Questions tagged [portals]

a doorway or opening that connects two areas of the game space, even if those areas aren't adjacent & aligned in the physical layout of the environment. Players can typically see and move through the portal into the linked space. Portals were most famously used in the Valve's Portal game series, where the player can shoot linked portals onto various surfaces and traverse between them to solve puzzles.

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representing transforms without a world/global reference frame

Background: I'm trying to make a segmented/portal-based game engine that supports impossible (non-euclidean?) geometry. By segmented/portal-based I mean the world is divided into segments which are ...
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Recreating A Puzzle Effect Using Stencils

I'm trying to recreate something I saw on reddit a while back. I tried rendering camera output onto planes, but am not getting the results that I want -- this is basically what I'm trying to recreate: ...
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Impossible rooms in 3D games

recently I was playing The Stanley Parable, and noticed that there are several impossible spaces in the game - in this example, a pair of pillars in the middle of the room, which from each side appear ...
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Rendering portals using stencil buffer

Due to this question I have changed the method of rendering portals. Before I was using FBO and rendering to a texture, but somehow I failed. Now I switched to a stencil buffer method. My problem is ...
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1answer
697 views

With what projection matrix should I render a portal to a texture?

I'm using OpenGL. I have problem with my engine's portal implementation. To create the first portal I do: create a virtual camera with the position of the second portal and the correct orientation ...
4
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1answer
186 views

portal cutoff effect

I want a 3D Mesh to come out of a flat portal. Only the part of the mesh that's coming out of the portal should be rendered, so the mesh should be cut off or sliced until it's fully outside the portal....
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1answer
2k views

How does a segment-based rendering engine (as in Descent) work?

As far as I know Descent was one of the first games that featured a fully 3D environment, and it used a segment based rendering engine. Its levels are built from cubic segments (these cubes may be ...
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872 views

Pathfinding with portals? [closed]

I'm not making a game with portals in it (one way or bidirectional). These portals instantly teleport characters from one location to another. How would I implement pathfinding? Here's an animation ...
3
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1answer
236 views

How Do Objects Not Clip Out the Back of Thin Walls When Put Through a Portal?

In Portal or Portal 2, let's say you pick up a cube and put it most of the way through a portal on a very thin wall. The cube should clip outside the backside of the wall. How does Portal do this, or ...
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2answers
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How to blend two cameras when traveling through a portal in Unity3D

Before I get to my question, I know the most obvious solution would be to use the normalized view port rect, however I need more complex shapes than a rectangle, and I've looked in to using the view ...
9
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1answer
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How to create high quality and fast portal effect?

EDIT: So I've gotten the portal visual effect working with no performance hit, and I've got the physics set up of objects with rigidbodies moving through portals seamlessly, and objects with character ...
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3answers
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How to implement collision detection of portals?

For example, take this scenario (excuse my horrible drawing skills): This is based on "Portal", where the stickman is going through the blue portal (which is linked to the red portal), but there is a ...
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2answers
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Is there anything equivalent to Portal 2's linked_portal_door in any other engines? [closed]

I need the functionality of the linked_portal_door that's in Portal 2. I've searched a little in UDK and mostly got people trying to duplicate the portal gun. Does anyone know if UDK, CryEngine, ...