Photon Map vs Lightmap for animation

[vpii]

Out of curiousity why do you see a pre scan of frames when doing animation using Lightmap setting and when you change it to Photon Map it does not pre cycle thru animation frames before it starts to render? Also I would like to here what most of you prefer for animation between the two. Pros and cons of each.

[jure]

Out of curiousity why do you see a pre scan of frames when doing animation using Lightmap setting and when you change it to Photon Map it does not pre cycle thru animation frames before it starts to render? Also I would like to here what most of you prefer for animation between the two. Pros and cons of each.

Photon map shoots photons from light sources. Light map shoots from camera.

So now imagine camera going from one room to the other. In lightmap mode photons would shoot at the start of the animation and only cover first room. This is why we need to shoot photons along the camera path to cover all the required parts of scene. With photon map the photons will shoot from light and so will cover both rooms.

However there is a catch. If your scene is somewhat complex then it may happen that in photon map mode too little photons will reach your camera. That's why lightmap tends to work better for animations - it will shoot photons exactly where you need them.

Check out this tutorials to get a better idea.
(glossary: light cache = light map, irradiance map = FG)
http://www.spot3d.com/vray/help/150SP1/ ... _imap1.htm
http://www.spot3d.com/vray/help/150SP1/ ... _imap2.htm

lightmap:
pros:
- will always cover screen with enough photons
- rarely produces light leaks
- easy to adjust
cons:
- is not as accurate as photon map
- sometimes photons may not reach very small light sources

photon map:
pros:
- very accurate
- usual looks better than lightmap
- can produce light leaks
cons:
- somewhat complicated to adjust with many light sources (you need to adjust photon number lightsource emmits)
- sometimes it's difficult to get enough photons where you need them