Blow Shadow Projector ... casts shadow on floor AND ceiling

Unity Engine
1

I’m wondering what I’m doing wrong here.

The blow shadow projector is not above the object in question (as you can see from the top screenshot).

I also have noticed some odd behavior with Physics.Raycast sometimes hitting something in the exact opposite direction (I’m using it to detect the first object between the camera’s desired position and its target – and placing the camera in front of any obstacle … sometimes the camera suddenly pops out PAST the target.

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2

This has come up before. Are you using falloff?

http://forum.unity3d.com/viewtopic.php?t=3156&highlight=blob+shadow

AC

3

I’ve noticed this too in the past and have posted about it… falloff doesn’t really work with the projector. Any “hints” from the OTEE crew? This “bug” has been around since 1.2.2 I think.

4

Yep, in the demo I just posted, if you’re on the rooftops and watch the helicopter go underneath a “bridge”, you can see the shadow on top. The falloff sort of works but I couldn’t completely get rid of the “above” shadow despite my best efforts.

–Eric

5

Works for me… the trick is to have a black pixel in the falloff texture (and set it to Clamp), so that the whole opposite-side-projection does not contribute to the image.

6

Clamp! Duh, I figured there was something simple I was forgetting (I kind of thought I did have it working at one point…). Thanks for that. :slight_smile:

–Eric

7

Hmm. I was just using the blob shadow projector in standard assets with no changes.

Oddly enough, when I went back, the problem disappeared. Perhaps I accidentally hosed some setting.

8

mmm, I’m not sure. Here’s an example of all things considered so far… a black pixel in the falloff, clamped etc. and I’m still getting a double.

Dunno, the ceiling in this model is a single poly with it’s own UV but it isn’t built into the rest like the floor? Wonder if that has anything to do with it?

M

9

In the cases I showed – in every case the stray “top” shadow is appearing on scene geometry.

Unfortunately, I’ve tossed out that entire scene so I can’t recreate the problem exactly any more – but, as I said earlier, I was using the default blob shadow projector, with its – presumably correct – bitmap.

10

OK, so I built the ceiling up into 3d’s; the same shadow now appears on the roof, as it were?

m