Uneven surface

[Ian Stark]

Hope this makes sense! I'm a fairly basic AE user (CS3).

I have created a large pseudo-3d flythrough with the following elements:

Ground plane - i.e. a solid layer
Sky 'backcloth' - another solid layer
A bunch of still photos and other graphics (12 stills and around 20 graphic elements, some of which are animated in sub-compositions)
A camera which flies through the elements
Various lights.

This is an intro sequence to a video prospectus that my client, a school, has commissioned me to make for them. It has the look and feel of all their corporate material - still pictures of kids set amongst numerous cartoon elements (flowers, insects, clouds etc).

It looks OK for a first attempt but I have one problem and one question:

Problem: I have set the stills etc to cast shadows and this they are doing, BUT in some cases (not all, that's why it's so frustrating!) the shadows simply will not 'connect' with the shadow casting element. It looks as though the element is hovering slightly above the ground plane - which it isn't! All elements cast shadows OK, just not always in the right place. Any ideas?

Question: The ground plane is, surprise surprise, representing grass, but at the moment it is a completely level, plain green surface. Is there anything I can do to make this surface more interesting - i.e. adding some gentle slopes etc?

I suspect I will have more questions tomorrow but now it's 1.15am here and I am trashed! Any help with these issues much appreciated.

Cheers.

Ian . . .

[Jim Montgomery]

Question: The ground plane is, surprise surprise, representing grass, but at the moment it is a completely level, plain green surface. Is there anything I can do to make this surface more interesting - i.e. adding some gentle slopes etc?

You might try a displacement map with fractal noise.

http://www.videocopilot.net/tutorial.html?id=27

[Alex Sprinkle]

Is there an alpha channel on your images that aren't casting the shadows correctly? I'm wondering if there could be some transparency at the bottom, which would be like glass casting a shadow (in essence).

Something else to try is drawing a quick mask around those layers and THEN adding the shadow back on (for testing purposes at least).

Lastly, are there other effects on those layers in front of that effect? If so, drag that effect to the top of the effects listed.

Dunno if that helps at all

[Ian Stark]

Jim: thanks for the suggestion and the link. Looks like I'm about to embark on my first ever use of a displacement map!

Alex: There are no other effects on those layers but your other suggestions sound like very strong candidates. I'll investigate as soon as my third cup of coffee kicks in.

Thanks to both of you for taking the time. I'll report back.

Ian . . .

[Daniel Ross]

Showing a preview/stills would be helpful.

[Ian Stark]

Originally Posted by Daniel Ross

Showing a preview/stills would be helpful.

Yeah, I expected someone would ask that, and yeah, it would help to describe the issue.

I wish I could, but I can't!

The pictures are of young kids, real kids that attend the school (the school being my client). We (obviously) had to ask parents to sign a release form and on that form we undertook not to use any of the images of their children in any way other than for the video - and explicitly agreeing not to post them on the web. This was following advice we sought from the CPA here in the UK.

So, 'fraid not!

Anyhow, looks like between Jim and Alex we've got it sorted. Thanks anyway.

Ian . . .

[Dale Stoltzfus]

Could you just do a quick-and-dirty blur to obscure the faces of the children? Or even a face-sized solid tracked into the footage to cover up their heads.

[Ian Stark]

Hi Dale,

Forgive me for being over cautious but I am contractually bound not to use the photos anywhere else and I'm not really comfortable playing around with my obligations to my clients. On top of which, I told them I wouldn't! These people are spending many thousands of pounds with me and I don't really want to do anything that will put their nose out of joint. Although it might be verging on the paranoid, this is a paraphrased extract from the guidelines we were given:

"While it is obviously inappropriate to publish pictures of children where their identity may be determined and possibly used in 'grooming' . . . even obscuring a child's features is insufficient. The content of the photo could be used or adapted for inappropriate use. This kind of adapted material has appeared on child pornography sites."

It's a sad world, I know.

The video is being used to kick off an open evening for parents interested in sending their kids to the school(s). Each family will receive a copy of the video but it won't be posted on the web or made available to subsequent enquirers. The people who send their kids there are VERY wealthy, including a number of major film stars, rock stars, overseas royalty and global business leaders! You'll understand they take security and anonimity very seriously!

I appreciate it's not always easy to visualise an AE problem and I guess I shouldn't expect very informed responses! As it is, the replies I've had have been of great use.

Again, sorry to be so reluctant about this. Hope you understand.

Cheers,

Ian . . .

[Dale Stoltzfus]

Hmm... sounds like you don't really have any room to move! Ah well - good luck with your project.

[Ian Stark]

You should see the restrictions on the video I'm making about sheep farming . . . . ;-)

[Jim Andrada]

Could you replace the kid pictures with pictures of - oh, let's say, your dog?

Two thoughts,

One - if the problem doesn't show up again, there could be something amiss with the photos themselves.

Two - This might let folks who know about AE help diagnose the problem in situ.

Discalimer - I know very little about AE (Trying to learn)! but have been trying to fix software problems for 50 years.

[Giroud Francois]

you probably have a golf green near this place, so make a shot of real grass with a high pixel count digital camera , zoom in it and make a loop of it.
you can put a red tape of paper in the grass to key the join in the loop

[Alex Sprinkle]

Originally Posted by Giroud Francois

you probably have a golf green near this place, so make a shot of real grass with a high pixel count digital camera , zoom in it and make a loop of it.
you can put a red tape of paper in the grass to key the join in the loop

Red tape of paper? I don't follow. What does this mean/do?

[Ian Stark]

Alex - yep, some alpha left at the bottom of the picture! Now removed and all is well. I had to ditch a couple of the pictures though because there are kids standing behind each other, with those at the rear looking as though they're floating. Didn't think about that until I had removed that spare alpha space at the bottom. Duh!!! Many thanks.

Jim - as you suggested, there was something amiss with the photos (see above) and I'm annoyed I didn't think of it myself! After the weekend I'd be happy to post up a before and after example using my dog - no wait, my poor old dog died in 1983. Wouldn't look so good. Could I use one of my cats?

Giroud - golf course - inspired idea! But I too am confused a little by the red tape suggestion. Can you clarify please?

Thanks to all for your kind and generous help. Nice weekend to ya.

Ian . . .

[Giroud Francois]

just imagine you get the grass filling the bottom of the screen, the top of screen is the sky.
if you need to loop the video, this join between sky and grass must be transparent to let see next grass (not sky). It is the same as you mentioned with raw of peoples. the last row (head and shoulders) must let see the row behind (that you will add in post) , so it must be keyed.
since sky is blue, grass is green, a good choice for the key would be red.
as for people, you just need the key background to cover the tallest people, then you can complete the missing background with a plain garbage mask made from the computer.
if you are lazy, the better to put a synthetic grass carpet on a big roll, and shoot it with the cam as it roll for ever.