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 CAD / *44120 (-20)
  Re: 3D matrix math question
 
(...) 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)
 
  Re: 3D matrix math question
 
(...) 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)
 
  Re: 3D matrix math question
 
(...) 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)
 
  Running Leocad under linux (Ubuntu 8.10 32-bit)
 
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)
 
  Re: 3D matrix math question
 
(...) 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)
 
  Re: 3D matrix math question
 
(...) 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)
 
  Re: 3D matrix math question
 
(...) 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)
 
  Re: 3D matrix math question
 
(...) 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)
 
  Re: 3D matrix math question
 
(...) 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)
 
  3D matrix math question
 
(...) I think I need help. I thought I was using gluProject for the conditional calculations, but discovered that I'm not. I multiple the projection matrix by the model-view matrix to get my transformation matrix, then run the points through that to (...) (16 years ago, 14-Dec-08, to lugnet.cad.dev, FTX)
 
  Re: Conditional Ring primitive?
 
(...) OK, I'll go on evaluating cedge interest when you have fixed this issue. (...) Could be workable indeed. Philo (16 years ago, 13-Dec-08, to lugnet.cad)
 
  Re: Colinear Vertices
 
(...) Of course I start counts from zero ;o) (...) OK! My setup seems to work anyway... Philo (16 years ago, 13-Dec-08, to lugnet.cad)
 
  Re: Conditional Ring primitive?
 
(...) Looks like you found another LDView bug ;-). Zoom out and it works fine. It only doesn't work when the control points are clipped by the edge of the window. I'll have to figure out a way to fix that. (...) It's difficult, but by using polling (...) (16 years ago, 13-Dec-08, to lugnet.cad)
 
  Re: Colinear Vertices
 
(...) Hopefully you have primitive substitution set to two (second notch), since 1 provides 8-sided circular primitives. As for separating the stud logo from the primitive substitution, the logo is an implicit part of the substituted stud. It's not (...) (16 years ago, 13-Dec-08, to lugnet.cad)
 
  Re: BlueBrick
 
(...) Hi Michael, I've just released a new version of BlueBrick that fix the problem for the 4.5V and 12V rails. But you will need to upload some unofficial LDraw parts from the LDRAW.org part tracker, especially the new shortcuts created by Philo (...) (16 years ago, 13-Dec-08, to lugnet.cad, FTX)
 
  Re: x210c01 ChromeSilver Drill 4 x 4 x 7
 
(...) When the curvature is the only concern, then yes, but I have to take the screwshape into consideration, the closer I am to the ideal curve, the easier it is to calculate the screwshape and avoid holes in the part. Furthermore when thinking (...) (16 years ago, 13-Dec-08, to lugnet.cad.dat.parts)
 
  Re: Conditional Ring primitive?  [DAT]
 
I made a quick try - and it doesn't work very well, even when it should (between a cylinder and a cone). Example: (URL) (cedge primitive is here included). Cedge seems to behave correctly on the more sloped cone, but not on the other, it appears (...) (16 years ago, 13-Dec-08, to lugnet.cad)
 
  Re: Colinear Vertices
 
(...) I'll need to keep 3 dp in this case. But since it didn't smooth anyway I had no incentive to enlarge the file... (...) OK, we'll see if there is downsides to this. Maybe for very small details? Have a look at some fine mesh parts such as (URL) (...) (16 years ago, 13-Dec-08, to lugnet.cad)
 
  Re: Colinear Vertices
 
(...) Something to try. If it works it would help for several shading issues I have seen. See for example around peghole going through curved surface of (URL) Could you send me the LDraw file used to generate 61069s01a1.png? I'll see how (...) You (...) (16 years ago, 13-Dec-08, to lugnet.cad)
 
  Re: Colinear Vertices
 
(...) triangle has had its surface normal pulled down. So the triangle isn't co-planar with the quad as far as the lighting is concerned. With curve smoothing, all polygons who share a smoothed vertex use a common surface normal for that vertex. But (...) (16 years ago, 13-Dec-08, to lugnet.cad)


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