Difference between revisions of "LayerData"
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Chaser Zaks (talk | contribs) (Resolved unknown values) |
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==Usage and Notes== | ==Usage and Notes== | ||
LayerData packets transmit terrain, wind, and cloud information using a custom IDCT routine similar to JPEG but with different coefficients. The data in these packets is stored in a proprietary format of 16x16 meter blocks | LayerData packets transmit terrain, wind, and cloud information using a custom IDCT routine similar to JPEG but with different coefficients. The data in these packets is stored in a proprietary format of 16x16 meter blocks. | ||
Type: | Type: | ||
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:[patchgroupSize] - uint8 | :[patchgroupSize] - uint8 | ||
:[ | :[quant_wbits] - uint8 | ||
:[patchHeader] | :[patchHeader] | ||
::[patchSize] - uint8 | ::[patchSize] - uint8 | ||
::[ | ::[dc_offset] - uint32 | ||
::[ | ::[range] - uin16 | ||
::[ | ::[patchIDs] - 10 bit unsigned integer | ||
:[patchData] | :[patchData] | ||
::[zeroCode] - One bit. If 0, the data is zerocoded | ::[zeroCode] - One bit. If 0, the data is zerocoded | ||
Latest revision as of 22:57, 6 October 2019
Message Layout
{
LayerData High Trusted Unencoded
{
LayerID Single
{ Type U8 }
}
{
LayerData Single
{ Data Variable 2 }
}
}
Usage and Notes
LayerData packets transmit terrain, wind, and cloud information using a custom IDCT routine similar to JPEG but with different coefficients. The data in these packets is stored in a proprietary format of 16x16 meter blocks.
Type:
- 76 : LLSurface (terrain)
- 55 : LLWind (wind)
- 56 : LLCloudLayer (Cloud)
Data:
- [patchgroupSize] - uint8
- [quant_wbits] - uint8
- [patchHeader]
- [patchSize] - uint8
- [dc_offset] - uint32
- [range] - uin16
- [patchIDs] - 10 bit unsigned integer
- [patchData]
- [zeroCode] - One bit. If 0, the data is zerocoded
- [hasData] - One bit, If 0, the entire patch is zeros.
- [data] - has a size of (patchSize % 16) + 2
- [data] ... - repeat until patchSize has been read
- [patchHeader] ... - repeat until patchgroupSize has been read
- ...
The data then has to be decompressed, and I have no idea how this data is used.
You may find some use from the psuedocode at LibSecondLife.org