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View Full Version : Setting up a 2 point perspective



piotir
09-07-2006, 03:02 AM
How do I do? Using LW9...

kruemel_1
09-07-2006, 05:09 AM
2 point perspective means it is projected towards two points - you look at the edge of a box, the camera placed at the height of the middle of the edge.
So to get a 2 point perspective from a house, the camera has to look at an edge of the house and has to be at the middle between ground and roof level.

piotir
09-07-2006, 05:30 AM
36682

Do you get parallell vertical lines like in the attached image?
And how do you set up your camera, FoV?
My aim is to map 3d models into 2-point perspective hand drawings.

Exception
09-07-2006, 06:44 AM
Go to this thread: Linki (http://www.newtek.com/forums/showthread.php?t=50364&highlight=tilt+shift+lens)

Download the tilt shift lens james wilmott made...
Install it in plugins directory, add it, select it as a new camera.
It removes vertical perspective.

piotir
09-07-2006, 07:42 AM
Thanks that helped a bit.

But... with a horizontal FoV of 110 it starts to look odd.
I would like to have a true 2-point perspective camera...

Explanation of different types of perspective:
http://www.geocities.com/hamchoba/animex/3d.htm

jameswillmott
09-07-2006, 07:58 AM
Of course it looks odd with a 110 degree fov, most renders will.

Providing you don't bank the camera, it IS true 2-point perspective. You'll just have to play with the angles until you get the look you're after.

piotir
09-07-2006, 08:41 AM
Yes I know but what shall I do?

In extreme angles the only work around is to use very high FoV and the tilt plug.

jameswillmott
09-07-2006, 08:56 AM
Can you post a render for us? We might be able to make some suggestions.

piotir
09-07-2006, 10:36 AM
I just did. The two images in this thread are two examples.

Integrity
09-07-2006, 05:48 PM
An angle of 110 degrees and looking down will be three point perspective not two. This is what I'd suggest on how to do it...

Since two point perspective is for when the viewpoint (or camera) is parallel to the ground you will need to have the camera at a pitch of zero at all times (assuming you set up the ground in your model where up/down is on the Y axis). In order to be able to look "down" with parallel verticals your scene and what your looking down at will have to be in the bottom half of the frame (with the camera at pitch zero), then use the Limited Region feature of Lightwave's renderer so you don't waste time rendering whatever you have in the top half of the frame (double your original render heighth). If you cannot get everything into view as you like due to doing it this way then just zoom out a little more. Note you can also move things around, up/down and even rotate things but keep the pitch of the camera at zero (assuming you're in the right coordinate system).

I would also suggest looking into the new camera tools in 9 (I am using 8, make sure you're using the "Classic" camera in order for my suggestion to work) to see if it allows you to render perspective in two dimensions and parallel in the other. This way would make everything a lot easier.

I was not able to look into the plugin that was linked but all it does is taper (resample) the render right? This isn't true two point perspective as you have said.

jameswillmott
09-07-2006, 07:06 PM
The plugin doesn't resample the render, it removes tilt so that the camera is parallel to the ground, and then applies a shift to the lens to look where it was originally, which maintains true two point perspective. ( In 9 only, doesn't work in 8.5 and lower )

This is essentially the same as using the double resolution / Limited region trick but it is much easier to set up and use.

piotir
09-08-2006, 12:59 AM
The new Advanced camera works nice for panoramas, fisheye and so on but i canīt manage it to render a 2 point perspective. One problem is that you have to render all the time to get a qlue of how the settings looks.

I want a camera that allows you to render perspective in two dimensions and parallel in the other.
quote: -This way would make everything a lot easier.

jameswillmott
09-08-2006, 01:12 AM
I just did. The two images in this thread are two examples.

Sorry, I didn't realise. They look like 2 point perspective renders, what's the problem?

This is a render using the camera plugin... ( the top image is, the bottom is 3-point perspective just for comparison )

http://www.newtek.com/forums/attachment.php?attachmentid=34272&d=1152663179

...how is this not 2 point perspective?

piotir
09-08-2006, 01:33 AM
I couldn't follow the link. But if you check the link i posted earlier you see what i mean by 2 point perspective.

I get the feeling that they (my posted images) get distorted along the depth axis.
Some kind of "strech" because of the high FoV.

Exception
09-08-2006, 07:08 AM
Piotir, Those images look as expected, but I think you might be wanting an isometric view... you want a non-perspective view. The distortion you mention is correct perspectival distortion. It's supposed to be there. James wilmott's camera is an accurate 2 point perspective tool, but for isometric, ortographic, planometric, axonometric and all those, you need to use the ortographic camera and look up in a book what the angles are for each respective setting. (if you care about accuracy) The usual one (isometric) is at 45 degree angles of the subject's corner lines.

Edit:

Here, a decent explanation of axonometrics; Isometric, Dimetric, Trimetric...
http://www.compuphase.com/axometr.htm
http://en.wikipedia.org/wiki/Axonometric_projection

piotir
09-08-2006, 07:29 AM
no, not isometric. that does the advanced camera in Lw manage just fine.

I have now tested another image using the tilt shift lens and I noticed that in the most extreme angle (left & right side) and if the camera is pointing down... it should look like this (earlier posted image), it will be distorted.

Many thanks for all the help!

Exception
09-08-2006, 09:44 AM
I have no idea what you're talking about anymore :)

I must say, those drawings are really nice.