Second Life Forums Archive - • • • Prim Errors

Prana Cale

Registered User

Join date: 8 Aug 2007

Posts: 6

08-26-2007 10:48

Hello

I try to build and I have problems with DISAPPEARING prims. When I change viewpoint they are invisible - changing textures cause this effect or make it disappear... lower prim cover upper prim. Currently it make me angry...

Here how it looks:

- This one is ok

- and 5 desgreee changed viewpoing... BUG

Builds looks ok as long as the are wooden. This bug make it very hard to make something useful... Weird, if i drop new build everything is fine, it takes 2-4minute till they start to crew up...

Day Oh

Registered User

Join date: 3 Feb 2007

Posts: 1,257

08-26-2007 11:07

My best guess is that marble texture is 32-bit/alpha... Prana, if trying different textures makes the problem go away, that is probably it. I think you can fix it by saving the texture to your hard drive, opening it in a paint program, and saving it as an image with 24-bit colors, then re-uploading. Anyone else have suggestions?

_____________________

Al Sonic

Builder Furiend

Join date: 13 Jun 2006

Posts: 162

The infamous alpha glitch.

08-26-2007 11:22

You must be witnessing that funny thing that happens to textures that have an alpha channel, as well as any surfaces of a prim with Transparency settings above 0. The OpenGL rendering can go glitchy and mess up which surface goes on top of which.

The alpha channel is only necessary with textures that can be seen through at certain points, yet I've occasionally seen some textures that clearly have an alpha channel despite not needing one. "Builds look OK as long as they are wooden", which is true because the aforementioned wooden texture has no such channel.

So if you want to fix this, I believe you'll simply have to find/make a marble texture without an alpha channel (by the way, that means having the 3 channels for Red, Green, and Blue, but not the 4th for Alpha). Most such textures really shouldn't have one, yet I've encountered at least one myself that did.

EDIT: Day Oh got it. Like Day said, 24-bit, not 32-bit.

_____________________

If I said a thing ya don't understand, lemme know. I too love it when info is easy to read

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Jesse Barnett

500,000 scoville units

Join date: 21 May 2006

Posts: 4,160

08-26-2007 12:47

A lot of the freebie marble texture packs have items with alpha channels in them. Don't know why they put them in there. Right click the object and hit ctrl/alt/shift T and it will show all the texture info

_____________________

I (who is a she not a he) reserve the right to exercise selective comprehension of the OP's question at anytime.

From: someone

I am still around, just no longer here. See you across the aisle. Hope LL burns in hell for archiving this forum

Chosen Few

Alpha Channel Slave

Join date: 16 Jan 2004

Posts: 7,496

08-26-2007 12:54

Yup, the alpha sorting glitch. See the transparency guide at the top of the texturing forum for more information on it. It happens in every OpenGL application there is, from video games to professional 3D modeling programs. The only reason you don't generally see it in games is because game artists are aware of it and they make sure to build around the problem. As an SL artist, you need to do the same thing. Learn how it works, what causes it, and how to avoid it.

_____________________

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Land now available for rent in Indigo. Low rates. Quiet, low-lag mainland sim with good neighbors. IM me in-world if you're interested.

Welcome to the Second Life Forums Archive

• • • Prim Errors - They disapear

• • • Prim Errors - They disapear
Prana Cale Registered User Join date: 8 Aug 2007 Posts: 6	08-26-2007 10:48 Hello I try to build and I have problems with DISAPPEARING prims. When I change viewpoint they are invisible - changing textures cause this effect or make it disappear... lower prim cover upper prim. Currently it make me angry... Here how it looks: - This one is ok - and 5 desgreee changed viewpoing... BUG Builds looks ok as long as the are wooden. This bug make it very hard to make something useful... Weird, if i drop new build everything is fine, it takes 2-4minute till they start to crew up...
Day Oh Registered User Join date: 3 Feb 2007 Posts: 1,257	08-26-2007 11:07 My best guess is that marble texture is 32-bit/alpha... Prana, if trying different textures makes the problem go away, that is probably it. I think you can fix it by saving the texture to your hard drive, opening it in a paint program, and saving it as an image with 24-bit colors, then re-uploading. Anyone else have suggestions? _____________________
Al Sonic Builder Furiend Join date: 13 Jun 2006 Posts: 162	The infamous alpha glitch. 08-26-2007 11:22 You must be witnessing that funny thing that happens to textures that have an alpha channel, as well as any surfaces of a prim with Transparency settings above 0. The OpenGL rendering can go glitchy and mess up which surface goes on top of which. The alpha channel is only necessary with textures that can be seen through at certain points, yet I've occasionally seen some textures that clearly have an alpha channel despite not needing one. "Builds look OK as long as they are wooden", which is true because the aforementioned wooden texture has no such channel. So if you want to fix this, I believe you'll simply have to find/make a marble texture without an alpha channel (by the way, that means having the 3 channels for Red, Green, and Blue, but not the 4th for Alpha). Most such textures really shouldn't have one, yet I've encountered at least one myself that did. EDIT: Day Oh got it. Like Day said, 24-bit, not 32-bit. _____________________ If I said a thing ya don't understand, lemme know. I too love it when info is easy to read .
Jesse Barnett 500,000 scoville units Join date: 21 May 2006 Posts: 4,160	08-26-2007 12:47 A lot of the freebie marble texture packs have items with alpha channels in them. Don't know why they put them in there. Right click the object and hit ctrl/alt/shift T and it will show all the texture info _____________________ I (who is a she not a he) reserve the right to exercise selective comprehension of the OP's question at anytime. From: someone I am still around, just no longer here. See you across the aisle. Hope LL burns in hell for archiving this forum
Chosen Few Alpha Channel Slave Join date: 16 Jan 2004 Posts: 7,496	08-26-2007 12:54 Yup, the alpha sorting glitch. See the transparency guide at the top of the texturing forum for more information on it. It happens in every OpenGL application there is, from video games to professional 3D modeling programs. The only reason you don't generally see it in games is because game artists are aware of it and they make sure to build around the problem. As an SL artist, you need to do the same thing. Learn how it works, what causes it, and how to avoid it. _____________________ . Land now available for rent in Indigo. Low rates. Quiet, low-lag mainland sim with good neighbors. IM me in-world if you're interested.