Shedding Light On The Shadow Caster
30/Sep/2009 04:14 AM Filed in: Tutorials, Cinema 4D
by Jason Brown, Global Animations
One of the first things you need to know when setting up a scene in Cinema 4D is how to light the scene correctly for Shadows. Typically the more lights you add to a scene means the more variables in determining how to control how those lights affect the object(s) shadows in your scene. Open up the the base project file and we can get started.
(project files)
You will notice that when you preview this comp there are 3 different light sources casting 3 different shadows on the text object. It looks pretty harsh and not very realistic.
click to enlarge
Step 1:
With all three lights selected click on "none" from the shadow option under the general tab.
Step 2: Add a new light to the scene and label it "Shadows"
Step3: Change the shadow type on this light to ShadowMaps (Soft)
Step 4: Position the light where it will cast the desired shadow on the text object in the scene. Just in front and above the text object generally works well.
Step 5: Click on the "Details" tab in the light options menu. Check mark the box labeled "Shadow Caster"
You will notice that the shadow is now much more accurate and controllable however, the walls have a banding line look on them now. This happens when the scene is large.
click to enlarge
Step 6: Click on the "Shadow" tab in the light options menu. You will notice that by default "Absolute Bias" is checked.
For normal sized or small scenes this option may work fine. If you have a larger scene you will need to uncheck this box. Once unchecked it will open up the option for "Bias (Rel).
Relative Bias works on a percentage of how big your scene is and should correctly calculate the shadow map for the scene. Click the percentage up to 2% and the "Sample Radius" up to 5. This should alleviate the banding issues and leave you with a normal shadow that is not affected by any of the other lights in the scene. The best thing about the Shadow Caster option is that it will not cast any visible light onto the scene. It will only cast shadows.
Step 7: By now the everything should look good, but if you need a darker or lighter shadow you can do this 2 different ways.
click to enlarge
1: you can move the shadow caster light object closer or farther away from the object
2: you can increase or decrease the shadow caster light objects intensity ...each of these options has its own benefits and pitfalls.
Tip: Changing the color of the shadow:
You can do this by changing the color of the light in the scene, but it is generally reverse of the color you choose. For example if you choose a yellow color from the palette, the shadow would be blue. The best way to change the color is under the "Shadow" tab. Maxon has included a color option for the shadow.
One of the first things you need to know when setting up a scene in Cinema 4D is how to light the scene correctly for Shadows. Typically the more lights you add to a scene means the more variables in determining how to control how those lights affect the object(s) shadows in your scene. Open up the the base project file and we can get started.
(project files)
You will notice that when you preview this comp there are 3 different light sources casting 3 different shadows on the text object. It looks pretty harsh and not very realistic.
click to enlarge
Step 1:
With all three lights selected click on "none" from the shadow option under the general tab.
Step 2: Add a new light to the scene and label it "Shadows"
Step3: Change the shadow type on this light to ShadowMaps (Soft)
Step 4: Position the light where it will cast the desired shadow on the text object in the scene. Just in front and above the text object generally works well.
Step 5: Click on the "Details" tab in the light options menu. Check mark the box labeled "Shadow Caster"
You will notice that the shadow is now much more accurate and controllable however, the walls have a banding line look on them now. This happens when the scene is large.
click to enlarge
Step 6: Click on the "Shadow" tab in the light options menu. You will notice that by default "Absolute Bias" is checked.
For normal sized or small scenes this option may work fine. If you have a larger scene you will need to uncheck this box. Once unchecked it will open up the option for "Bias (Rel).
Relative Bias works on a percentage of how big your scene is and should correctly calculate the shadow map for the scene. Click the percentage up to 2% and the "Sample Radius" up to 5. This should alleviate the banding issues and leave you with a normal shadow that is not affected by any of the other lights in the scene. The best thing about the Shadow Caster option is that it will not cast any visible light onto the scene. It will only cast shadows.
Step 7: By now the everything should look good, but if you need a darker or lighter shadow you can do this 2 different ways.
click to enlarge
1: you can move the shadow caster light object closer or farther away from the object
2: you can increase or decrease the shadow caster light objects intensity ...each of these options has its own benefits and pitfalls.
Tip: Changing the color of the shadow:
You can do this by changing the color of the light in the scene, but it is generally reverse of the color you choose. For example if you choose a yellow color from the palette, the shadow would be blue. The best way to change the color is under the "Shadow" tab. Maxon has included a color option for the shadow.
|