Moving Objects and Lights


Beautiful animation - like a walkthrough or a flythrough - can often be a challenge. Maintaining the quality of a static image but where the camera is in motion throws up certain obstacles that must be overcome.

Most modern rendering software uses Global Illumination (GI) to efficiently calculate the lighting of a scene. The calculation of this GI involves tracing rays (of light) around a scene and evaluating the strengths and colour changes of these rays as they are bounced or absorbed by the various surfaces in the scene. This is an intensive process, and therefore many renderers use just a sampling of these rays (as opposed to EVERY single one) to approximate the global lighting. This is known as a biased renderer.

For a single, static image, this is relatively easy.

However, when a camera is moving through a space, different parts of the scene come into view whilst others become obscured. If ray calculations are not calculated with this movement in mind, you would see artefacts (blotches/speckles/holes) in the final animation. Not very nice!

To solve this, GI must be pre-calculated for every single frame of the animation. This takes longer, but yields good results.

Now, the next potential challenge with an animation is if objects and lights move within the sequence in addition to the camera. This poses a further challenge to the artist as somehow the scene needs dividing up into areas of static geometry (where approximate GI can be calculated) and dynamic geometry/light (where the GI is actually changing frame-by-frame). The different portions of animation are then combined in an editor such as Adobe Premiere or After Effects using masking and matting techniques.

This is all quite complex and time consuming.

However, recent tests with our own in-house pipeline have proved that we no longer need to break apart animation in this way. We can animate lights and objects - along with the camera - and achieve flicker-free animation with far more freedom than we once could.

As an extreme test, watch the short film test above.

Ultimately, this gives our creatives far more choice and flexibility when story-boarding animation and film work.

If you are interested in talking to our team about animation for your next project, please get in touch by phone or email.

#animation #globalillumination