 | | Re: 3D matrix math question
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(...) Well, I know where the camera is, and I can create vectors from the camera to both end-points of the conditional line, and to both control points. I'm pretty sure that the calculation could be done with just this information. However, I'm not (...) (16 years ago, 14-Dec-08, to lugnet.cad.dev)
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| | Re: 3D matrix math question
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(...) In the case that exhibits the bug, the control points are outside the frustum, but the conditional line itself isn't. So I still need to decide whether or not to draw the conditional line. In this case, it was being drawn at times that it (...) (16 years ago, 14-Dec-08, to lugnet.cad.dev, FTX)
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| | Re: 3D matrix math question
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(...) I think you're right. I'll look into that. It seems like the most straightforward, and since it's just a pre-processing step, it shouldn't affect the performance for anything other than model loading. --Travis (16 years ago, 14-Dec-08, to lugnet.cad.dev, FTX)
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| | Re: 3D matrix math question
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(...) Is there some 'easy' way to determine if the control points are in or out of frustum? Is there any other way to transform points, without considering the frustum (Well, obviously there is at least one, but it's the long way of calculating the (...) (16 years ago, 14-Dec-08, to lugnet.cad.dev)
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| | Running Leocad under linux (Ubuntu 8.10 32-bit)
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For anyone interested, I will hereby share my experiences with Leocad under Linux (Ubuntu 8.10 32-bit) I write this because I stumbled across some issues which might be related to LeoCad itself or just my complete lack of experience. This being said (...) (16 years ago, 14-Dec-08, to lugnet.cad.leocad, FTX)
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| | Re: 3D matrix math question
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(...) OK... I think I understand what I was getting at here. When you introduce perspective then the distance of the conditional point from the line becomes important. Eg. if you have a point that is directly behind its line in a perspective free (...) (16 years ago, 14-Dec-08, to lugnet.cad.dev, FTX)
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| | Re: 3D matrix math question
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(...) Hmmm... Though I can't quite pin it down I have a suspicion that this has something to do with the spatial reduction cause by projection. What projection matrix are you using? Would a simple solution just be to move the conditional points (...) (16 years ago, 14-Dec-08, to lugnet.cad.dev, FTX)
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| | Re: 3D matrix math question
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(...) I am not the best in 3D, but if something outside the view frustum, you do not need to draw that. If you have the special case that only parts of what you should draw are outside the view frustum, I would go to calculate that values for a (...) (16 years ago, 14-Dec-08, to lugnet.cad.dev, FTX)
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| | Re: 3D matrix math question
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(...) Actually, the projected points are all that I am checking, and that's how it's supposed to work. (...) No. The way that conditional lines work is that if the two control points lie on the same side of the conditional line on the screen (in (...) (16 years ago, 14-Dec-08, to lugnet.cad.dev, FTX)
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| | Re: 3D matrix math question
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(...) If I understand correctly you shouldn't be checking on the projection, only on the full 3D transformed points. That means you should check after stage 2.5. You'll need the Z value to work out which side things lie on. Tim (16 years ago, 14-Dec-08, to lugnet.cad.dev, FTX)
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