How can I create a page turn effect?

</first_post_humility>Firstly, thanks to all the forum’s contributors for letting me stand in the shadows and consume the never ending stream of knowledge that is contained in their posts…thanks :smiley: </>

My question: How do I create an effect which looks like a page being lifted at one corner and turned over, leaving the other side face-up at the end?

Some background: I’m thinking about how I might create an effects plugin for Vegas Video (a video compositing app) which would allow Blender to be used for speacial effects in a similar way to Borris Red and Hollywood FX. In these systems, the host compositing app launches en external effects app with the selected video tracks. As part of my analysis, I’m trying to see where the limitations are by trying to emulate common effects … one of which is the “page peel” where one video track is “peeled away” to reveal another underneath.

Any thoughts?

ok one thing you could do, im sure this is not the best way of doing it but you could take a plane and subdivide it a few time then make a key animation by making the plane fold a little bit every few frames until it is completely folded. Again I beleive there might be a better way of doing it but this is what I would probably do in my range of knowledge about the subject.

Thanks Falconis. I tried something similar with a smoothed grid and armatures but the “page” (i.e. grid) didn’t bend smoothly which spoiled the effect. One thing to bear in mind is that the dimensions of the page can not change if the effect is to work i.e. you can fold a page and peel it back etc but you can’t stretch it or otherwise change its geometry (think of a sheet of paper)…this was what made me think of using the armatures.

how about a lattice deforrmation on a subd’d plane? or nurbs? (does lattice work with nurbs- should check it out)

greets

marin

Hmm…the search goes on…it seems to me that the main challenge is to maintain the geometry of the “page” i.e. if I pick up a piece of paper at the corner it doesn’t stretch or otherwise deform. Planes and grids don’t seem to offer the right behaviour (too many creases) and the level of subdiv needed to make a pane smooth is probably prohibitive.

I’ve started to explore the NURBS surface in 2.31a which seems to offer the correct dynamic but I need to figure out how to keep the page geometry constant.

The search continues…

did you try changing the angle of the smoothness that might help you

using bones might help. if you add a detailed (=lots o’ bones) chain across the page, you should me able to perform a very controllable pageturn. two important things:

  • think about bone layout, you might need several chains, and not necessarily lined up with page margins (flip a page a couple of times and look how it really defoms - it’s in a diagonal matter)
  • mesh resolution and weighting. smooth and round transform means a lot of weight blending across vertex groups.

pros: while bones deform, you don’t have any stretching, thus the plane should behave like paper
cons: complex setup with lot’s of objects.

ok enough theory and philosophy;) i’l try if i have time.

best regards

marin

You seem to be right, Marin, I tried some with lattices and got some stretching to handle. Will futher study tha lattice solution for this.

I was wondering if there is a way we can say “don’t let the edges change length in this mesh” i.e. I can move individual vertices but doing so will drag others in order to keep the edges the same lenght?

I would recommend using RVK animation. After you set the begining and end frames, maybe try using PET to get the in between ones, with a little alt S, and using the RVK sliders to tweak the influences. I made a thread in general that might be helpful with this,…it’s a method of using PET, entitled ‘I found a new sculpting method’, in case you feel like searching for it.

Don’t get so hung up on that the page should act excactly like paper,
focus on the motion rather than exact form of the page. You can get away alot with camera placement and a good timing with the animation.

Heres something i threw together:
http://www.thehive.se/blends/pageCurl.jpg190kb mpg

And the blend

/nozzy

Looks great Nozzy - thanks for the blend. How did you do it? Did you place each vertex individually?

I moved the pivot point of the page to left side and animated the page
rotation.

I set up 3 RVK’s which i built with the PET tool, ("O"and SHIFT + “O”)
and then used the RVK’s in both plus and minus to get the right effect
in the Animation.

Hope that helps :slight_smile:

/nozzy

Thanks for that Nozzy - I’m gonna go away and play for while now :smiley: