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When you first enable Ray-traced rendering AE brings up a warning that says that effects and blend modes do not work on the 3D layers.
To blend the shadow with the background layer you need to use blend modes so the trick is to pre-compose a copy of the light that casts the shadow, your extruded text and your shadow catcher solid. Here are the steps:
- Duplicate your extruded text layer
- Set it to cast shadows only
- Duplicate your lights and if you have one, your camera
- Make sure the white solid is set to accepts shadows on and accepts lights off so that the layer stays pure white
- Pre-compose the duplicate lights, camera, extruded text and white layer and call it Shadow Catcher
- Your remaining extruded text layer and lights stay unchanged
- (Turning off cast shadows may improve rendering performance but the text may look better with it turned on)
- I added a pre-composed ramp to use as a Blur Map for camera blur to soften the shadows
Now set the blend mode of the shadow only pre-comp to multiply. This will do the trick. The technique is explained in several tutorials. Here's a screenshot of a quick example I threw together in 5 minutes. It actually took about as long to arrange the workspace to make the screen shot as it did to create the effect.
You'll find a this sample comp here.
Thanks for the thorough explanation and for providing your sample comp - very, very helpful. When I try to add a camera to your example and move around in the scene, the shadow does strange things. I'm trying to add a shadow catcher to a scene I created which utilizes an HDRI environment in ray-tracing mode. I'm trying to create a shadow underneath and behind my 3d text that moves with my camera animations. Am I missing something obvious and dead simple or am I trying to do something which goes far beyond your example?
I see a moving shadow being used in this tutorial, but the implementation of the shadow catcher used in conjuntion with an environment image and a moving camera in ray-trace mode is not explained.
You can find my scene file here.
You missed the part about pre-composing so you can use blend modes. Carefully look at the sample comp.
Hi Rick. Any thoughts about why the following would happen? To test the above, in Ray Traced render mode I built a very simple model (i.e. Light, Extruded Text, Solid Layer, Camera) and did everything noted, and did get a Shadow from the 3D Text to appear on the White Solid, but only with the Extruded Text visible; when I hit the switch on the Extruded Text Layer to Cast Shadows Only, the Extruded Text and the Shadow disappear. Since my Comp consists entirely of Graphic Objects, and therefore has no Video Footage, it seems that the Shadow Catcher feature available in Motion Tracking controls would not be applicable. In the scene I have, the 3D Text is spinning, so I would need the true 3D Shadow (i.e. only..) that is Motivated with a Light Source in the scene. After generating the Shadow, I would make it a Child of the Spinning 3D text, and then make all the other required adjustments to finesse it (e.g. Ramp, Reposition, etc. ).
I'm not sure that I follow you. I think you:
- Set you comp to Ray-traced rendering
- Added a Text layer
- Made the text layer 3D
- Added a solid layer
- Made the solid layer 3D
- Positioned the solid layer below the text layer and rotated it so that it formed a floor
- Extruded the solid layer
- Added a light with cast shadows turned on
- With the floor set to accept shadows and the 3D text set to cast shadows you see a shadow
- Added a camera
- With the text layer set to cast shadows only the shadow goes away, and that is the problem.
If 11 is true then you either are not running the latest build or something is set up incorrectly.
Here's a CS6 project that was created in CC and tested in CS6.
The add shadow catcher from Camera Tracking is simply a way of automating what you have done. Nothing more than that.
The last part of your quesiton does not make sense to me. If you are faking the shadow and you have it tied to a 3D layer and you want to spin the whole thing around that would work but it would look like the camera was rotating around the subject instead of the subject, the 3D text, was spinning. If you had a box on a turn table and you spun the turntable the shadow would not spin, it would change shape. If you put the light source also on the turn table then the box and the shadow would spin but the lighting on the box would change. I'm not sure what you are trying to do.
Thank you Rick, and sorry for taking so long to reply. I reviewed all the switches; it was odd because they all seemed to be the same. In any case it then started working. Maybe my description at the end was a bit cryptic, but I generated the Shadow in a separate Comp, and then tied it to the underlying 3D Text that was spinning in the Main Comp. I got the result I was looking for, and so thank you very much for your help. You are a Font!