Category: SL Tech

Maestro Linden used the Server Beta meeting to announce that Simon Linden’s work on adding some LSL support for materials is now available for testing on Aditi.

Regions roller-test102 and roller-test103, both on channel DRTSIM-253, have the server-side scripting support (note the SLurls are for ADITI).

Please note that this is very much a work-in-progress, and the Lab’s own testing is still underway.

The following details can also be found on the Server Beta Meeting wiki page.

Materials can be added to object faces with llSetPrimitiveParams() functions using the following parameters:

• [PRIM_SPECULAR, integer face, string texture, vector repeats, vector offsets, float rotation_in_radians, vector color, integer glossy, integer environment]
• [PRIM_NORMAL, integer face, string texture, vector repeats, vector offsets, float rotation_in_radians]
• [PRIM_ALPHA_MODE, integer face, integer alpha_mode, integer alpha_cutoff]
  • Valid alpha_mode options are PRIM_ALPHA_MODE_NONE, PRIM_ALPHA_MODE_BLEND, PRIM_ALPHA_MODE_MASK, PRIM_ALPHA_MODE_EMISSIVE

Materials can be read with the various llGetPrimitiveParams() functions using the following parameters:

• [PRIM_SPECULAR, integer face] returns [string texture, vector repeats, vector offsets, float rotation_in_radians, vector color, integer glossy, integer environment]
• [PRIM_NORMAL, integer face] returns [string texture, vector repeats, vector offsets, float rotation_in_radians]
• [PRIM_ALPHA_MODE, integer face] returns [integer alpha_mode, integer alpha_cutoff]

Additional Notes

• Behaviour for both getting and setting materials parameters should basically correspond to behaviour with PRIM_TEXTURE
• The color vectors use 0.0-1.0 as the range, as with llSetColor()
• The integer parameters for PRIM_SPECULAR correspond to the same values that you see in the build tool
• Components of a material can be ‘reset’ as follows:
  • PRIM_NORMAL and PRIM_SPECULAR settings are set to default values by setting the texture to NULL_KEY
  • PRIM_ALPHA_MODE settings are set to default values by setting the alpha_mode to PRIM_ALPHA_MODE_BLEND – mask_cutoff is actually reset to 0 unless the alpha mode is PRIM_ALPHA_MODE_MASK
  • When PRIM_NORMAL, PRIM_SPECULAR, and PRIM_ALPHA_MODE settings are all set to default values, the material is deleted from that prim face, and LI may be updated accordingly
• This new scripted capability will only work on the nominated test regions
• ALM must obviously be enabled.

Known Issues

• The version currently on Aditi lacks proper throttling, so there could be performance issues if scripts behave badly. A throttle will be added in due course
• There is a viewer rendering issue, where the face will not be rendered and you’ll see log spam (BUG-6187). This can happen:
  • If the viewer has ALM enabled
  • And a prim face has a material on it
  • And PRIM_ALPHA_MODE is PRIM_ALPHA_MODE_BLEND (this is the default after a material is added)
  • And the diffuse texture does not have an alpha channel (e.g. plywood)

With reference to BUG-6187, Maestro added, “One thing to keep in mind …  is that if your diffuse texture lacks an alpha channel, you’ll also want to set the alpha mode to PRIM_ALPHA_MODE_NONE to avoid the bug, even if you really just want to add a normal map.”

The bug itself doesn’t mean the alpha mode should be set every time a materials map is changed, only when adding a material to a face which previously didn’t have a material. Maestro went on to give some further information on the issue:

What happens when you add a material via the build tool, is that the viewer inspects whether the current diffuse texture has an alpha channel and automatically sets the alpha mode to ALPHA_MODE_NONE if the diffuse texture is opaque, but keeps it at _BLEND if there’s an alpha channel. Unfortunately, the simulator can’t do this, because it doesn’t necessarily have the texture asset and doesn’t have the right libs to process texture assets in that manner. The build tool has some trickery where it always greys out the UI for alpha mode when the texture doesn’t have an alpha channel. Anyway, it’s kind of a hassle, but once PRIM_ALPHA_MODE is set to something ‘friendly’, you should be able to update normal or specular settings without touching it again.

As this is a viewer rendering bug, there is no timescale as to when a fix may appear.

The Lab is particularly interested in seeing how use of these new parameters may affect performance (such as through rapid and repeated changes to maps), and what kinds of rates cause these issues, so that they can more accurately assess the required level of throttling.

Depending upon how further testing goes, what additional changes the Lab needs to make, and what has already been scheduled at the time, these updates might be available on an RC on Agni in a few weeks.

It’s a light start to project news from the lab this week.

Server Deployments Week 22

There are currently no planned deployments for the week.

Materials LSL Functions

There’s still no firm date for when this are liable to surface for testing, but speaking at the Simulator User Group on Tuesday May 27th, Simon Linden indicated the time is getting “closer”. In the meantime he re-iterated the get and set functions currently being worked upon, which remains as per my week 21 report, namely:

Get functions:

• [PRIM_SPECULAR, integer face] returns [string texture, vector repeats, vector offsets, float rotation_in_radians, vector color, integer glossy, integer environment]
• [PRIM_NORMAL, integer face] returns [string texture, vector repeats, vector offsets, float rotation_in_radians]
• [PRIM_ALPHA_MODE, integer face] returns [integer alpha_mode, integer alpha_cutoff]

Set functions:

• [PRIM_SPECULAR, integer face, string texture, vector repeats, vector offsets, float rotation_in_radians, vector color, integer glossy, integer environment]
• [PRIM_NORMAL, integer face, string texture, vector repeats, vector offsets, float rotation_in_radians]
• [PRIM_ALPHA_MODE, integer face, integer alpha_mode, integer alpha_cutoff]”

The same access rules will apply to materials as for diffuse (texture) maps.

Most people may already be aware that llSetTextureAnim() will apply an animation equally across all three maps applied to an object / object face. However, the Lab is not currently looking to add additional parameters to llSetTextureAnim() so that each type of map independently of the others. Offering an explanation as to why this is the case, Simon said:

I’m guessing that would be pretty ugly to implement … or would need some careful design and thought as it couldn’t create new material entries under the hood.  I think that will have to be a follow-on feature … I can imagine it might create some cool effects but it would have to be carefully done not to blow up the materials accounting.

Group Bans

Simon indicated that the remaining back-end server updates for the group ban service may have been deployed on Tuesday May 27th. If so, it is possible that an initial server-side RC deployment of the group ban code might occur in week 23, together with the appearance of the group ban viewer. however this is pure speculation, and depends on how long the Lab want to let the back-end updates run prior to making a visible code deployment. More is likely to be known following the Server Beta meeting later in the week.