Direction Convention

[michael.zhang]

Hello,

 

I am confused by the idea of "direction" in the Unigine script API.

Node node = new Node();
node.setWorldTransform(mat4_identity);
vec3 world_d = node.getWorldDirection();

// vec3 = (0, 0, -1) // Direction seems to be by default forward -Z

 

Since Unigine uses a +Z Up axis, that seems somewhat unintuitive.

I would've expected +Y to be, or +X to be the default direction.

 

For example, when you set a persecutor's phi and theta angles to be 0, it's facing down the +X axis.

 

 

 

Michael

[steve3d]

+Y is default forward direction in unigine.

check this:

https://developer.unigine.com/forum/topic/239-serious-bug-in-softimage-export-plugin/

[ulf.schroeter]

+Y is default forward direction in unigine.

check this:

https://developer.unigine.com/forum/topic/239-serious-bug-in-softimage-export-plugin/

 

Unfortunately player camera default frustum orientation (when world transform does not define any rotation) is in -Z direction. It really would be great to have an all-encompassing consistent convention for modelling (+Y definies longitudal axis of body e.g. car length axis), cameras (+Y defines forward frustum orientation) and character movement frame (+Y defines forward movement).

[michael.zhang]

Unfortunately player camera default frustum orientation (when world transform does not define any rotation) is in -Z direction. It really would be great to have an all-encompassing consistent convention for modelling (+Y definies longitudal axis of body e.g. car length axis), cameras (+Y defines forward frustum orientation) and character movement frame (+Y defines forward movement).

 

Thanks for the response Steve. As Ulf said, I'm talking about an all encompassing convention.

THough, I suspect at this point it would be difficult to change since it would break code in alot of places.

 

At the least, document it clearly when a class' forward direction or a function's direction return is not using the same +Y forward convention as the engine's coordinate system.

[michael.zhang]

Yah, so show why this convention is annoying:

 

+X is Foward for Player Actor movement

-Z is default camera direction

+Y is Forward in terms of unigine coordinate system +Z up