SGI: Computer Graphics

Hi,

I recently installed Houdini 4.0.4 (Octane SE under Irix 6.5) and had some problems with it: objects disappearing after a model/transform operation (and not to be found again) or still rendering in wireframe despite the “shaded” option being checked.

Has someone ever had issues using that version, or can it be considered a stable and “bug free” release?

Thanks

Did you go through the settings in the display [viewport options] panel? There's a setting that allows interactive shaded viewport manipulation, maybe that'll fix the problem? It's not much, but worth trying I guess, it might indeed be a version that had some bugs.

also does your se does have a tram?

thanks for the tips. No TRAM in my Octane. I've tried all the options but still have the same problem. I'll try again

some display options might just not work without a tram?

Key words: SE without TRAM.

Try get your hands on an EMXI/MXE

I think the TRAM only allows you to have a faster preview of a textured model, which is otherwise possible but VEEERY SLOW.
I noticed lots of inconsistencies when using the different tools of that version (4.0.4). A few of them:
- when I unlock a SOP, it makes my model and the associated geometry disappear, like it never existed.
- when I switch to “shaded” view (the option below the viewer), the model still displays in wireframe, despite having its wireframe color correctly changed to that of the current material. I had that problem with many SOPs.

I just wanted to know if someone has had the same problems with that revision of the software? I reinstalled it and the bugs are still there. The Octane and Irix are correctly setup.

Thanks a lot

What version of IRIX was Houdini 4.0.4 designed for? Do the online docs reveal anything? According to this review , Houdini 4 was compatible with IRIX 6.2 or later, and I've noticed occasional glitches when running very old graphic packages on much newer versions of IRIX. Of course, you can't run IRIX 6.2 on your Octane. Do you have access to Houdini 5.5 or 6, or an Indigo2/Indy running IRIX 6.2?

Houdini 4 dates back to 1999 (the same time Irix 6.5 was released) but was probably optimized for 6.2.
So the combo Octane/Irix 6.5 might be the problem. The software's documentation is silent about any incompatibilities/problems.
I do own an Indigo2 Extreme, but it's not an impact (OpenGL native) machine so running Houdini 4 on it would be horribly slow. Like you said I guess I'll have to buy an Indigo2 Impact (I have the 6.2 install CDs) or else cope with the glitches...

houdini 4 on the octane running 6.5 is fine

It works just fine on an VPro graphics IP35 system, I can tell you.

Express graphics (XS/XZ/Elan/Extreme) are OpenGL native - everything from RealityEngine on had a native OpenGL implementation. It doesn't have hardware texturing, though. The only oddity is Express graphics without Z-buffer, which do not have any sort of Z-buffering support. This would only affect XS (without Z) and homemade Indigo graphics variants that SGI didn't distribute.

A 1999 program should have support for IRIX 6.5 (released June 1998), but would probably run under IRIX 6.2+.

Nope, the first OpenGL implementations were Indigo2 IMPACT, and Onyx InfiniteReality respectively.

The best reference I could find right now:

A 1999 program would not be using IRIS GL, so it shouldn't have the IGLOO performance hit.

I think we're talking at cross purposes - another SGI piece has the following:



The implementations listed as supported starting in IRIX 5.3 don't have an OpenGL implementation that makes full use of the hardware, so some routines that you'd expect the graphcis to do are instead bustled off to the software renderer with the attendant decrease in performance (most notably texturing in VGX, and the OGL implementation doesn't make good use of the Turbo option on GR1).

The middle graphics had full hardware implementations for both OpenGL and IRIS GL, doing what the graphics could do in hardware and using software for unsupported functions (e.g. texturing on Express).

IMPACT/InfiniteReality and later are "OpenGL only", optimized for OpenGL and using the emulation layer (IGLOO, which uses DGL calls) to support the older IRIS GL library rather than having a "native" implementation.

EDIT: SAQ beat me to it!

Perhaps we could define what it means to be OpenGL native ? My understanding was with SAQ on this one. For example, from the old OpenGL FAQ:

I thought Express and RealityEngine supported OpenGL in hardware - as well as IrisGL. The "optimized for OpenGL" part of the Impact line in your quote was a euphemism for removing IrisGL support in the Impact hardware, hence a software translation layer....

I think I figured it out - Jan Jaap is talking hardware and I'm talking software. In that case yes, IMPACT and InfiniteReality are the first "native OpenGL implementations" in that the hardware was designed around OpenGL. I suspect that RealityEngine2 and Express graphics were designed looking forward to OpenGL (not sure about RealityEngine1), and thus they don't have the limitations in hardware that caused VGX/VGXT/GR1.2 to need to do things in software under OpenGL, but they did come out first with an IRIS GL implementation with the OpenGL following. Scratch that - I know that RealityEngine2 was designed looking forward, since it shipped with Onyx and thus was designed around IRIX 5.1 (which introduced OpenGL).

From a software standpoint there were "full OpenGL implementations" prior to IMPACT and InfiniteReality in the sense that there were SGI graphics options that had native (untranslated) OpenGL support up to the capacity of the hardware - i.e. Newport did raster operations in OpenGL on hardware, Express did (with the exception of Indigo options lacking a hardware Z-buffer) geometry, Z-buffering and raster operations on hardware, and RealityEngine did everything (geometry, Z-buffer, raster, texture) in hardware, with the missing parts filled in on the main CPU (similar to how IRIS GL did it). This is similar to IMPACT and CRM - on a number of IMPACT options texturing is done by the main CPU, and CRM does geometry on the CPU, only these graphics do not support the parallel hardware IRIS GL implementation (using IGLOO instead).

EDITED to replace typo (hardware used instead of software)

Yes, I was talking about hardware.

Here's a paper about the design of the RealityEngine by Kurt Akeley of SGI. Even though the original RE was introduced in the IRIX 4.0x days, this paper talks about OpenGL. Then again, I assume they didn't design OpenGL on a Friday afternoon