AuthorTopic: Problem with top-down orthographic elliptical objects  (Read 821 times)

Offline Deidara

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Hello,

This must be a really newbie question but I cannot find any good rules of thumb or resources on how to draw elliptical objects in a top-down orthographic projection. All that comes to me is that the "back" part of the circle needs to be flatter than the "front" part, but I cannot envision this even after looking at existing artwork.  ???
The object in question I am trying to make is a yurt. It looks well enough on its own but when applied to the rest of the image it looks really off because of the difference in perspective. Would appreciate some pointers on this.



Offline Deidara

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Re: Problem with top-down orthographic elliptical objects

Reply #1 on: May 24, 2017, 07:47:06 am


The top is what I came up with after looking at some tilesets and applying it to a flattened tent shape.
Is this kind of the right way?

It's quite problematic that there doesn't seem to be a single right use of this projection.
For example Zelda games also show the back part of roofs as half tiles, where as other games hide the back of roofs completely.
Both look good, even though the same camera is uses so one of them should be "wrong".

Offline Cyangmou

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Re: Problem with top-down orthographic elliptical objects

Reply #2 on: May 24, 2017, 08:55:53 am
the elllipse should be 4:3 in ratio

Here you have the calculations / tut
http://cyangmou.deviantart.com/art/Pixel-Art-Tutorial-4-3-4-cylinders-and-cuboids-329318036

check out "Tower 57" which i illustrated, I am fairly sure that all objects in it are angled the right way:






Zelda breaks projections in multiple ways for gameplay
stuff like Earthbound and similar games uses 45 top down, but in many cases not a realistic approach to shape and volume.
Which means characters are drawn nearly from the front, while some things appaear seen from the top, it's not consistent but it usually works if the angle difference is not too strong.
THat being said the more realistic the style, th emore those things matter.
"Because the beauty of the human body is that it hasn't a single muscle which doesn't serve its purpose; that there's not a line wasted; that every detail of it fits one idea, the idea of a man and the life of a man."

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Offline Tycho Magnetic Anomaly

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Re: Problem with top-down orthographic elliptical objects

Reply #3 on: May 24, 2017, 09:51:49 am
Hi, just caught this post about orthogonal projections which I am also sort of struggling to find a consistent technique for. I am working on a JRPG type game, but unlike many in the genre my game is not conforming to a grid or tile based system.
I have discovered by working with this and observing other games that there is a lot of foreshortening on "some" things and brute forcing of angles to make a playable game. I find also walk behind areas, structure height difficult to work with too with this perspective.

Here is a work in progress of a small section of a city, and as you can see I have had to really battle with every building to make them sit down properly, and many of them are way off and just would not make sense in a 3D space.

http://fractalscapes.net/-DUMP/FORUM/city_test34.png

I have even tried to test a method of box modeling the stuff in 3d, then using that to trace over the pixel art, but I am finding in 3D you have to squash, stretch objects out of original proportion so it looks correct when rendered at orthogonal.

In short I have still not discovered a good method to this and I am winging it all the way. My hope is the sum of all the messiness might be enough to disguise all the issues.

Even still, and from looking at many other games, I don't think there is a sure perfect answer for this and I suppose it also depends on the application of what your doing, such as if its for a game context, or animation..etc


That tower 57 is mind blowing dude

I shall read up on your tutorial Cyangmou, perhaps this might help me find a good consistent technique.

Offline Deidara

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Re: Problem with top-down orthographic elliptical objects

Reply #4 on: May 24, 2017, 12:20:47 pm
Great link, exactly what I was looking for! Thanks  ;D
This is the new result.