Steam Locomotive, LiDAR Landscape

I’ve been working on getting my locomotive models into broader settings. In this work in progress, I’ve started with raw LiDAR data provided by the UK government. This provides a very accurate base model which I then populated with various tree, grass and crop assets - some purchased, and some scratch built. The overall goal of this project is to be able to place any LNER A1/A3 locomotive in any setting in the UK. This is my first attempt to bring all of this together.

This image also shows some experiments with steam, clouds and procedural ballast. The steam is build using a hand-crafted envelope with several layers of displacement. The clouds are rendered using simple volumetrics at full scale and the ballast is fully procedural.

There are plenty of things that I need to fix in the image, but I’d love to hear any feedback.

Here is a clay render of the model.

Finally, an updated thumbnail.

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Maybe the smoke has too much water (white) ?

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If you hadn’t posted the second image i would said: No photos please… liked.

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Looks like an old post card, brilliant!

I think that is something of an accidental aesthetic, but I see exactly what you mean. I always pull back the saturation from the raw render - might be a good idea to put up some variations that explore different parts of the scale.

I’ve just started to explore LiDAR for landscapes as well, from the USGS. Nothing worth posting yet :). Do you have a link to the UK data? I’d like to see how they compare.

I’m curious what tools you’re using to process the point clouds for use in Blender. I’m leaning toward PDAL, or something similar, which can be scripted to process many tiles rather than doing each one by hand. Have you tried a few tools, and if so, which do you prefer?

Hi Kris,

Data for England and Wales can be found here: https://environment.data.gov.uk/DefraDataDownload/?Mode=survey they have already converted to basic height data and you can download either the surface (including vegetation and buildings) or the terrain (automated processes have removed manmade artifacts and vegetation).

Scottish data is available here: https://remotesensingdata.gov.scot/data#/map

The English data is available in ESRII ascii format but the Scottish data is only available as geotif. You can use the Blender GIS addon to import the ascii data (it has a function to import tif but it has never worked for me). If you need to load the Scottish data you will need to convert from the tif format.

Let me know how you get on.

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The steam is really challenging - I think it is improving but not yet fully figured out the right approach. I’ve never been happy with simulations for this and I think the handcrafting approach I currently use will eventually get me there.

The reflections on rail cars sides are excellent. But the ilumination seems too much for the sun position which is relatively low by the shadow, but i could be wrong and the sun can get this intense in Northern hemisphere winter (it is closer to Earth at that time)
There is no smoke shadow on field, i think it would improve the composition , and in second smoke bottom illuminated bulge seems it should not get the sun there.

Hi Bullit - I think that’s a good call. I went back and checked the lighting - with the position of the sun as it currently is, and the height of the steam / smoke, the shadow is actually off camera. I’ll play around with different lighting and see what happens.

Ontogenic note the smoke shadow(or part of it) can’t be off the camera in this image since the locomotive shadow is fully represented in the image so the smoke getting out from it should appear too.

Hi Bullit - it’s slightly confusing - the shadow of the locomotive actually falls into the tall barley, so while it looks like the top of the smoke stack is visible, it actually isn’t. I verified this by rendering the image without the barley. That being said, I think is it confusing to the observer, so lighting this so that it is clear (i.e. that the shadow of the steam is present) will be a big win. I hope to get that posted today.

Ok - I think changing things around so that the steam shadow hits the field is a big improvement. More adjustments are needed to help the colours work, but overall a good direction - what do you think?

I’m also noticing the amount of reflection on the carriages. I suspect that is coming from the way I’ve split the scene up (2 files with compositing). More experimentation is needed.

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Quite by accident, the most recent image composes a background with a different lighting set up than the foreground. However, this gives a nice variation - as if the clouds are partially occluding the light in the foreground, but letting the sun light up more of the background.

A semi overcast day now but the sun got higher so the time of the day changed. Smoke is now represented in shadow.
It seems there is a cut in grass shadow after the 3rd or 4th rail car. After that it is no more except in gravel. Don’t see in the scene justification for that.

What makes some bottom parts of smoke being more illuminated? reflection from the rail cars roof tops?
Clipboard 2

Last update for today - this has a slightly brighter sun positioned to place the shadows in better locations as well as a recomputed steam with the correct lighting. This version is also slightly less desaturated. I’m finding the way the steam shadow interacts with the barley field to be very satisfying. It probably needs a longer render to do it full justice.

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I featured you on BlenderNation, have a great weekend!

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Simply stunning. I shall be very happy if I get to this stage with my own locos etc. Can you give any hints regarding the steam please. I am still just fudging it with photoshop.

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Hi Robert - appreciate the comment.

Regarding steam - I’m still very much trying to figure this out myself. My current process is to create an envelope object and then work on the volume shader for additional detail. To create the envelope, I first use metaballs to get the overall shape. At this stage I look at a lot of references - the steam from these locomotives captures the narrative of the mechanical action, so it is important to respect that in the shape. I then remesh and apply a subdivision and I then apply both. Following that, I work with either 2 or 3 layers of displacements. I find using voronoi textures (which you have to invert) can create the bubbly details. I also use the voronoi in the volume shader to provide additional detail. It can also be useful to add in some noise with distortion as this can provide some amount of swirling.

I would like to do a full write up, but don’t think I’ve really nailed it yet. Another thing that I’ve experimented with (but not in this image) is reducing the density as a function of distance from the origin.

Finally, I would say start off small - the first thing that I did that was half decent was just the steam blowing from the cylinder cocks.

I took a quick look at your pictures. It’s great to meet a fellow 3d model railway enthusiast (we also happen to come from the same great nation).

Hi,
Thanks for your advice regarding smoke and steam. I will use your advice to try and improve that aspect of my modelling for the next new project (Caledonian Railway).
Since moving to Scotland my interests have turned away from the GWR to the Scottish railway scene around 1900. I feel I need to start something completely new…

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