Shadows Cut Into Geo ?

BLOODCURVE

For Maya...

Other than by hand, anybody know of a plugin / script that will take a projected shadow ( from a spotlight, etc ) and cut my geometry up as required kind of like a stencil - for faking some shadow work ?

Thanks.

BLOODCURVE

Help !!

No one suggest anything, I was under the impression the Turtle renderer could do this, but I can't find any info in their page relating to this function ?

EDIT :

I need to project shadows of some sort onto a landscape - lightmaps are a no go - and vertex colouring just isn't detailed enough, I'm open to any other suggestions or tips / techniques that might help me achieve something better - shadows cutting into polys are quite destructive, so I'd be happy to hear alternative methods ?

Thanks

commander_keen

I wanted to make a maxscript that would do this at one point, it would be very useful. I doubt you will be able to find any released tool to do this though. BG&E used this method for their lighting and it worked quite nicely.

BLOODCURVE

Thanks, commander_keen

I could've sworn I had seen somewhere that Turtle could do this, or maybe it was another renderer, but it was some time ago when I saw it, and I can't seem to reference that info now.

commander_keen

I know max's default radiosity implementation can do something like this kinda. What it does is basically tessellate the geometry based on how much lighting detail is in the area, not actually cut hard lines based on shadow casting geometry, so its not very useful for games. I think that tessellated geo is temporary and you cant convert it to permanent geometry, I could be wrong about that though.

greyocto

back in the ps2 era one of the things I did for vertex color shadows was use the view from the light or have camera that matches the light and cut shadow silhouettes of the objects into the ground and other objects. You could add another loop of edges along the transition to soften the shadow too so you don't have to make the shadow as detailed and specific and you can even create falloff effects. If you can afford the transparency you can float alpha geo over the ground rather than cutting in. You can take a small texture that is like a box that has built in soft edges and map this floater geo to get soft edges and even fake some gradation towards the interior of the shadow. Or a few nice rendered shadow cards (like say a tree shadow for under trees) can work really well if you have a lot of the same objects (like parking meters or something).

Steve Schulze

You could do it in ZBrush.

Grab a black and white render of your shadow, make yourself a fairly dense plane in Z, project the silhouette on as a mask and then delete the remainder.

Alternatively, you could project it into the Shaodowbox thing to generate your mesh.

BLOODCURVE

I think I may end up doing something with melscript, I came across a script on highend3d ( creativecrash ) that will create a stencil on an object based on another objects geometric profile, if I can somehow calculate and possibly convert to geometry the shadow volume, then I can utilise the stencil scripts functions to then perform the cut. Another possible alternative method would be to take the highest points - the overall objects that will project the 'bigger' shadows, remove lower geometry, i.e. if it is a building - only keep the roof area - then extrude based on the roof area in the direction of the shadows - then use that geometry combined with the stencil function to create my shadow cuts. Smaller objects within my level will be standard floating polys created by hand - i.e. trees / lamposts, etc.