Why don't use a constant instead of Clamp here?

ViaCognita · June 29, 2016, 5:59pm

I’m learning Unreal Engine and I’m very confuse why clamp is used here:

I think Clamp always will return 2. Why don’t use a constant instead of ViewSize to Ceil to Clamp?

Why are they using Clamp when it always returns 2?

You can find the complete material [here][2].

anonymous_user_dcd9d04a · June 30, 2016, 2:35pm

i don’t know much about clamp but i guess
clamp is used to make the value come between the value( 2-1 in this case) the value can be 20 or 30 but clamp helps to get the value between 1 and 2 in this case, i don’t know much about view size but it’s an input value which can be anything (even 30 or -0.1) so to get that to be what we want we use clamp

rnerlin · June 30, 2016, 2:56pm

I’m fairly positive after looking at this that they intended to use a normalize to range here. ViewSize gives a 2Vec, so unless ViewSize-Ceil has a weird interaction under the hood, there is no reason to ceil-clamp here (as far as I can tell).

anonymous_user_dcd9d04a · June 30, 2016, 3:03pm

ceil and view size

anonymous_user_dcd9d04a · June 30, 2016, 3:13pm

just tried it :

high value i guess.

anonymous_user_dcd9d04a · June 30, 2016, 3:23pm

try it yourself if you are interested (could be useful to me, maybe to you as well?)

ViaCognita · June 30, 2016, 3:21pm

Yes, it is very strange and confusing.

ViaCognita · June 30, 2016, 3:28pm

Yes, I’ve been trying it and it always returns 2.

anonymous_user_dcd9d04a · June 30, 2016, 3:31pm

are you using clamp? well the value is high so it will use the highest possible i guess.

anonymous_user_dcd9d04a · June 30, 2016, 3:32pm

as you can see in my answer without clamp the result is …high

ViaCognita · June 30, 2016, 3:40pm

Thanks, but your answer doesn’t help much. That is obvious.

anonymous_user_0df12f74 · June 30, 2016, 3:48pm

Agreed, with a non normalized value it will always be 2 unless the ViewSize is 1x1 or less.

Doesn’t make any sense, probably a mistake on their part.

anonymous_user_0df12f74 · June 30, 2016, 4:05pm

The value will always be 2 unless the ViewSize is less than or equal to 1x1, which doesn’t make any sense. It must be a mistake, I cant think of any reason why you would want to do that.

As nnerl1n mentioned above, they were likely meaning to use a Normalize node between the ViewSize and Ceil but forgot to add it. This way makes a little bit more sense, but is still an odd way of finding a multiplier for line thickness.

Either use a normalize or just a constant, or even ignore all of it and double the input scalar value. =)

anonymous_user_dcd9d04a · June 30, 2016, 4:07pm

agreed .

ViaCognita · June 30, 2016, 4:19pm

Thanks. So, I can use my common sense with Unreal. I was thinking that there was a hidden reason to use those three nodes.