Tell me more ×
Game Development Stack Exchange is a question and answer site for professional and independent game developers. It's 100% free, no registration required.
up vote 5 down vote favorite

In the Minecraft source code, this code is used to create a direction vector for a ray from pitch and yaw:'

float f1 = MathHelper.cos(-rotationYaw * 0.01745329F - 3.141593F);
float f3 = MathHelper.sin(-rotationYaw * 0.01745329F - 3.141593F);
float f5 = -MathHelper.cos(-rotationPitch * 0.01745329F);
float f7 = MathHelper.sin(-rotationPitch * 0.01745329F);
return Vec3D.createVector(f3 * f5, f7, f1 * f5);

I was wondering how it worked, and what is the constant 0.01745329F?

share|improve this question

2 Answers

up vote 4 down vote accepted

It works by using spherical coordinates. In particular see the section about converting to Cartesian coordinates. The Wikipedia article uses a slightly different convention for the definitions of the angles than your code, resulting in some sin / cos factors being swapped, but it's the same idea.

share|improve this answer
up vote 1 down vote

0.01745329F is the conversion rate between degrees and radians. Degrees are easier to understand but most mathematical functions need radians so this is a common conversion to perform. The -pi part just rotates the value further.

I'll let someone else address the trigonometry part. :)

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.