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Why does changing one little light cause the entire scene to have to be rebaked?

Discussion in 'Global Illumination' started by ArachnidAnimal, Jul 16, 2015.

  1. ArachnidAnimal

    ArachnidAnimal

    Joined:
    Mar 3, 2015
    Posts:
    1,727
    I am trying to be patient with the lightbaking system, but am becoming frustrated with how it operates.
    I have one little baked point light in my scene. Almost no range. No bounce. I have the lowest possible indirect intensity resolution (0.0001), no indirect intensity. I have 50GB of cache files created, but yet slightly changing the position or intensity of the lights causes another 4 hour bake to occur.

    Like I dont understand why the indirect intensity can't be set all the way to zero, or why light ranges cant be respected.

    Could I be doing something wrong, or is this going to be improved?
    Unity 5.1.1
     
  2. Stardog

    Stardog

    Joined:
    Jun 28, 2010
    Posts:
    1,908
    You must be baking a massive terrain or something to get bake times that long. Try switching it to vertex-lit shader and projecting tree shadows some other way, or reducing its Scale In Lightmap or the lower quality Advanced Parameters.

    You can turn a light off but keep it in the scene with the checkbox of the Light component.

    You probably won't see progressive/selective baking until 2016. http://unity3d.com/unity/roadmap/
     
  3. essimoon2

    essimoon2

    Joined:
    Nov 13, 2013
    Posts:
    195
    I do have the same issue. I bake a scene, do some minor change like re-positioning or adding an object or changing the resolution and everything needs to re-bake. I maxed the cache to 100 GB but I feel that it only takes effect if I change some even more subtle things like light color or ambient occlusion settings.
     
  4. j-baeza

    j-baeza

    Joined:
    May 14, 2015
    Posts:
    26
    Same problem for me
     
  5. KEngelstoft

    KEngelstoft

    Unity Technologies

    Joined:
    Aug 13, 2013
    Posts:
    1,366
    Do you have ambient GI set to realtime or baked?
     
  6. essimoon2

    essimoon2

    Joined:
    Nov 13, 2013
    Posts:
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    In my case it's set to baked.
     
  7. SpiriTx

    SpiriTx

    Graphics QA

    Joined:
    Apr 12, 2012
    Posts:
    252
    We've just uncovered that having baked ambient forces some unnecessary steps to be rebaked even if you change a realtime light.

    Changing static geometry will force a full rebake with precompute and moving baked lights will force a rebake, but that's expected.
     
  8. ArachnidAnimal

    ArachnidAnimal

    Joined:
    Mar 3, 2015
    Posts:
    1,727
    In my case, I am not using any ambient GI, or any precomputed real-time GI:

    lighting1.png


    cache.png

    I am using the lowest possible settings, such that the bake looks good.
    I do have a lot of lights (maybe 20 baked point lights). But the lights do not have any bounce intensity, and the ranges dont intersect eachother.
    Maybe I am using too many lights? I am not using terrain or trees, it is just a building floor type of scene.
    Don't get me wrong, when the bake completes the results are very good, and it is worth the wait. But it just seems like it shouldn't be taking so long for the settings, or changing one baked point light position slightly shouldn't be causing an entire re-bake.
    Could i be using too many lights?


    Thanks.
     
  9. j-baeza

    j-baeza

    Joined:
    May 14, 2015
    Posts:
    26
    Any answer about that ? It's realy painfull to rebake all for one object added in one room of an entire flat...