spherical projection

To talk about anything else
Post Reply
User avatar
slowtiger
Posts: 2190
Joined: 08 May 2008, 21:10
Location: berlin, germany
Contact:

spherical projection

Post by slowtiger » 21 Oct 2013, 10:49

Have a look at this sketch:


This was done via the new spherical projection script in Anime Studio, but the same feature exists in most 3D programs. I always wanted to use this for painted backgrounds, but never found some useful grid for it. So I did one myself, here it is for everyone to use:
Image

The image used for the example above:
Image

The bookshelf in the back is something I did quite a while ago and re-used it already in different projects. Import the image into TVPaint and use the warp grid with some good resolution, I used 7 horizontal and 6 vertical points. Select columns of points first (marquee select) to shift horizontally in place. Then place the points so the connecting lines meet or follow the grid lines.

Maybe I'm a bit obsessed with the clear lines, a more painterly approach could be better. Looking forward what others do with this!
TVP 10.0.18, Mac Pro Quadcore 3 GHz, 16 GB RAM, OS 10.11, QT 7.7.3

User avatar
Elodie
Posts: 13912
Joined: 06 Jan 2009, 09:53
Location: Metz

Re: spherical projection

Post by Elodie » 21 Oct 2013, 13:01

As the content sharing is dedicated to .tvpx with brushes, features and george function, I moved your topic :)
Questions or problems regarding the forum ? Please contact me by PM
Question regarding TVPaint or need a quotation ? Please contact me by email

User avatar
Cardin Collins
Posts: 42
Joined: 06 Sep 2010, 17:59

Re: spherical projection

Post by Cardin Collins » 12 May 2018, 11:48

I'd like to try this out.

It sure seems simple enough but I'm a bit confused about how to line up the points. @Slowtiger, could you elaborate on the steps please? Or anyone else that might know how to set this up.
TVPaint PRO 11.0.8 (64bit)
1 - Desktop: Intel Core i7-3770K CPU 3.5GHz, GeForce GTX 750 Ti, 16 GB, Win 10
2 - Tablet/Laptop: Sony Vaio Flip15a - Intel Core i7 (4th Gen) 4500U / 1.8 GHz, NVIDIA GeForce GT 735M, 16 GB, Win 10

User avatar
slowtiger
Posts: 2190
Joined: 08 May 2008, 21:10
Location: berlin, germany
Contact:

Re: spherical projection

Post by slowtiger » 12 May 2018, 12:53

You have to learn the grid. Start with a simple subject, like inside a room which is just a box.

You'll notice there's red and green grid lines. A red vanishing point is orientated 90° to a green vanishing point, there are 4 vanishing points in the grid (half a green one left and right). I've named them N E S W (north east south west) here. All verticals are straight, to make things easier, and also because that's what a spherical projection expects.

We look north and want to create our first wall. Start with 2 verticals equally distanced from one vanishing point N. They should be of the same height. Since N is red, you need to use the green lines for the horizontal parts of the wall.
grid1.png
The wall at the east side is 90° to the north wall, so for drawing its horizontals we need to use the red lines now. Of course the grid can't show all possble combinations, so you need to draw between the lines, but you're used to that from inbetweening.
grid2.png
I chose to make the south wall further aways, that means I draw a smaller "rectangle". Again the verticals are equally distanced from the S vanishing point.
grid3.png
Last step is the west wall, just follow the red lines.
grid3.png
Render this and watch in spherical projection: you'll be inside a box, east and west walls equally distanced from you, north wall closer than south wall.
Attachments
grid4.png
TVP 10.0.18, Mac Pro Quadcore 3 GHz, 16 GB RAM, OS 10.11, QT 7.7.3

User avatar
Cardin Collins
Posts: 42
Joined: 06 Sep 2010, 17:59

Re: spherical projection

Post by Cardin Collins » 12 May 2018, 13:32

Ah! Thanks for breaking it down for me, sir. The visual instructions are very much appreciated.

I'll do some tests and share once I have something worthy to show!

Thank you, SlowTiger!
TVPaint PRO 11.0.8 (64bit)
1 - Desktop: Intel Core i7-3770K CPU 3.5GHz, GeForce GTX 750 Ti, 16 GB, Win 10
2 - Tablet/Laptop: Sony Vaio Flip15a - Intel Core i7 (4th Gen) 4500U / 1.8 GHz, NVIDIA GeForce GT 735M, 16 GB, Win 10

Post Reply