World/screen units

[Thomas An._cg]

What does "World" units mean? (in the Light Cache tab).

Is that centimeters ? miles ? what is it ?

Also about "Screen" units. The documentation says that they do not depend on image resolution ... so ... what *do* they depend on ? I see that the samples have variable size depending on Z-depth, but isn't it roughly that a value of 0.1 means 1% of the image ?
(then again, 1% of what ? the height ?, the diagonal ? )

[joe_b]

World/screen units

I believe that the world units refer to whatever your scene's scale units are

[flipside]

World/screen units

Screen units simply divide your image into equally sized portions. I don't know exactly what it stands for, but imagine it like this: 0.1 will divide the image into 10*10 blocks, taking a LC sample in each block. So there will be relatively less samples in far away regions, and more in nearbye regions of the image. Resulting in more detail in the nearbye regions, and less detail in the ones far away. The smaller the screen units number, the more lc samples will be placed.

In world units, far away regions (with far I mean far from the camera) will have equal detail as nearbye regions. In the image this results in smaller looking samples in the far regions, and bigger in the nearbye. This is usefull for animations where you will get closer to regions that are far away at first, so you make sure the sample size is constant trough the scene.

[flipside]

World/screen units

Everything in LC can be easily tested if you set both first and second bounces to LC, and turn of all filters for LC. That way you will easily see the size of the samples.

[Thomas An._cg]

World/screen units

I believe that the world units refer to whatever your scene's scale units are

I see.
So if a model is 10 centimeters then an LC sample size of 0.001 means the scene will be devided every 0.1mm of the scene. (I hope I got it right)

[Thomas An._cg]

World/screen units

0.1 will divide the image into 10*10 blocks, taking a LC sample in each block. So there will be relatively less samples in far away regions, and more in nearbye regions of the image.

Yup, thats is what I figured as well. Thank you !

In world units, far away regions (with far I mean far from the camera) will have equal detail as nearbye regions.

Makes sense