can be far different than what you can use in the background. The next three images are reduced versions of the maps used in the image of the hand-car and shed. The length and color maps are made with three different materials with gradient fades between them. The leftmost parts of the maps are close to the camera's possible locations while their rightmost parts will be in the distance, well in the background of the image. As you can see, I want more granularity, in both height and color, close to the camera to suggest more detail. My most surprising discovery was how little density I needed in the background and stiil have believable grass. So the density map basically concentrates grass closer to the camera. On the tall grass I seem to recall using the grooming tool to bend various sections of blades in realistic directions. The last image is an earlier test render I stumbled across while trying to refresh my memory on this process. It's closer to the original request for a lawn like landscape and uses similar maps to those attached. The repeated picnic table is just to give a sense of scale and distance.

The grass on the background hill was my first presentable attempt. More a field than a lawn.

Thanks for all the kind comments. See the attached image. The biggest challenge here was I had no reference image for how the plate gets held in that odd location. So I had to design a kind of aerodynamic art-deco chunk of chrome with a rusty metal frame; see other attached image. All in good time. You're absolutely correct and I did consider it. But some rough calculations suggested that you'd have to have something like 36 radial cross sections to have a moving bulge as the wheel rotated that didn't "pulse" from cross-section to cross section and it would probably still be a bias tweaking nightmare to get it to look realistic in motion. I couldn't justify this type of patch overhead on just a car. The "stars" of my virtual train set are the locomotives. They'll get the majority of close-ups and fortunately their wheels don't deform (much). I'd like to finish the city street set first so there's something to fill in the reflections. As you can see in the view without a the hood, I did model it, along with the radiator. They're very low on detail, just enough to fill the space in a worm's eye view. The Chrysler designers put a LOT of sheet metal in front of the radiator giving that see-through appearance. My ISP puts a 5Mb limit on my website and I plan on putting many more images up in the coming years.

It's been about four years since I started it and I'm still tweaking the materials but it's done, finally. Three other shots, including the interior, are here: '41 Plymouth Coupe page

My experience has been that it's the signs of the bias values "automatically" flipping and hence being incorrect for the new orientation. As far back as the 90's, this has been the case. You will also notice that it happens when you tweak one half of a model and then copy, flip and attach. After attaching, sometimes the copied bias have the correct signs and the originals flip. It doesn't happen to every bias so you just have to prepare yourself to patiently inspect your wireframe and make sure all the bias values match. You can avoid it if you model with such high density patches that all bias values stay 0.0 but this would likely be even more tedious than checking for flipped bias signs. Since it's been around so long I assume it's a feature that's unlikley to change.

You may find a workable modelling solution to your problem here: Fillet Tutorial

"Good" is a matter of taste. Do you mean buildings like this?

I find it difficult to see details in surfaces that appear to be pure white. It would be more revealing to set the model's attributes to the following values: diffuse color = 128,128,128 specular color = 255, 255, 255 specular size = 50 specular intensity = 50 then re-render and re-post.

Right you are. One of the advantages to using scale models as prototypes is you can easily build up reasonably accurate rotos by cutting and pasting sections of sequential images. No kidding. Some of the views at suurland.com are almost cartoonish in their lack of detail. And ortho top views are really rare.

No, that's all pure splinage; see first image. No, but I do own a 1/25 scale styrene model that (along with images from the net) serves as my reference prototype and rotoscope source; see second image. The road beside the stadium is a standard route; I couldn't miss it as I was driving by.

It's also a function of the lighting. The newest key (second from right) has a larger specular intensity value but its position is such that the light it reflects isn't aimed at the camera. The ring's diffuse color is black and has spec. inten. = 100; spec. size = 1; reflectivity = 60. Once again it's more a question of composition. The ring is in the wrong place to reflect the back light and the surrounding environment reflected in the rings' surface is just the camera background color, grayish blue. Yeah, this is a wood material that I never expected to withstand this level of scrutiny. I went back and forth on a logo. Since I want to be able to insert these keys into the ignition of any of my vehicles I thought it best to make it generic. (I would also like to think that in the year my CG railroad set exists (1953) the concept of branding every marketable object was blissfully uncommon). So I went with a brushed aluminum by way of SymbiontAM; not perfect but an acceptable compromise that seems necessary for any texture that tries to mimic ground or brushed metal. It's all a question of personal taste. I probably hurt myself by breaking what I consider a cardinal rule of hardware modeling; I didn't fillet any of the 90 deg. corners. Edges made with a mag of 20 and tweaked gammas don't reflect light in a convincingly realistic way. The attached 360 deg. keyset spin movie makes me think it's time to stop tweaking and move on to other things. See attached images. I've decided to really detail the chassis (springs and drive train) and dashboard (cutouts for the radio and glove compartment) since I can re-use them in other vehicles. If I can get the work visa issue resolved I'll be spending a fair bit of time north of the river. Impressive but the textures on it are too bright and clean. keys_spin.mov

Talk about getting sidetracked. I was working on the dashboard for my '41 Plymouth when I had the thought that it would look more authentic with a key in the ignition. Then I realized that a single key would look a bit odd which led to more keys with different shapes on a ring and finally a fob. The keys have no teeth since I didn't want to further complicate the models and this lack of detail would unlikely be noticeable in typical shots of the car's interior. The large unassembled image was the test for the textures (all done with Enhance A:M combiners). Why is it relatively easy to make something look fresh-out-of-the-box new or rusty, dirty and decrepit but it takes many iterations to make an object look slightly used or sort of old? I still don't think I'm there yet but I'm getting close. The small assembled image is one frame out of a 360 deg. spin.