Degrees in 3D

[royibernthal]

A bit of a stupid question, but here I go - 

How many degrees are there when viewing 3d content? I'm not sure if degrees is right term.

For instance, we have a 3d object in a 3d scene. We can rotate it 360° horizontally, and 360° vertically.

Does it mean a 3D engine can provide a 720° view of objects?

[jellix]

sorry ...? Not sure what u mean.

[royibernthal]

For instance, in this animation you see the car doing a 360° horizontal spin:

https://www.youtube.com/watch?v=PA0yF0w_hwU

In addition, in 3d you are also capable of doing a 360° vertical spin.

Does that mean in 3d in general you can view an object from 720 different angles? Or am I not looking at it correctly?

[GameMonetize]

Do you mean: mesh.rotation.y = Babylon.Tools.ToRadians(720) ?

[royibernthal]

No  It's a general question about how many angles exist in 3d, rather than a practical bjs question.

I imagine my description is not clear, to say the least, but I'm really struggling with how to ask this question differently.

[MarianG]

I think 3d means that there are 3 axis, and you can rotate with 360 on each axis.

[royibernthal]

True, thanks for the correction.

So since we can do a 360° rotation around each axis, does it mean the combined number of angles from which we can view a 3d object is 360*3=1080?

[X3MC2]

There is no such thing as a 1080 °, the maximum angle in Math is 360 °, multiplying it by 2 or 3 has no effect, you just go back to 0°

Take a look at this 

 

 

[royibernthal]

Makes sense, but did you understand my question and what I'm trying to understand?

[X3MC2]

Just now, royibernthal said:

Makes sense, but did you understand my question and what I'm trying to understand?

No, not really. Rephrase your question if possible

[royibernthal]

From how many angles can you see a 3d object?

[dbawel]

The question I believe everyone wants to know before answering... is why are you asking? What is the usage for this information? Are you intending to build a game, or app; and why is the question of possible angles of viewing asked? I would look at the following link on this forum for many possible answers to your very relative question:

Once you are able to tell us how you will use the info requested, perhaps we might understand what the question actually is. There is no actual limit to the # of angles in which you can view and object, as it's all relative - unless you preface the question by asking how many possible "camera" angles in whole numbers. But first you must fully understand Yuler angles (Pitch, Roll, and Yaw) to begin to understand an answer to what appears to be an extremely vague question.

DB

[royibernthal]

I can explain further, but it's not much of a big deal for me to know the answer, and it feels like explaining what I mean will be harder than knowing the answer is worth.

Let's forget this question, thank you for your time

[X3MC2]

7 minutes ago, royibernthal said:

From how many angles can you see a 3d object?

Here is your answer :

https://www.reddit.com/r/explainlikeimfive/comments/1z6z2n/eli5_how_many_degrees_does_a_sphere_have_if_a/

Quote

Your question is a non-question. It is meaningless to extend angle-measure into dimension 3+, because angles are a planar object.

However, there exists a concept in non-Euclidian geometry known as the “solid angle” that you may wish to look into. While we understand that angle measure and the associated units (degrees/radians) to be dimensionless, for a system of dimension N, it's associated angulation is of dimension N - 1. So for dimension 3, angulation is 2-dimensional. That is to say, solid angles are measured in square-degrees/steradians. In a sphere, there are 4πsteradians, or 129,600/π square-degrees.

 

[royibernthal]

Yes that answered my question, thanks.

[JohnK]

2 hours ago, royibernthal said:

True, thanks for the correction.

So since we can do a 360° rotation around each axis, does it mean the combined number of angles from which we can view a 3d object is 360*3=1080?

If you allow only 1° rotations then there are 360 possible rotations around each of the three axes so there are 360 * 360 * 360 possible combinations. If you allow 0.5° rotations there are 720 * 720 * 720 possible combinations. Theoretically since rotations are continuous there is an infinite number of combinations, in practice in a computer project you would restrict the amount of rotation allowed. If you  only allow 10° rotations then there are 36 * 36 * 36 combinations of rotations around the threes axes.

Also in code rotations are usually measure in radians not degrees so if you only allow rotations of PI/n radians since 2PI is a full turn there are 2n * 2n * 2n possible combinations.

[gryff]

@JohnK: TY you John!!

I was starting to wonder if I was not understanding the question properly.

cheers, gryff

[royibernthal]

My question could be interpreted in 2 different ways due to the way I asked it (not on purpose).

They both answered different interpretations of it, but JohnK understood what I was trying to say and gave me the answer that I was really looking for.

Thanks John.