Wintermute Engine Forum

Wintermute Engine => Technical forum => Topic started by: Derrek3D on October 21, 2007, 02:06:32 PM

Title: A question of perspective
Post by: Derrek3D on October 21, 2007, 02:06:32 PM
Hello, I have a question regarding perspective in a picture.

When I render my scene, the objects on the sides of the resulting image tend to "lean" inward towards the center of the image. I'm talking about objects that if rendered from a different angle they would have looked normal, of course.

Now my question is, when I place a 3D actor on that scene in the engine and the actor moves near one of these "leaning inward" objects (let's say, a building), would the actor "lean" as well and stay parallel to the building or will he remain in his normal angle - something that would cause the whole scene to look unrealistic?

I hope I'm explaining this clearly enough...
Title: Re: A question of perspective
Post by: Jyujinkai on October 21, 2007, 03:56:49 PM
as far as i know you can not do things like fish eyes and stuff.... but you can use FOV of your camera to warp the rendering of the 3D image... though i would imagine this would not be enough to mimic complex things like you said...

Title: Re: A question of perspective
Post by: Derrek3D on October 21, 2007, 04:23:53 PM
I wasn't referring to fish eye effects and the likes, I'm referring to a normal scene. I'll see if I can find any screenshots from some recent games to demonstrate what I'm talking about.
Title: Re: A question of perspective
Post by: Derrek3D on October 21, 2007, 04:57:12 PM
Ok, here is a screenshot taken from the upcoming WME-based "Art of Murder": http://www.adventure-treff.de/images/bild.php?bild=screenshots/kunstmordens_1.jpg (http://www.adventure-treff.de/images/bild.php?bild=screenshots/kunstmordens_1.jpg)

Take a look at the street lights on the left and on the right of the scene. For reasons of perspective, they lean inward towards the center of the scene. Now if Nicole Bonnet (the actor) was to stand near the street lights on the left, for instance, will she also have this "lean" towards the center of the screen or will she look exactly the same as when standing in the center of the scene?
Title: Re: A question of perspective
Post by: Stucki on October 21, 2007, 06:39:20 PM
no i think she will be standing perspectivly correct to your render, because your walk plane and your camera contain all relevant infos.
Title: Re: A question of perspective
Post by: Jyujinkai on October 21, 2007, 08:30:14 PM
yea.. like i said if the warping is solely based on the FOV and Lenz size of the camera, it should do it.. but complex warping can not be done.
Title: Re: A question of perspective
Post by: Derrek3D on October 22, 2007, 11:17:07 AM
yea.. like i said if the warping is solely based on the FOV and Lenz size of the camera, it should do it.. but complex warping can not be done.
I'm sorry, Jyujinkai, but don't understand what you mean. I'm not very familiar with the terms you use yet...

no i think she will be standing perspectivly correct to your render, because your walk plane and your camera contain all relevant infos.
Thanks, Stucki, this is most reassuring. Do I need to do something in the scene in order for this to work or will it work automatically?
Title: Re: A question of perspective
Post by: Stucki on October 22, 2007, 01:56:46 PM
for my experiences all you have to do is import the 3ds file ( with correct named cameras, lights, walkplane and shadow objects ) and import it in your scene.
create the geometry file and adjust the camera value in scene editor 3d settings by hand.
this should do it

Title: Re: A question of perspective
Post by: Mnemonic on October 22, 2007, 08:32:58 PM
Yes, since the 3D character is viewed by a camera with (ideally) the same parameters as the camera that was used to render the background, the same perspective projection applies.
Title: Re: A question of perspective
Post by: Derrek3D on October 23, 2007, 03:32:47 PM
Ok, thank you everybody for the answers!