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Questions tagged [3d]

3D refers to three dimensional space where coordinates are represented with X, Y and Z values.

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7
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2answers
936 views

Perspective in early pseudo-3d games

Please take a look at the screenshot below, from the old classic Space Harrier. My question regards the curved perspective on the chequerboard 'ground'. It's got a strangely curved geometry (I ...
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3answers
2k views

How difficult is it to implement 3D models in a 2D game?

Creating a full blown 3D game requires a lot more math for physics, but what if I just want to mix 3D models in a 2D game, such as in the New Super Mario Brothers? Would I be able to get the looks of ...
7
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4answers
10k views

How do I fix this weird lighting problem?

I'm making a small game in Unity, and some models are displaying very ugly shading. The shading usually looks funky along the edges between triangles. I'm pretty new to working in 3D; I bet this is ...
7
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3answers
998 views

3D collision-detection middleware [closed]

(I've split this question into two. For 2D, see: 2D collision-detection middleware) Are there any recommendable middleware available for 3D collision detection? I believe I've heard Bullet has a ...
7
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1answer
588 views

Display Lists in OpenGL

I heard that there was a faster method of displaying vertices, rather than recreating the GL_TRIANGLES, each time the scene is drawn. I thought I read somewhere that this method was obselete. Why ...
7
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3answers
3k views

Optimizing Octree Rendering

Say I have an octree and at a certain level I store VBOs in that octree. I know the dimensions of of the nodes that own the vbo so I can do basic frustum culling. That works nicely because everything ...
7
votes
2answers
2k views

Procedural rock algorithm

I'm looking to create some procedural low poly rocks and boulders for a game. I haven't found much interesting information on the internet other than 3D software articles. Not sure what way to go.
7
votes
3answers
950 views

Pre-render 3D object from multiple angles, save as PNG

I'm looking for a tool or script that takes a 3D object (any format) and makes multiple renders of it automatically (using a raytracer or other high-quality offline renderer). It would then save the ...
7
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3answers
6k views

How does the Unity3D entity system work?

I saw the Java Artemis Entity Component System and thought of the entity system in Unity3D. In Artemis for example you can only add one component type to each entity and the logic is not in the ...
7
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2answers
4k views

How do collision meshes work in games like Zelda on the N64?

I was recently reading about the technology of Ocarina of Time/Majoras Mask and discovered that world collision is done using a single triangle mesh (vertices, normals, etc) for an entire area. There ...
7
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4answers
1k views

Face-Click Detection ( like in Minecraft )

I am working on a box-based game engine like minecraft and I was wondering how to detect the "clicked face" when placing blocks. I have created this engine in C++ ( DirectX / D3D ), C# ( XNA ) and ...
7
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3answers
5k views

How to texture a surface generated by marching cubes algorithm?

I'm working on a voxel game, and I have some problems with texturing. I have read the related questions on this stack exchange, but they seem adressing a generic problem (using triplanar texturing), ...
7
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2answers
12k views

calculate new vertex position given a transform matrix?

How can I get the new position of my vertex given a 4x4 transform matrix or simply 9 floats (positionX, positionY, positionZ, rotationH, rotationP, rotationR, scaleX, scaleY, scaleZ)? Usually I can ...
7
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5answers
2k views

Path planning for volumes in games

How would you path plan a volume for a game? For example a 1 km cube with tunnels and caverns. Also the terrain is destructible. You have walking and flying modes. I would separate it into phases. ...
7
votes
3answers
9k views

Maya 3D model to iOS OpenGL ES

I need to display, rotate, and zoom a 3D model in OpenGL ES (iPhone/iPad). The 3D graphic artists are using Maya (on OS/X). What export format should I be looking at to use their 3D models in the ...
7
votes
1answer
5k views

What is the fastest algorithm to check if two cubes intersect (where the cubes are not axis aligned)?

I am looking for an algorithm to check if two cubes intersect. One can check if each of the 6 faces of cube A are intersected by each of 12 edges of cube B, but that is 72 checks. I've heard there is ...
7
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3answers
1k views

How do I target a tank turret with an offset barrel?

I have a tank model consisting of multiple parts, a body, a turret and the barrel of the gun. The turret is offset from the body origin and can rotate around the Y axis(up). The barrel is connected to ...
7
votes
1answer
182 views

Shadowmap granularity

I thought that we could re-use the same shadowmap for every light. But I've seen an industry article suggesting that you can't re-use shadowmaps between lights, and have to use separate surfaces. Do ...
7
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2answers
3k views

Vector games (Wireframe, Elite-like) theory and implementations?

I'm interesting in knowing more about how vector games like Elite and Star Wars Atari were built from grounds up. The question is not how to implement vector graphics with modern 3D APIs like OpenGL ...
7
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1answer
8k views

Understanding the perspective projection matrix in OpenGL

Setting the Perspective projection matrix in Open GL (including OpenGL ES 2.0) has the following general format: ...
7
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3answers
716 views

Sort Polygons in order - not working?

I'm fairly new to programming in a 3d world. I'm trying to create a canvas where all the objects are drawn in order of furthest-to-closest and from bottom to top - so they don't overlap each other, ...
7
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1answer
1k views

How to make a 3d beam effect with XNA 4.0?

Do you know any demo or tutorial to learn to make a 3D Beam effect? I have learn to make a 2D laser by simply using a texture and moving it thru screen. But I am a little bit lost while trying to do ...
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2answers
2k views

Vertex data split into separate buffers or one one structure?

Is it better to have all vertex data in one structure like this: class MyVertex { int x,y,z; int u,v; int normalx, normaly, normalz; } Or to have each ...
7
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3answers
12k views

Generating island terrains with Simplex Noise (C#/XNA)

I've got one little question: Is there any code or sample which shows how the simplex noise works? I cannot find anything about it... How should I implement it, without the knowledge how the algorithm ...
7
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2answers
2k views

Blood splatters on a terrain

I am trying to create blood effects, where the characters being killed are on an uneven terrain. The simple way is to instantiate a prefab with texture, which uses a plane mesh, on the raycast hit ...
7
votes
1answer
2k views

How can I extrude a regular, grid-based 2D shape to 3D?

I have a list of vertex coordinates which encircle several 2D areas. Orthogonal lines only, but not necessarily convex areas... similar to PCB traces of conductive copper areas. I want to draw them ...
7
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0answers
549 views

How to create skeletal animation data for a skirt?

Please think of this in an engine-agnostic way first, and then we can talk about specific engines. In my game, I have a 3D character which is wearing a hakama (think of it as a long pleated skirt). ...
7
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2answers
3k views

Matrix rotation wrong orientation LibGDX

I'm having a problem with matrix rotation in libgdx. I rotate it using the method matrix.rotate(Vector3 axis, float angle) but the rotation happens in the model orientation and I need it happens in ...
7
votes
2answers
1k views

Displaying text on a 3D plane

I am busy with a pet project where I am trying to create a Collectible Card Game in 3D. These cards have Hp and Damage etc. but I cannot find a way to neatly display these values. I tried to use a ...
6
votes
4answers
3k views

What is the simplest way to calculate distance in a 3D environment?

What is the simplest way to programmatically calculate difference between two points in a 3D game environment? I am trying to sort a list of light sources by how close they are to an entity, so that ...
6
votes
6answers
9k views

Most efficient 3d depth sorting for isometric 3d in AS3?

I am not using the built in 3d MovieClips, and I am storing the 3d location my way. I have read a few different articles on sorting depths, but most of them seem in efficient. I had a really ...
6
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4answers
531 views

Would like some help in understanding rendering geometry vs textures

So I was just pondering whether it is more taxing on the GPU to render geometry or a texture. What I'm trying to see is whether there is a huge difference in rendering two scenes with the same setup: ...
6
votes
3answers
6k views

Why / how does XNA's right-handed coordinate system effect anything if you can specify near/far Z values?

I am told repeatedly that XNA Game Studio uses a right-handed coordinate system, and I understand the difference between a right-handed and left-handed coordinate system. But given that you can use a ...
6
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3answers
3k views

What are the big advantages of shaders ? What is doable with them, and what can't be done without them?

I don't really know when vertex and/or pixel shaders became available for consoles and computers, but what could we do without them ? I don't really understand what is achievable with shaders and what ...
6
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3answers
2k views

Character Animation Architecture

Can anyone explain the general architecture typically used for 3D character animation? Are movements like walking and falling scripted against the skelton, and simply executed on input? If so, is ...
6
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2answers
987 views

Is there an efficient way to identify in which run-time generated room a character is, in a non-grid 3D environment? How?

Here is what I am trying to implement. I wrote a script that allows the player to place walls during run-time, in non grid-based 3D environment (walls can be diagonal with rotation increasing/...
6
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2answers
697 views

What will AMD Fusion or likewise hybrid CPU/GPU will change for the 3D programmer ? Are they potentially faster?

Since the early days of accelerated graphics, programmers were obligated to use hardware-supported libraries like directX or OpenGL. If we wanted to explain someone what happened by introducing a ...
6
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2answers
2k views

Calculate an AABB for bone animated model

I have a model that has its initial bounding box calculated by finding the maximum and minimum on the x, y and z axes. Producing a correct result like so: The vertices are then stored in a VBO and ...
6
votes
1answer
15k views

Blender - exporting .obj with texture coords

I'm writing a game which uses obj files. I created an object in blender and I applied texture without UV coordinates and my question is: how to export this object to obj file, but with texture ...
6
votes
3answers
2k views

What's a good way to check that a player has clicked on an object in a 3D game?

I'm programming a 3D game (using C++ and OpenGL), and I have a few 3D objects in the scene, we can say they are boxes for this example. I want to let the player click on those boxes to select them (ie....
6
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3answers
5k views

How do I implement flat shading in GLSL?

I'm working with GLSL and trying to implement flat shading on a 3D model (rather than smooth shading). To illustrate what I mean, here are two screenshots of cubes in Blender. Here's one with flat ...
6
votes
2answers
3k views

Triangle-triangle continuous collision detection

I am making a 3D game engine and I use continuous collision detection. I am using Sphere-Trees to cull primitive collision checks to a minimum. However, I'd like to perform continuous triangle-to-...
6
votes
3answers
4k views

Modelling photo-realistic grass in realtime

I see a number of tutorials on how to create good looking grasses when creating 3D renders but can't think how to model it for realtime/use in a game's scenery. Sure simple models with alpha cutouts ...
6
votes
2answers
306 views

Self-righting agents that have fallen over

I need insect-like agents that have fallen/rolled on their back/side to naturally re-orient themselves. The agents are modeled as simple cuboids in the physics engine (Bullet) to approximate an ant-...
6
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2answers
150 views

Shading Languages vs Materials in 3D editors

There are many 3d packages which are able to construct materials. Autodesk Maya, 3ds max, Houdini, etc. There are languages which are able to construct materials as well, like GLSL and Cg. How does ...
6
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2answers
9k views

How to customize a character with new objects (clothes, body parts) in a 3D game?

how do we customize a character in a game by adding, for example, a different clothing? The character has an armature, made in Blender, if I add a new object with the game engine, I would have to copy ...
6
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2answers
13k views

Making holes in 3D objects (Unity)

How can I make a hole in an object with Unity 3D? I've something like this object and I want to make a hole in it.
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3answers
3k views

How difficult and expensive would be to obtain 3D models for my game? [closed]

So, basically I'm looking for a way to get some 3D models and animations for my game. I know this is kind of vague, but I don't need a precise answer, the details would be like this: The 3D models ...
6
votes
4answers
837 views

Is Frustum Culling by itself enough for Consoles and Mobiles?

Software occlusion culling is often expensive, especially for smaller and older devices. Is frustum culling alone adequate on systems that can optimally display 10k triangles at most? If not, are ...
6
votes
1answer
468 views

Running geometry shader only once

(Unfortunately couldn't find the answer myself) Does a neat way to cache the geometry shader results in Direct3D10 or OpenGL ...