Here is a video highlighting some features of my visual Earth curve and horizon calculator, created in Unreal Engine 4.
Here is most of the information presented in the video.
Quick update on the features I’ve recently added to the simulator.
Flat/Globe buttons now indicate which mode is active.
The simulator draws the ground in blocks in front of the viewer based on the curve formula or flat depending on the mode. Draw distance controls how far to render the ground/water surface.
Block size hasn’t quite been implemented, but it will soon allow for shorter blocks of ground to be placed giving a more accurate curve.
Updated the math for placing blocks according to the curve drop formula: r-sqrt(r2-d2), instead of 8cm per KM^2. This allows for the radius of Earth to be changed.
Better camera control. The camera can now move forward and backward in the scene as well as side to side.
The camera angle can be changed on 2 axis. I set the camera angle change to .05 degrees at a time. Angle and zoom combinations can be precisely set to over dramatize the curve.
Camera travel speed can be set. There is no speed limit. I’ll demo this later in the video.
Atmosphere can be toggled on 2 different levels. Atmospheric fog, height fog and sun position can all be fine tuned outside of the gui, to roughly match any condition.
Globe objects are almost ready to be set from the GUI. I just need to make more objects.
Lensing rate is something I’m experimenting with. You could call this the flat plane obscured cheat mode.
The rough formula is the rate x (distance in kilometers^2) resulting in a percentage increase in size. The target object is simply scaled accordingly, from the same center point.
Whether or not this is actually occurring in the atmosphere, to what degree and under what conditions, is debatable. This will definitely be something to explore in depth in the future with real world tests.
Switch for “standard refraction” curve cheat mode. This doesn’t use actual refraction, but sets the Earth diameter to 7/6 and adjusts the ground and objects accordingly. This lines up to the Metabunk curve calculator refracted drop values.
Swell gives each section of generated ground a random difference in draw elevation between 0 and the value here. This represents waves and ocean water swell which would vary over the surface of the water.
3d modeled refraction. So far I have 1 layer customizable. This is a flat plane that can be positioned at any height between the viewer and object. You can set the thickness and refractive index.
I’m not claiming this to be what is actually going on with what we see, but by modelling different scenarios, I think we can get closer to the truth.
But I have to admit it was pretty easy to get this effect. This to me would represent a layer of less dense (lower index) warm moist air above the lake, below a layer of cool dry dense air. I’ll be doing a full video on this very soon.
And the final feature, auto-curve! All this does is set the camera to adjust height and angle relative to the curve, as it travels forward. This is equivalent to what airplanes have to automatically do, which avoids constantly flying up.
I’ll do more videos comparing fly ups at different speeds. But for now, here’s a quick fly up at ISS speed over lake Pontchartrain, no refraction, auto-curve on.
I’d like to start doing a live show every once in awhile where I just model anyone's requests as best I can. I’ll also try to model any requests left in the comments, during these live shows.
More to come!
