Incorrect @N size

[prat391]

Hi all,

I am in the process of trying to make a procedural building system and have seemed to encounter an error. I have a very small piece of vex code that is deleting top and bottom-facing prims by checking if their @N.y value is <0 or >0. 

 

vector ynorm = @N;

if(ynorm.y > 0 || ynorm.y < 0){

removeprim(0,@primnum,1);
}

A few primitives which should have a @N.y of 0 value have incorrect values like -5.67663e-0 or -1.0457e-07. This is causing primitives that should not be deleted, to be deleted. How can I correct these normal values?

[dleonhardt]

Those values are most likely rounding errors. In cases where like here the values are very very small, I would just give a small tolerance to the if statement. So something like:

if(ynorm.y > 0.0001 || ynorm.y < 0.0001)

 

[acey195]

On 8-12-2021 at 9:40 AM, dleonhardt said:

Those values are most likely rounding errors. In cases where like here the values are very very small, I would just give a small tolerance to the if statement. So something like:

if(ynorm.y > 0.0001 || ynorm.y < 0.0001)

 

Yup never rely on floats with == checks

a further alternative would be something like:
 

if(abs(dot(ynorm, {0,1,0})) > 0.001)

or if you want to set a specific angle:

if(acos(abs(dot(ynorm, {0,1,0}))) > radians(<angle in degrees>))