Crease / Texturing do they link?


I started with RM as a Hobby. Something to play with while I learned Visual Basic. When I started playing with 3DC I didn’t even know what a vertex was!

When I started it didn’t look like IM was an option. This was early ’98.

The major disadvantage of RM is that it is andquot;opaqueandquot;. You have no access to adjacency information and RM often decides that it needs to rebuild its internal lists for no practical reason. You’ll see this in action when you try to deform an object. Often 80% to 90% of the time spent to create a frame is the andquot;renderandquot;.

I actually should have made the jump earlier, but I got lured in by andquot;Fahrenheitandquot; (The merge of Direct3D and OpenGL). It looked as though I would have an easy transition form RM to an equivalent scene graph in Farenheit. The scene graph actually made it to release candidate but was never released. One day it just disappeared from the Microsoft web site.

I was never part of any mailing lists, but I did read the forums.

So Yes, 6.0 is a jump to DirectX 8 IM. But I’m not sure I will use Direct3DX or not. I want to have the most primitive interface possible so that I am in full control. But I am looking at Direct3DX, and if it makes sense, I will use it.


I have been finding that as I texture my model, the crease info get’s corrupted. Has anyone else noticed this effect? Is it a bug in 5.5?

Anyway, it’s well worth doing the crease operation right at the end of the modelling process as this ensures that when you export to MSTS, you don’t get the flashing wheels or odd faces painted dark problems!!


Thanks guys for the replies! I will continue doing creasing last!


Yes, they are linked. 3DC uses Direct3D Retained Mode (RM) as its graphics API. RM requires that when individual faces are painted that the points that they share with surrounding faces be split. It is kind of a long story, but at the time I wrote it I couldn’t think of a way of preserving the creasing. Actually I am not sure I can even now (at least off hand).

Now for my 6.0 plug: One of the things that I am working on for 6.0 is to replace RM as my renderer. I hope this will result is preservation of materials, and creasing over most operations.

So… in the meantime, Creasing should be your last step. You can still do a quick crease just to see how it will look, but it is probably unwise to spend a lot of time creasing specific edges if you are still in the modeling phase.


They are not linked – creasing just affects the vertex normal vectors (at least it should only affect these)

However, last night I was modifying a loco and noticed that some smoothing I had applied had been lost and this happened several times.

It used to be that if you grouped objects the smoothing was lost, but I’m sure I did nothing to the object this time – (I suspect a small bug)


Let me expand on that. I expect that I will use many Direct3DX functions, no doubt. I am actually using a few right now (mesh simplification). But most of the plans I have involve filling vertex buffers myself. That could change as I get better aquainted with IM.


Richard – so you’re moving it to Direct3DX, I wondered when you’d get rid of RM – the new stuff in DX8 looks quite good.

I hacked around with Patrice’s librarys many years ago, but thought RM was not the way to go and dived straight into IM, but spare time (new baby) and M$ killed those projects.

Were you a member of the vbdirectx mailing list?


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