XNA will use right-handed system!

Graphics and GPU Programming Programming

Started by qingrui July 04, 2006 04:39 AM

18 comments, last by qingrui 17 years, 9 months ago

118

Author

July 04, 2006 04:39 AM

Have you seen the shocking news? XNA team said that XNA will use right-handed system! Is this good or bad? I spent years to be used to the left-handed system, and now I should roll back? The good thing is that it will be the same as 3dsmax, maya, etc - No need for hand conversion any more. For your reference: http://letskilldave.com/archive/2006/06/29/XNA-Framework-tidbits_2E002E002E00_.aspx

Pipo DeClown

804

July 04, 2006 04:51 AM

The conversion wouldn't be -that- hard right? Wouldn't a -1 zscale be enough?

Mykre

405

July 04, 2006 04:58 AM

If you read down the comments further the XNA System will be right handed by default, Left handed systems are still supported.

"letskilldave said:
I want to amplify my own statement and Mitch's: the XNA framework is right-handed, _by default_. Left-handed coordinate systems are also supported."

Mykre - Blog Virtual Realm :- XNA News and Resources from Down Under** For those Interested in an Australian XNA User Group Contact me though my site.

joanusdmentia

1,060

July 04, 2006 05:41 AM

Umm, they can't *not* support left-handed systems. It's just a matrix multiply.

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Anonymous

July 04, 2006 05:59 AM

Isn't this the same as OpenGL now also?

jollyjeffers

1,571

July 04, 2006 06:25 AM

Ultimately its not going to make a huge amount of difference - so probably not worth getting to worked up about. Unless you're getting friendly with the maths then the various D3DX (or whatever its replacement is) calls will mask any of the mathematical complexities.

Having said that, it does strike me as an odd change to make. Especially as legacy (and I think also D3D10) are still LH systems. I'd hazard a guess that initially it'll cause more confusion than it'll solve... but we'll just have to wait and see!

Quote:Original post by Anonymous Poster
Isn't this the same as OpenGL now also?

I believe so, but I'd also imagine you can switch to a LH system in OpenGL if you wanted.

Cheers,
Jack

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Jack Hoxley <small>[</small><small> Forum FAQ | Revised FAQ | MVP Profile | Developer Journal ]</small>

Demirug

884

July 04, 2006 06:35 AM

As far as I have seen all D3D10 samples are still LH but as in D3D9 the D3DX lib still contains the RH matrix build function.

I don’t think that XNA will have a separated assembly for the D3DX functions. The MDX 2.0 betas already integrated everything in only one assembly.

sirob

1,181

July 04, 2006 06:36 AM

Is this possibly due to the issue with matrix multiplies in shaders? NTNET recently mentioned it in the question about SetValue vs SetMatrix. Wouldn't this save that transpose? Or does my math just suck? :).

Sirob Yes.» - status: Work-O-Rama.

Demirug

884

July 04, 2006 06:47 AM

AFAIK The transpose is independent of LH/RH. It’s done to allow the shader to use DP4 operations instead of MUL/MAD or the mul4x4 macro. As every vertex shader hardware out there should be able to do a DP4 as singular operation the precession should be better. Additional the DP4 are more independent than the MUL/MAD chain and can better optimized.