View Full Version : Creating Polys for Front Projection Maps

09-22-2009, 07:26 PM
I find it easy to have my Lightwave models cast shadows on a plane. But I am pulling my hair ou... (cliche' alert)

I want the saucer to cast shadows on video footage of a number of buildings.

Is there any software that helps. Should I re-shoot the footage with a normal lens? I have the 20x and the 3x wide angle zoom for an XL-2.

I tried modeling polys in the shape of the buildings - but it was a time I tell ya.

09-22-2009, 08:04 PM
Have no clue...
But looking forward too see how that ends =)

09-22-2009, 08:30 PM
Gawd probiner. It's been a long time since geography classes. Portugal looks absolutely stunning.

09-23-2009, 03:16 AM
well I think that you really have to model a simple shape for the buildings, so there's some geometry to catch the shadow correctly or else it won't follow actual geometry. Then use front projection on this geometry and maybe use blochi's (www.hdrlabs.com) shadow catcher node tree

09-23-2009, 04:23 AM
to create realistic shadowing (distortion, hiding etc.) you would need real geometry, so re-modeling with low-poly objects to create a shadow pass would be the way. Autodesk ImageModeler (formerly Realviz) http://usa.autodesk.com/adsk/servlet/index?id=11390028&siteID=123112 could be a helper.
The spectrobes: origins project from the actual newsletter shows a little making-of of the compositing http://www.newtek.com/lightwave/newsletter.php

09-23-2009, 04:41 AM
for a shadow catcher ..just model something nr the same proportions
there's a whole chapter on in lightwave inside books...most of them...just blow off the dust and browse thru them!

searched for the vid on the newtek site but it's a 404 page now...is there an update due??

only found this...

09-23-2009, 05:08 AM
if i'm readig you right...

make a ground object you need shadows catching on
make a proxy object you need shadows catching on
load in your background plate in the viewport...

move and sort out your camera to match up with the bg plate...it will help
if you took measurments of the scene and know the camera lens type and the size and distance of objects in the real scene such as buildings...

match up the scene...this could take a while!

select the ground and any objects you want a shadow caught on...
in the surface tab set them to shadow density....

now remove the bg footage so you don;t render it...
render out as png32 so you get an alpha....
and your scene will get shadows caught and your 3d objects will cast shadows on the fake ground/buildings...

take the result into a compositor and compt the bg and render together and color correct it.

09-23-2009, 11:22 AM
Thanks cresshead, zardoz, rsfd - everyone - I have some things to think about. I have to keep telling myself that fake storefronts are fine. When Lightwave first came out I was always trying to build everything - even though the cam wouldn't see it! Shhesh.

Last night I started making some single poly objects and lining them up. That appears it will work - but I really have to look into these other ideas. Compositing in AE has always been fun for me.

Thanks again.

09-23-2009, 05:51 PM
from Proton's vids,... http://www.newtek.com/forums/showthread.php?t=77002


Introduction to Compositing inside of LightWave:

Introduction to working with Foreground Images in the Compositing tab:

09-23-2009, 07:27 PM
yeah that's do the job!

09-23-2009, 10:30 PM
Plenty to study there guys. Thanks. I almost wish I could get the devil's (Autodesk) software, but 1000 bucks. Not now, not ever. (Oops. Shouldn't have said that.)

Anyway, I understand the basic ideas of front projection mapping. Although William's tut that showed front projection within a node was new to me.

The scene around the corner from me seems simple, but! It would be a lot easier if I had a large expanse of asphalt and a plain pole to deal with. :D

In this example. I spent lots of time just tweaking 1 poly at a time into position. But there are a lot of different angles and objects that I would like to see interacting with the 2 characters (Big Saucer and Little Saucer).

Three badly placed polys at least shows what I am trying to accomplish.

And here's Peaches playing hide and seek with me peeking around the stairs.

09-24-2009, 02:48 AM
what I usually do in this situation is use google maps to draw the polygons over the map to get the right proportions, then I extrude it and move the roof polygon to the right height for each building.

09-24-2009, 07:42 AM
It's a lot easier than it sounds unless the whole shot is in motion, that's another story.

You can model in modeler, sync layout, and in layout you can remodel, distort, etc until things appear to line up right. It doesn't have to be perfect, it just has to be believable.

There's a whole video on scene extension that's completely applicable.

Even if you're not extended the set...
this goes over some down and dirty shadow catcher creation,
and there are some tricks using a cube and soft dynamics in one
of the many Lightwave videos here on this site.

Real trick though is not to over think this one...
again, it's so easy depending on the complexity of the shot but yours doesn't look like a killer.

Hope this helps.

09-24-2009, 10:48 AM
All this helps of course. I did have in the back of my mind doing a dolly move, etc with my XL2, after I had a handle on these first shots.

So far I've figured out tracking motion with zoom in AE and using the image only for effects combined with the 3d saucer. (Not perfectly fine tuned I know - but that's at the end.)

This latest idea has been so troublesome because I eventually want to move both the real world and LW 3d camera around.

I'm gonna try that Google Map idea. I hope they've got better images than the last time I looked. (Thanks Zardoz)

And lwaddict, Thanks too. It just has to be believable is true, especially it it's easy ;o)

09-24-2009, 07:57 PM
It appears that Google hasn't updated their maps for a number of years. At least here in Oregon on the coast.

09-24-2009, 10:42 PM
I decided to play with a halloween scene and get away from front projection for the moment and as a result I was putting together a scene that was moving right along fine untilI added a small patch of ffx grass.

Look at the volume light ina background.

Is there something about ffx that causes that?


09-25-2009, 05:22 PM

Here it is in motion. At least I'm having fun because it's all 3d - well, except the After Effects stuff.

I could see putting some motion on the ffx grass in the foreground so it looks like the AE rain is hitting it.

If I have to, I'l get rid of the volume light in lightwave and comp one in.