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animated video texture with alpha that cast shadows?
I am trying to bring in an animated image. In this case, a silhouette of a person. I have created my model and set up an environment that mimics a light source coming through a window and hitting the focus area, which in this instance, is a logo. I would like to be able to insert an animation I made of a person walking back and forth and have it cast a shadow onto the scene. I have tried using the camera mapping feature to try and project the content from the angle of the main lightsource. This worked well as the camera mapping provided me with a source point to project my image but the image travels through my window shape where it should be blocked by the window shape’s surfaces. Also i can not seem to get my image to behave like a normal texture. It seems to hijack the texture of which ever surface it is being projected onto.
I also tried using a light source and texturing it with the same image, but this proved to be random at best and came no where close to the desired effect.
I tried creating a plane and putting my image onto the plane. As the image has an alpha, this worked well as it created a perfect image with negative and positive texture but alas when I set that up in front of my light with the hopes of it casting a shadow, it just appeared to the light source as a completely transparent surface and no shadows where cast.
I am sure there must be a way to do this but my experience with c4d is limited and I can not think of another way to approach this. If I was trying the last method listed above in aftereffects, I would simply be able to adjust the shadow transparency and it would create a shadow based on that setting but I can not seem to find an equivalent with c4d as the shape itself doesn’t honor the texture mapped onto it in regards to casting shadows.
I can provide a link with screen caps if that helps.
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8 Replies
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It should cast shadows, assuming that you have shadows turned on for the light.
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what are you referring to? The camera map or the plane with the animated texture that has a light shinning through it?
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I was referring to the plane.
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here are some screen caps to give you a better idea of my setup.
The wireframe setup
with out anything in the window frame
using camera mapping
using light texture
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in my tests, i used a still frame png. Could this be the reason that the light treated the plane with a texture as an alpha, as if it was invisible, and shined right through it?
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wow i stand corrected. You are right. I just tried it again and it works! ugh. Spent a whole day on this a few days ago with no luck and now I try it again and it works! Sorry about that. Thanks for making me try it again 🙂
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NP. Been there done that. 😉
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Ah this is a problem for me… not entirely solved. R12. If I use a spot light or any light in the scene, shadows are cast correctly from the texture map on a plane.
If I use ambient occlusion, the shadows are still there but AO ONLY works on the plane, not the alpha’d texture, so I get a shadow of the (invisible) plane, not the footage.
This seems to me like a massive oversight in C4D – I mean this is surely a common practice – to pull in a bit of footage as an animated bit of the composition.
I do it all the time in AE. It seems a bit mad to have to throw it on a plane as a texture rather than an alpha object in its own right.
Perhaps this is sorted in later versions – moot anyway because I can’t afford an upgrade, and do not want to upgrade illegally.
Is there a better solution that this above?
Thanks for any help
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