OpenGL-problems

[KeesW]

Here is a strange happening. We're generating an axonometric of a large house. Works fine with the internal engine but with OpenGL, a couple of the roof slabs are missing and so is a portion of the floor. Is this likely to be an OpenGL bug, or a video card problem?

Also, a chap in our drawing office uses Revit. This has apparently been otimised for OpenGL and he says that it shows shadows. I was told that OpenGL has limitations and one of them is that it won't show shadows. Is that right? Or is this a (poor) Graphisoft implementation of OpenGL?

OpenGL default images are very dark. Is that normal?

Cornelis (Kees) Wegman
AC10, Windows XP Pro, 1GB RAM, NVidea FX 5200, 40GB HD (lots of space left on it)

[Dwight]

To test the OpenGL performance of your card, make the OpenGL view smaller.

As for the image being dark, the brightness of the scene is related to the light present in the scene - turn up your sun and ambient lights.

[Dwight]

Ooops.

As for shadows -

Yes, OpenGL can do transparency, shadows - the works.

And so it goes.

[Link]

KeesW wrote:
Works fine with the internal engine but with OpenGL, a couple of the roof slabs are missing and so is a portion of the floor. Is this likely to be an OpenGL bug, or a video card problem?

You may want to check your OpenGL options available from the 3D Windows Settings dialog. Maybe you have a transparent material applied to your roofs & slabs (unlikely), or parts of your model are being culled or incorrectly checked for occlusion(more likely). Not all OpenGL cards support Occlusion checking.

For more information, check p.105 of the ArchiCAD 10 New Features Guide, from your Help menu.

Or it could be an OpenGL bug, or a video card problem!

Dwight wrote:
Yes, OpenGL can do transparency, shadows - the works.

Shadows hey? You sure mate?

Cheers,
Link.

[Dwight]

Well, not in ArchiCAD, but the code allows for it.

And also transparency that we don't have in ArchiCAD.

SketchUp is a prime example of OpenGL shadow casting.

And here, for example, is one of many articles on the topic:

http://www.opengl.org/resources/code/samples/mjktips/rts/index.html

[Link]

Dwight wrote:
Well, not in ArchiCAD, but the code allows for it.

Graphisoft musn't have been willing to pay for that extra functionality!

Cheers,
Link.

[Dwight]

Shadow casting might be tricky, but lots of applications can implement transparency - and not just the on/off invisibility that we have.

OpenGL, with textures, transparency and shadow casting could supplant many of the occasions where we make a photo rendering - in seconds per frame.

[__archiben]

Dwight wrote:
Shadow casting might be tricky, but lots of applications can implement transparency - and not just the on/off invisibility that we have.

it's a really poor show that software as expensive as archicad is cannot implement openGL with the same degree of success as many smaller, cheaper applications can.

i had no idea openGL transparency could be anything other than on or off until i saw the great work pavol had made of it's implementation in 'archishock' . . . when someone can write an add-on for archicad that takes the archicad material data and turns out a far superior openGL implementation you have to wonder just how low graphisoft's internal standards might be don't you?!

~/archiben

[KeesW]

Thanks for your comments. So OpenGL will do shadows? Disappointing to find Graphisoft implement yet another slightly underdone application. AC is not a cut-price product - at least not for the purchaser.

I am becoming weary of having to constantly apologize for unnecessary shortcomings of Archicad - especially when talking to Revit users. They undoubtedly have other problems but at least their important add-ons appear to be complete. How about a patch from GS to bring our OpenGL upto scratch?

Kees

[Anonymous]

Do you want to know what the Mac can do with the right OpenGL code?

http://www.ati.com/developer/demos/macss2/index.html

Imagine if our archicad models could implement some of these features, at least go past the flat shading we currently look at, then shadows, then...