ETM on Mac?


13-10-2008 15:40:43

I started to play around with ETM because the screenshots were so nifty. I incorporated the sample into an xcode project but the app isn't working exactly right. The region I would expect to see terrain is just a mass of grey. Inspecting the console I found something odd. I'm only including the parts I think relevant (I'm a noob so I could be wrong).

GLSL compiled : DeferredShading/material/glsl/psWARNING: 0:27: extension 'GL_ARB_draw_buffers' is not supported

GLSL compiled : DeferredShading/material/glsl/notex_psWARNING: 0:27: extension 'GL_ARB_draw_buffers' is not supported

GLSL compiled : DeferredShading/material/glsl/nm_psWARNING: 0:27: extension 'GL_ARB_draw_buffers' is not supported

GLSL compiled : DeferredShading/material/glsl/nm_notex_psWARNING: 0:27: extension 'GL_ARB_draw_buffers' is not supported

And further down...

WARNING: material ETTerrainMaterial has no supportable Techniques and will be blank. Explanation:
Pass 0: Vertex program ET/Programs/VSLodMorph2 cannot be used - not supported.
Pass 0: Vertex program ET/Programs/VSLodMorph cannot be used - not supported.

I tried the quick Google search on GL_ARB_draw_buffers for mac but it didn't return anything immediately helpful. Any thoughts out there? The app I'm building is nothing more than the ETSample.cpp found in ETM. I'm using etm-2.2. Oh, and Ogre 1.4.8.



13-10-2008 16:03:18

First of, the first section you posted is irrelevant to ETM, those are materials pulled in from the Ogre demo media, they don't affect the ETM demo. The second part, however, states that the splatting techniques which ETM uses are not supported by your graphics card. Quite frankly, I'm not familiar with Macs, so I don't know what they are usually capable of (you do have the Cg plugin included in your plugins.cfg, right?).

You can try and edit the or files in the media/ET directory. Try disabling the lines that read
position.y = position.y + (delta.x * morphFactor);
Other than that, the shader is very simple, and if it doesn't run, you don't have much options left. Might be that Cg does not have a fitting profile for that specific card, in that case, a rewrite of the shader in GLSL might help.


13-10-2008 16:26:33

Thanks for the tip. I've left the code at home and will follow up later this evening. The cfg files were all pulled from another project and I did not think to check them thoroughly.

This might be better suited elsewhere but is there a more complete sample app available? I'll keep on the trial and error for now though, thanks!


13-10-2008 17:22:57

Not for ETM, at least to my knowledge, no. The next major release will include a better demo.


14-10-2008 07:03:38

The important question is: What graphics card do you have?

If you're using a MacBook you might have problems (as they have some gimpy integrated graphics) but my 5 year old PowerBook that has some sort of ATI Mobility Radeon can handle the arbvp1 and arbfp1 profiles.


14-10-2008 14:47:02

I was missing Cg in my plugins. Thanks :) My sample app is now working 100%. Time to start poking around the code to see what I can make it do!

I'm on a first gen MacBook Pro - no gimpy graphics here (relatively speaking anyway).