SL projects update week 37 (2): particle capabilities – viewer release imminent

Update: The maintenance release viewer with the particle capabilities is now available – version – release notes and download.

Server and RC Deployments

As always, please refer to the week’s forum deployment thread for news, updates and feedback.

In a change to the usual server-side deployments, the Main channel and all three RC channels have had their deployments and restarts made on Tuesday September 10th. The reason for the single pass was to apply updates server-side relating to recent Vivox service maintenance.

Details of the updates can be found in part 1 of this week’s update.

Server and RC Deployments Week 38

While the final decisions on deployments will not be made until that start of week 38 (week commencing Monday September 16th), it currently appears as if the following are likely to form part of the deployments:

  • The server-side HTTP updates will be promoted to the Main channel
  • A small server maintenance release will be deployed to at least one RC, which includes a number of crash fixes and an update to parcel access priorities “making it so that avatars who are on the ‘allowed’ list can bypass some of the other access restrictions (payment info on file was listed specifically)”

Particle System Viewer Imminent

Back in week 12, the Lab indicated that the SL particle system would be getting new capabilities, specifically:

  • Glow
  • Ribbon effects
  • Blending options.
Ribbon particle example

The server-side support for these capabilities was duly deployed, but have since been awaiting the viewer-side support in order to be accessible to users.

Commenting on the situation at the Server Beta meeting, Maestro Linden indicated that a release candidate viewer should be appearing with the necessary viewer-side support for the new LSL particle functions and parameters on Friday September 13th.

In preparation for the release, Maestro has also updated the wiki with details of the new particle parameters.

“The new particle glow options are pretty simple,” he said. “If you look at the wiki page, we’ve just added PSYS_PART_START_GLOW and PSYS_PART_END_GLOW, which take a float in the 0.0 to 1.0 range. It basically looks the same as the prim glow setting on prims.”

He went on, “particle blending takes 2 parameters, PSYS_PART_BLEND_FUNC_SOURCE and PSYS_PART_BLEND_FUNC_DEST, and each of those takes one of the 8 ‘values’ listed underneath, so there are actually 8*8 = 64 blend options! You can do crazy things, like having particles invert the thing underneath.

“Anyway, the blend parameters are pretty technical.  It’s basically exposing OpenGL’s glBlendFunc to LSL. And the main  glBlendFunc documentation at goes into the details better than I can.”

For those who can’t wait for the RC viewer with the necessary support to appear, an autobuild version is available.. However, keep in mind this is a test build for the capability, and as such is liable to be behind the curve compared to the RC version in terms of bug fixes, etc., so be sure to update to the RC version when it appears on the wiki page. The RC version is now available.

An example of how the now ribbon capabilities might be used in SL, showing the arc of the sword through the air, supplied by Maestro Linden (courtesy of

The new ribbon capability should allow for much better particle effects for things like ropes and chains links between objects (amount other things), using a ” go-from” prim/position (the prim centre), and a “go-to” prim/position (defined by PSYS_SRC_TARGET_KEY), the advantage being there would no longer be any gaps in the particle stream. However, there may be times when the ribbon effect may not be facing your camera (so there may be times when you need to reposition your camera in order to see the effect).

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