Many OGRE samples crash or don't render well (Linux / fglrx)

Problems building or running the engine, queries about how to use features etc.
dirkmitt
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Re: Many OGRE samples crash or don't render well (Linux / fg

Post by dirkmitt »

Also, If I'm using MinGW32 to compile Ogre, it goes without say that I'm doing this on a Windows computer. In fact, this one is a Windows 8.1 laptop.

Because it seems probable that the OpenGL 2 rendering system can't handle the Terrain Sample, I have tried running it using the RenderSystemGL3Plus. When I try that, the attempt crashes the Sample Browser with this message in ogre.log :

Code: Select all

13:35:01: DefaultWorkQueueBase('Root') - PROCESS_RESPONSE_END(thread:2b18): ID=6 success=1 messages=[] channel=2 requestType=1
13:35:01: OGRE EXCEPTION(5:ItemIdentityException): Cannot find a writable location in group Terrain in ResourceGroupManager::createResource at ..\..\OgreMain\src\OgreResourceGroupManager.cpp (line 846)
This error message is similar to the one which was commented on here:

Previous Mention of Resource Group Problem under Windows 8

But the thread which I've just linked to above, does not explain where we should apply their fix, to make it affect the Sample Browser.

Again, any help would be appreciated.

Dirk
dirkmitt
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Joined: Fri Sep 15, 2006 3:40 am
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Re: Many OGRE samples crash or don't render well (Linux / fg

Post by dirkmitt »

I have now worked my way through "Basic Tutorial 3: Terrain" , to see whether my problem persists, if I don't rely on the Terrain Sample.
Unfortunately, I got the project to compile, but then the behavior was exactly as it was before.

Using the RenderSystem_GL , I found that executing my test file at first loaded 3 terrain layers successfully, but then spammed my ogre.log with the 'Validation Error Validation Successful' message.

When I reduced the number of layers in the terrain to 2, that error message stopped, but again nothing rendered. In this case, because I did not define a sky cube, the window remained black, but without any hints of errors in the ogre.log .

I think that what this exercise is telling me, is that under OpenGL 2, the texture coordinates must be handed down by the Vertex Program, and asking my graphics card to recompute those within the Fragment Shader goes against its rules. After all, in the FFP, there was only one texture coord index which the FS could write coordinates to: CameraSpaceReflectionVector.

What the new terrain shader does, is to compute the actual coordinates in the vertex program, but then to pack those into the interpolating registers, so that potentially more coordinate sets can be passed to the FS. But then the FS must unpack those, instead of being able to use the received varyings directly as coordinates.

Also, if I just try to select the RenderSystem_GL3Plus from within the tutorial result, I get "Failed To Create a Separable Program" messages. But that is no surprise.

Dirk
dirkmitt
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Posts: 40
Joined: Fri Sep 15, 2006 3:40 am
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Re: Many OGRE samples crash or don't render well (Linux / fg

Post by dirkmitt »

I've come back to OGRE 1.9 after a moderate leave, to download the latest Mercurial updates, and then to recompile the entire project . That last part seems to have been critical, since doing so seems to have resolved the issue.

Thank you, since the devs must have made some relevant changes as well.

I would say your concept is proven now.

Dirk
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