Final answer:
To render the background opaque or colored and leave the object unstained in computer graphics, techniques like alpha compositing or Z-buffering can be used.
Step-by-step explanation:
In computer graphics, to render the background opaque or colored while leaving the object unstained, you can use several techniques such as alpha compositing or Z-buffering.
Alpha compositing, also known as alpha blending, combines the color of the background with the color of the object based on their respective transparency values.
This allows the background to show through the transparent areas of the object, while making the opaque or colored parts of the background cover the object.
On the other hand, Z-buffering is a technique used in 3D graphics to determine which parts of an object are hidden from view.
By adjusting the Z-depth values of the background and the object, you can create the effect of an opaque or colored background while leaving the object unstained.