When I have the maggot at 100% (the size it comes in from Cinema 4D as, which is about as tall as M4) everything is fine.

When it shrink it to its final size of 2%, and use any lights with Depth Map Shadows, I get a square block for a shadow.  Ray traced shadows are ok.

Is this an issue for any tiny prop and Depth Map Shadows?  should I just put big warnings on it that you can't use it with Depth Map Shadows without bad results?  Or is there anything I can do in the material nodes to avoid this?

Thanks so much for the help. :)

Known problem - they won't fix.

It's tiny scenes, not tiny props. If you put anything else in the world and it's at least a couple feet away, the problem disappears.

Nobody cares about depth-mapped shadows with a single tiny prop anyway.

Quote - Known problem - they won't fix.

It's tiny scenes, not tiny props. If you put anything else in the world and it's at least a couple feet away, the problem disappears.

Nobody cares about depth-mapped shadows with a single tiny prop anyway.

thanks so much!  it drove me crazy wondering how to fix it.  

There was another thread recently with the same problem. 

I wonder what the "min size" is, because I've made several small props and never encountered it myself.

I've never had this issue before either, but I also haven't really used something this small either.  I think the smallest we have created prior to this is a pen, and that was no problem.  But a pen vs a baby fly (sounds so much better) is quite a bit bigger.

Single light with default Depth Map settings.  The animation runs the Bee's scale down from 1000 to 100.

Might call the animation "Bee There or Bee Square."

In the last frame (Bee Square) the Bee measures 0.04 PU from front to back. 

In the previous frame she's 0.08 PU from front to back.

Dividing the frames farther, it appears that .05 is There, and .04 is Square.  Doesn't seem to depend on the distance between the Bee and the Ground, only on the size of the Bee.

Thanks for that Ockham. So anything bigger or equal to  0,5 PNU is fine.

What's that in millimeters? :)

Just to be clear, it's 0.05 not 0.5 PU.  The latter is about the height of a typical human figure.

0.05 PU is 130 mm or about 5 inches.

Quote - Just to be clear, it's 0.05 not 0.5 PU.  The latter is about the height of a typical human figure.

0.05 PU is 130 mm or about 5 inches.

Nice to know, thanks for sharing!

Unfortunately, I don't think I could get away with a 5" maggot. :)

Well, you could always scale it up to 50 feet and recast the scene as a monster movie.  Eeeeeewwww!

Or, you could just forget about Depth Mapped shadows, which are pretty damn useless anyhow. :)

I'm putting two info thumbs that warn about the issue, in case someone does want just tiny objects in their scene, and depth map shadows, to turn off casting shadows.  That way, if they get the same thing, they won't wonder what is going on.

Quote - There was another thread recently with the same problem. 

 

I wonder what the "min size" is, because I've made several small props and never encountered it myself.

Wow - Rendo ate my second post on this - the one where I linked to an earlier thread with much more info. I posted it hours ago, but it disappeared.

Well - I'll try again. Look here:

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3639699&ebot_calc_page#message_3639699

Quote - I'm putting two info thumbs that warn about the issue, in case someone does want just tiny objects in their scene, and depth map shadows, to turn off casting shadows.  That way, if they get the same thing, they won't wonder what is going on.

Read my linked post. Two tiny objects ten inches apart - no problem.

Never tell somebody to turn off shadows. Instead, tell them to use ray traced.

Quote - I wonder what the "min size" is, because I've made several small props and never encountered it myself.

You don't remember talking to me in the other thread from 2010 on this same topic? I quote you:

Quote - May 5, 2010 - But it's an interesting bug, this. One I've never met in the wild myself so I'm intrigued! And now I know how to avoid it, should I ever encounter it!

Quote - Read my linked post. Two tiny objects ten inches apart - no problem. Never tell somebody to turn off shadows. Instead, tell them to use ray traced.

Thanks, I will do that.

A shadow map is a precalculated lattace or raster that is used to map a shadow into a scene. it can be more efficient than a ray traced shadow (time wise) but at the expence of memory usage. The importand thing to be aware of with a shadow map is that the ammount of allocated memory is split accross the total cone of the light. So the wider the cone or the smaller the map size (memory allowance) the fewer the squares in the raster (note the word squares).

the renderer checks every element in the raster to see if there is geomitry between the light and a surface. if so it then projects that raster element (square) as a shadow into the scene.

If you can see a square then that meant that the raster is too small and it needs more elements to make a more accurate shadow.

in the attached image you can see on the small sphere how the 256k raster projects a single square into the scene and the shadow doesn't get reasonable definition till its using 2Mb. Conversly with the large sphere you can see the lack of definition of the curved edge even at 2mb (the squares are clearly visible).

I hope that sheds some light on things :)

No it doesn't. You completely misunderstood what is being demonstrated.

My shadow map was 2K. Go read the other thread more carefully.

Repeating from my other thread... the problem is a bug in creating the shadow map when your entire scene fits in a 9 inch box or less. It has nothing to do with shadow map resolution.

Two tiny props, 9 inches apart - broken shadow.

Same scene, same settings of everything, but props now 10 inches apart - shadow is now correct.

As already stated there is a scene bounding box issue with Infinite Lights using Shadow Maps where at a certain point the light just casts a huge shadow into the scene. I found that this bounding box was approximatly 0.1 PU in size (with the light flat on to the scene). However if I tried to find the exact point the broken shadow would actually creep into the scene. (see attached).

I found that adding in a 2nd item just outside the critical distance (0.11PU) and removing render attributs wouldnt fix the problem. HOWEVER if I kept ALL its shadowing attributes but moved it below the ground plane out of sight the scene then rendered correctly. Not a fix but a simple work arround.

Quote - > Quote - I wonder what the "min size" is, because I've made several small props and never encountered it myself.

You don't remember talking to me in the other thread from 2010 on this same topic? I quote you:

Quote - May 5, 2010 - But it's an interesting bug, this. One I've never met in the wild myself so I'm intrigued! And now I know how to avoid it, should I ever encounter it!

Sadly I didn't remember that thread at all. My memory is a bit wonky at times :( And it's not that I didn't see the last reply, as I myself made the last post in that thread :(

Guess my memory is worse than I thought :(

Thanks for reminding me of it though :)