is Irrlicht good for me ? ( CAD-like viewer 2M triangles)

stephaneR · Post by **stephaneR** » Fri Mar 28, 2008 9:18 pm

Hi,

I want to create a CAD-like viewer for displaying ~200 different meshes with a total of 1.5 or 2 millions of triangles (no textures, just material color with smoothing).
Initially I planned to do it in pure OpenGL using VBO in static, but before beginning I'm investigating different engines to simplify my work and not reinventing the wheel.

I've seen that the 1.4 release of irrlicht does not use VBO, but the SVN trunk does.
How stable is the trunk if I have to use it ?

I know nothing about DirectX, in my case will the DirectX driver be better ?

Thanks a lot for your help,

Stephane

hybrid · Post by **hybrid** » Fri Mar 28, 2008 9:41 pm

Well, for now the DX driver would not be better, as it has no VBOs, yet. This will change until the official 1.5 release, though. But from a performance point of view this shouldn't really matter.
With VBOs and simple scenes I have rendered about 1mio tris with decent frame rates on my low-end desktop system. So it should be possible to get some reasonable frame rates also with slightly more complex scenes (meaning more different meshes than I used) by simply using some high-end gfx card (which should be standard for CAD workstations). You could easily try some test scenes by loading them with a slightly modified Irrlicht library: Just change the default VBO state to ALWAYS in CMeshBuffer and use several getMesh() calls to load some mesh examples into view. You can extrapolate the general performance of Irrlicht quite easily this way. Of course the actual FPS can vary, but for a first assessment it should do.

stephaneR · Post by **stephaneR** » Fri Mar 28, 2008 9:56 pm

hi hybrid,

thanks for the answer.
I will try to "play" with Irrlicht to check if i can achieve something correct.
FYI, it should not run only on CAD workstations (most of the users are on laptops with ATI X1400

) and I don't really need some incredible framerates. I just want the viewer to be "usable" (I think something like 20fps should be fine).
Do you suggest me to use 1.4 or the dev version (trunk) ?

Stephane

bitplane · Post by **bitplane** » Fri Mar 28, 2008 10:42 pm

trunk will perform better, specially under OpenGL, though it will be subject to lots more changes before the 1.5 release

stephaneR · Post by **stephaneR** » Sat Mar 29, 2008 1:26 am

ok, i will give a try with the trunk.
any release date planned for 1.5 ?

Thanks,

Stephane

rogerborg · Post by **rogerborg** » Sat Mar 29, 2008 8:49 am

Also, if you're building Irrlicht yourself (as you will be if you're doing an SVN checkout) remember to do a "Release" or "Release - Fast FPU" build rather than the default debug build.

hybrid · Post by **hybrid** » Sat Mar 29, 2008 12:00 pm

No release date planned, but I suppose it will take some more month. I'll first finish the 1.4.1 release (with only some minor enhancements and several bug fixes). For 1.5 we wil have to finish the VBOs for DX, and also add several more things from the trackers. I'd also like to get the texture enhancements done for the 1.5 release.

BlindSide · Post by **BlindSide** » Sat Mar 29, 2008 3:56 pm

texture enhancements

How extensive are these enhancements? Are you planning on doing most of the stuff in the roadmap? I think that adding new texture formats would take too long for this release date (Unless you make them applicable only to rendertargets, with no IImage support.).

hybrid · Post by **hybrid** » Sat Mar 29, 2008 11:16 pm

No, probably no FP textures or multi-part textures (cube or 3d textures). Just the OpenGL memory problem, mipmap LOD, and maybe texture compression. All of them only a few hours of work in the best case.