I have always wondered how people made momentum tests in Hammer. When I say momentum test I mean tests that you either jumped off a ledge into a portal with the other on a curved surface, or when you do the same thing with a faith plate. The only part I have trouble with is finding out where you are supposed to land. Is it just guessing and checking? The first time I attempted to do this I made a trigger_catapult in front of the curved section, set threshold check on, and just guessed on the range for it to work. It worked but also didn't work. I wanted it to be less of a trick, unless that is the right way, in my map. So basically I am wondering how far off I am, and maybe a little advice on what I should try if I am wrong.

Well, for the catapult, you want to use an info_target so the player will launch towards the target. The Mapping Wiki has more info about it. As for regular flinging (momentum through portals), it's a guess and check thing.

As ml said then it's called flinging and it's much about guessing. If you jump off a high place you will have to find out how high it should be, by trying and trying.

If you use faith plate make the plate (as they do the mapping wiki) a little away from a diagonal wallpanel. Place the target on the panel, and make the faith plate launch at the target. Now you can change the player speed to see what works best. Also here: try try try!

Tip: high speed = low height
Low speed = high height

You can put an info target where you want the player to hit, and set the catatpult to fling to there. (like lagger said)

Glados actually explains this very well in the first game. You can use her rules of portals to create momentum jumps without catapults.

GLaDOS wrote:
Understand how a portal affects forward momentum, or to be more precise, how it does not.

Momentum, a function of mass and velocity, is conserved between portals.

In layman's terms, to jump a distance of 256 units in game, you will have to fall into a portal from 256 units above. This will give you the same jump distance because the gravity is the same on both sides of the portal and will negate itself almost evenly.

Hope this helps.

iWork925 wrote:
Glados actually explains this very well in the first game. You can use her rules of portals to create momentum jumps without catapults.

GLaDOS wrote:

Understand how a portal affects forward momentum, or to be more precise, how it does not.

Momentum, a function of mass and velocity, is conserved between portals.

In layman's terms, to jump a distance of 256 units in game, you will have to fall into a portal from 256 units above. This will give you the same jump distance because the gravity is the same on both sides of the portal and will negate itself almost evenly.

Hope this helps.

This will also help me figure this out. I was going to create a test with catapults parented to the portals and see if I could change the targets using func_portal_detector, but this makes it easier for the simple parts.

The VDC's article on flings indicates that > Quote:

Debugging tools are available in Portal 2 to visualize predicted flinging arcs.

Conveniently, it doesn't say how to access them. Anyone know how to do that?

BOB74j wrote:
The VDC's article on flings indicates that
Quote:

Debugging tools are available in Portal 2 to visualize predicted flinging arcs.

Conveniently, it doesn't say how to access them. Anyone know how to do that?

I only know that for catapults (taken from the vdw: "
As seen in one of the developers commentaries valve use visual trajectories to help debug and tweak the faith plates. In console type "developer 1" to enable the development environment and then type"ent_bbox trigger_catapult" you will now see a visual representation of the trajectories of every trigger_catapult in the map. If you want to just see a single trajectory type "ent_bbox ". ")

To show 'em all: just type ent_bbox trigger_catapult.

For normal flings, use iWork's method of calculation.
If that doesn't work, use a texture where you know the dimensions of (for example 1 block = 32px. and just count the blocks, so you can try in your map and then edit it in hammer if it isn't working properly.

Create a brush in Hammer, and as you drag it and change the size, the dimensions can be seen at the bottom. This will show you how many units high, wide and deep the brush is.