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Volume inside the volume

PostPosted: Fri Apr 28, 2017 2:16 pm
by coilbook
Hi
why both volumes must have same step length in order to look ok. If one of the volumes has a different step length and it is inside that volume it uses the step length of the volume it is inside instead of its own. Both volumes were simulated separately and have separate textures with their own step length. Can this be fixed

Re: Volume inside the volume

PostPosted: Mon May 01, 2017 3:17 pm
by paride4331

Re: Volume inside the volume

PostPosted: Tue May 02, 2017 12:41 am
by haze
Assuming different step lengths for two overlapping volumes:

If inner step lengths are always chosen over the outer step length, then two volumes with non-zero overlapping regions will show boundary artefacts.

Conversely if outer step lengths are always chosen over the inner, then two volumes overlapping with zero and non-zero regions like the ones in your screenshot will show artefacts like you are seeing.

Lastly, if the average of the step length is used, then both cases will have artefacts.

We have experimented with solutions to this in the past, by removing the step length entirely, but at the time it seemed too slow. For now, the best approach would be to set the step length to the same value for both overlapping volumes.

Re: Volume inside the volume

PostPosted: Tue May 02, 2017 1:10 am
by coilbook
haze wrote:Assuming different step lengths for two overlapping volumes:

If inner step lengths are always chosen over the outer step length, then two volumes with non-zero overlapping regions will show boundary artefacts.

Conversely if outer step lengths are always chosen over the inner, then two volumes overlapping with zero and non-zero regions like the ones in your screenshot will show artefacts like you are seeing.

Lastly, if the average of the step length is used, then both cases will have artefacts.

We have experimented with solutions to this in the past, by removing the step length entirely, but at the time it seemed too slow. For now, the best approach would be to set the step length to the same value for both overlapping volumes.



i will send the scene about the boundary showing with two overlaping grids. they both have same step length