PowerVR Insider Forums

PowerVR Insider Forums http://www.imgtec.com/forum/ This is an XML content feed of; PowerVR Insider Forums : Last 10 Posts Copyright (c) 2006-2012 Web Wiz Forums - All Rights Reserved. Thu, 17 May 2012 03:34:45 +0000 Tue, 15 May 2012 17:22:50 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 10.11 30 www.imgtec.com/forum/RSS_topic_feed.asp PowerVR Insider Forums http://www.imgtec.com/forum/forum_images/web_wiz_forums.png http://www.imgtec.com/forum/ OpenGL ES 2.0 Forum : Strange texture coordinates artefacts (iPads) http://www.imgtec.com/forum/forum_posts.asp?TID=2190&PID=6672&title=strange-texture-coordinates-artefacts-ipads#6672 Author: boroda
Subject: Strange texture coordinates artefacts (iPads)
Posted: 15 May 12 at 5:22pm

Hello everyone,

We developing game, with vast landscapes. Landscape size is about 1km x 1km.

The problem we've mentioned recently that we have HUGE artefacts on landscape. It's looking very strange, and I've never seen such artefacts before. Engine is cross-platform, and on PC and Mac everything looks good.

Geometry is landscape.

Coordinates from -330 to 330.

Texture coordinates: from 0 to 1

Issue is the following:

The closer we move to (1, 1) texture coordinates, the more distortion we have during texture_fetch. You can see the effect on the images.

http://dl.dropbox.com/u/3262472/Landscape-Artefacts/Corner_0_0_Normal.PNG

http://dl.dropbox.com/u/3262472/Landscape-Artefacts/Corner_1_1_Distorted.PNG

http://dl.dropbox.com/u/3262472/Landscape-Artefacts/Corner_0_0_Single_Texture_Nearest.PNG

http://dl.dropbox.com/u/3262472/Landscape-Artefacts/Corner_1_1_Single_Texture_Nearest_Distorted.PNG

1) Corner_0_0_Normal.PNG - Image in the corner of the map with texture coords (0, 0) - everything looks good (as it supposed).

2) Corner_1_1_Distorted.PNG - Image of the opposite corner of the map with texture coords (1, 1) - image looks very distorted.

These images: I replaced our shader with simple texture and enabled NEAREST filter.

Results are very strange:

3) Corner_0_0_Single_Texture_Nearest - Image in the corner of the map with texture coords (0, 0) - everything looks good (as it supposed).

4) Corner_1_1_Single_Texture_Nearest_Distorted - Image in the corner of the map with texture coords (1, 1) - everything looks very bad.

Seems about 20% artefact during fetch in texture coordinates.

Shaders below.

PS.

Precision modifiers in shader do not help at all. We've tried to use highp for everything and it doesn't help.

Can anyone help me how to resolve this issue. If you saw such artefacts please write us.

Fragment shader:

https://github.com/dava/dava.framework/blob/development/Tools/ResourceEditor/Data/Shaders/Landscape/tilemask.fsh

Vertex shader:

https://github.com/dava/dava.framework/blob/development/Tools/ResourceEditor/Data/Shaders/Landscape/tilemask.vsh

]]> Tue, 15 May 2012 17:22:50 +0000 http://www.imgtec.com/forum/forum_posts.asp?TID=2190&PID=6672&title=strange-texture-coordinates-artefacts-ipads#6672 OpenGL ES 2.0 Forum : Android kern panic drivers/gpu/pvr/sgx/sgxutils.c http://www.imgtec.com/forum/forum_posts.asp?TID=2188&PID=6670&title=android-kern-panic-drivers-gpu-pvr-sgx-sgxutilsc#6670 Author: ReubenS
Subject: Android kern panic drivers/gpu/pvr/sgx/sgxutils.c
Posted: 14 May 12 at 12:33pm

Hi,

Wondering if anyone suitably familiar with SGX540 driver internals could comment on this bug report?

http://code.google.com/p/android/issues/detail?id=24118#

In a nutshell the Samsung Galaxy Nexus is occasionally rebooting itself in response to a kernel panic caused by a null pointer in SGXCleanupRequest() in drivers/gpu/pvr/sgx/sgxutils.c. This issue has been observed in stock Android ROMs up to and including the current (as of writing) ROM, 4.0.4.

Thanks,

Reuben

]]> Mon, 14 May 2012 12:33:34 +0000 http://www.imgtec.com/forum/forum_posts.asp?TID=2188&PID=6670&title=android-kern-panic-drivers-gpu-pvr-sgx-sgxutilsc#6670 OpenGL ES 2.0 Forum : Android NDK samples native activity blank screen!! http://www.imgtec.com/forum/forum_posts.asp?TID=2178&PID=6669&title=android-ndk-samples-native-activity-blank-screen#6669 Author: Scott
Subject: Android NDK samples native activity blank screen!!
Posted: 14 May 12 at 10:23am

Hi,

This isn't something we've seen. What version of Android is your device running? Also, when you mention samples, is this the SDK examples? If so, is it just a few or do all the PVRShell based examples show the same problem? What version of the SDK are you using?

Cheers,

Scott

Edited by Scott - 14 May 12 at 10:25am]]> Mon, 14 May 2012 10:23:44 +0000 http://www.imgtec.com/forum/forum_posts.asp?TID=2178&PID=6669&title=android-ndk-samples-native-activity-blank-screen#6669 PowerVR SDKs Forum : PVRSHAMAN http://www.imgtec.com/forum/forum_posts.asp?TID=2187&PID=6668&title=pvrshaman#6668 Author: Scott
Subject: PVRSHAMAN
Posted: 14 May 12 at 10:00am

Hi,

Does the crash occur when exporting from Max or when you're playing with PVRShaman? If the crash is when you're exporting from Max, would it be possible for you to send your scene and a screenshot of your export options to devtech@imgtec.com. If the crash is with PVRShaman, could you send your .pod file to the same address with instructions on how to reproduce it.

At the moment there aren't any plans to export a default .pfx but we'll consider it for a future release.

Cheers,

Scott

]]> Mon, 14 May 2012 10:00:48 +0000 http://www.imgtec.com/forum/forum_posts.asp?TID=2187&PID=6668&title=pvrshaman#6668 PowerVR SDKs Forum : Installing SDKPackage_OGLES2 in Xcode http://www.imgtec.com/forum/forum_posts.asp?TID=2175&PID=6667&title=installing-sdkpackage-ogles2-in-xcode#6667 Author: bootstrapper
Subject: Installing SDKPackage_OGLES2 in Xcode
Posted: 11 May 12 at 5:01pm

Hi Arron, thanks for your response.

I've browsed through the training demos and got them running on my iPad with no problems - thanks.

Could you possibly provide a link to the missing introduction document that is normally in the root of the SDK?

I'm trying to work out a sensible workflow and division of responsibilities as I develop my app. Up to now I have been generating VBOs in my C++ code from parametic equations and doing everything programatically.

I'm begining to see that the more I can do using tooling with the likes of Blender and your tools the more efficient I'm going to be, and I guess the more flexible and reusable my code will be too.

I will be using GLSL and will be blending multiple textures and a height map to create nice surface effects - basically im trying to figure out how much of my work I can/should do in blender and/or using your tools and how much is best/must-be done programatically.

I'm also interested in the .pfx format - am i correct in thinking that this is a way of integrating geometry, textures, and associated GLSL shaders together that can be edited and tweaked in a visual editor?

Also, do you know of any tutorials/books which demonstrate a sensible workflow for using Blender -> your tools & SDK -> C++/OpenGLES2.0 & GLSL?

I'm thinking that intro document may help me with a lot of these questions! If not any pointers you can give would be great.

thanks again :)
]]> Fri, 11 May 2012 17:01:13 +0000 http://www.imgtec.com/forum/forum_posts.asp?TID=2175&PID=6667&title=installing-sdkpackage-ogles2-in-xcode#6667 PowerVR SDKs Forum : begginer question where to start ? http://www.imgtec.com/forum/forum_posts.asp?TID=2186&PID=6666&title=begginer-question-where-to-start#6666 Author: umen
Subject: begginer question where to start ?
Posted: 11 May 12 at 2:11pm

Thanks
can i work with the SDK in eclipse c/c++sdt ?
for cross compile ( using mingw as the compiler in windows )
]]> Fri, 11 May 2012 14:11:58 +0000 http://www.imgtec.com/forum/forum_posts.asp?TID=2186&PID=6666&title=begginer-question-where-to-start#6666 PowerVR SDKs Forum : PVRSHAMAN http://www.imgtec.com/forum/forum_posts.asp?TID=2187&PID=6665&title=pvrshaman#6665 Author: dgu
Subject: PVRSHAMAN
Posted: 11 May 12 at 12:46pm

Dear Team

i am working on 3ds max2012 and the great tools PVRSHAMAN.

unfortunatly the export scene crash alot, for instance since this morning , it must be the 20 th times.

I am wondering as well ,if you will generate a defaul pfx from a max scene , that will be great !!!!

thanks alot

david

]]> Fri, 11 May 2012 12:46:06 +0000 http://www.imgtec.com/forum/forum_posts.asp?TID=2187&PID=6665&title=pvrshaman#6665 OpenGL ES 1.x Forum : Linux framebuffers and EGL/GL http://www.imgtec.com/forum/forum_posts.asp?TID=1359&PID=6664&title=linux-framebuffers-and-egl-gl#6664 Author: debonair
Subject: Linux framebuffers and EGL/GL
Posted: 11 May 12 at 7:46am

AFAIK, we call eglGetDisplay((NativeDisplayType)0); when there is only one display. In some mobile phones (such as motorola) used to have multiple displays, so for those devices you can call it with non zero number.

Your device must be having only one display, so when you call it by 1, it fails.

]]> Fri, 11 May 2012 07:46:58 +0000 http://www.imgtec.com/forum/forum_posts.asp?TID=1359&PID=6664&title=linux-framebuffers-and-egl-gl#6664 PowerVR SDKs Forum : begginer question where to start ? http://www.imgtec.com/forum/forum_posts.asp?TID=2186&PID=6663&title=begginer-question-where-to-start#6663 Author: Joe
Subject: begginer question where to start ?
Posted: 10 May 12 at 5:27pm

Our SDK downloads are here: http://www.imgtec.com/powervr/insider/sdkdownloads/index.asp

This package contains the source code for training courses and demos as well as source for our Tools and Shell abstraction layer. It also contains binaries for our utilities, such as our PVRVFrame PC emulation and PVRTexTool texture compression tool.

There is a step-by-step SDK guide in the root directory of our SDK packages that explains how to setup PC emulation and the rest of the SDK for your target platform. On Windows, this is just a case of opening a training course Visual Studio solution, including paths to the OGLES headers and then linking against the PVRVFrame emulator libraries.

Thanks,
Joe

Edited by Joe - 10 May 12 at 5:29pm]]> Thu, 10 May 2012 17:27:37 +0000 http://www.imgtec.com/forum/forum_posts.asp?TID=2186&PID=6663&title=begginer-question-where-to-start#6663 PowerVR SDKs Forum : Newest PVRlib ( "3.23" ), link error http://www.imgtec.com/forum/forum_posts.asp?TID=2163&PID=6662&title=newest-pvrlib-323-link-error#6662 Author: olivierc
Subject: Newest PVRlib ( "3.23" ), link error
Posted: 10 May 12 at 3:29pm

Thanks it seems to work now :). It's not really clear in the documentation ( or my brain is maybe not able to process it :) ).

anyway I did that :

pvrtexture::CPVRTextureHeader sOriginalTextureHeader(pvrtexture::PVRStandard8PixelType.PixelTypeID,

source.getWidth(), // u32Width,

source.getHeight());

]]> Thu, 10 May 2012 15:29:28 +0000 http://www.imgtec.com/forum/forum_posts.asp?TID=2163&PID=6662&title=newest-pvrlib-323-link-error#6662