Stupid Question, Is CGI Made Of Triangles Just Like Video Games?

[Gizmo j]

I know that video games are made with triangles and was wondering if it's the same thing for CGI.

 

[[DHT]Osiris]

I know that video games are made with triangles and was wondering if it's the same thing for CGI.

This is actually one of the less stupid questions you've asked.

No, not necessarily. There's many techniques for making CGI, most of which I'm unfamiliar with, but I know enough to know they're not all (or maybe even any, anymore) triangles.

 

[Gizmo j]

Anyone else with some insight?

 

[Red Squirrel]

I used to play around a bit with 3D rendering and really basic animation but that's going back decades and it was nothing serious. Seems to me everything is based on either triangles or rectangles, to some degree. Even something like a cylinder is just a prism with many faces. I'm not sure how other effects work, like explosions, fog, smoke etc. I don't imagine they are tiny models as it would be super intense to render so it's probably it's own thing.

 

[darkswordsman17]

This is actually one of the less stupid questions you've asked.

No, not necessarily. There's many techniques for making CGI, most of which I'm unfamiliar with, but I know enough to know they're not all (or maybe even any, anymore) triangles.

Here's someone with a similar question with some explanation. I was thinking that even games were moving to quadrangles for primitives over triangles as it made tessellated meshes, and the ensuing rendering (texturing, applying deformation or movement - think cloth moving, and culling) easier. I think this happened fairly recently.

Why are quads used in filmmaking and triangle in gaming?

In film school, in the classes of 3D modeling, I was told that when we model something for films we maintain topology of 4 edged polygons. Any polygon which has more or less than 4 edge/vertex is

computergraphics.stackexchange.com

 

[Gizmo j]

What about STL files for 3d printers, are those made of triangles?

 

[Red Squirrel]

Just readup real quick on STL, from sounds of it, it does look like it's triangle based. Basically it's telling the printer to go from one point to the other in 3D space to create triangles, and all the triangles together make up the object. TBH I did not figure it worked that way, I figured it would be based on a number of 2D layers. I presume the printer itself takes the STL file and then translates it into 2D slices internally though as physically that's how it prints.

 

[igor_kavinski]

I think this happened fairly recently.

Aware of any game engines that have made the switch to quadrangles?

 

[darkswordsman17]

Aware of any game engines that have made the switch to quadrangles?

I wasn't able to find the video that I'd seen (somewhat around the time this thread was originally made), that talked about that change in game development (which I believe was occurring around the time they started supporting the various mesh stuff with quads being easier to work into the meshes I believe? Seemed the two were connected), but it seems games will ultimately convert them to triangles because that's how GPUs render. Its more that most modern game engines now support models built from quads (so you could import them natively into say Unreal Engine), but ultimately it'll convert them to triangles (by basically splitting them into 2-3 triangles), so seems kinda only half-true that games do quads now. I also saw something saying Renderman (Pixar's rendering engine) used to be based on quads but it actually does triangles now due to ray-tracing, but I don't know how true that is.

 

[igor_kavinski]

How the Kindness of Sega Saved Nvidia from Going Under | Hacker News

news.ycombinator.com

So Nvidia's first GPU was a quadratics processor.