Lightmapping taking way too long

I'm baking the lightmap for a scene with one car and just one other object which is essentially five small cubes combined on one plane, lightend by one directional light. To bake this lightmap, unity takes about 12 hours on my otherwise rather fast computer - I don't think that's normal. Most of the time is spent with "7/11 Light Transport". There are no errors or anything similar in the console. What could be wrong? What can I do to speed up the bake process?

 

I'd be guessing that your Realtime/Indirect resolution is too high.
Could you please post screenshot of your Lighting settings? Also are your objects using 1 unit to 1 meter scale?

 

Thanks for your response. I'm not quite sure which scale I have; I heritaged my objects from someone else and unfortunately I'm not yet that experienced to tell - how can I find out?

In the appendix I send you my lightning settings.

 

Select the object and check it's Scale on the Transform component.
Or you can just create a new Cube near it check if it's similar size, cube's initial scale is 1x1x1, or 1 cubic meter.

In any case try lowering Realtime resolution in Precomputer Realtime GI to something like 0.001. I'm guessing that your objects are huge and thus take so long to bake.

 

Hi, so scale of the objects affect bake time? What actually causes the slow up?

 

Yes, bigger scene (or bigger resolution) results in more clusters, which all have to be handled



Compare how much more detailed GI has to be in this case if I increase resolution 10 times for same scene. With bigger size of scene you simply add additional content, for which GI data has to be calculated.

 

thank you so much man ! You saved my pc from explosion