 | | Re: Maximum depth of ldraw models?
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The thread seems to be splitting from the original point, It is a fact that OpenGL generally places a depth of 16 on any transforms. If an LDRAW model in MPD format was presented to OpenGL as a raw data block I suspect that OpenGL would easily hit (...) (18 years ago, 8-Sep-06, to lugnet.cad.dev)
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| | Re: Maximum depth of ldraw models?
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(...) Actually on modern cards strips are always slower than optmized lists. You can always try adding degenerate triangles to stitch strips together to save the cost of multiple render calls (too bad PC cards don't support a primitive reset index). (...) (18 years ago, 8-Sep-06, to lugnet.cad.dev)
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| | Re: Maximum depth of ldraw models?
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(...) Well, typically the multiplies that occur for different studs have the same rotation and scaling aspects, the only thing different is the position. So instead of repeating the multiplication on the original matrix, if the top left 3x3 values (...) (18 years ago, 7-Sep-06, to lugnet.cad.dev)
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| | Re: Maximum depth of ldraw models?
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(...) Okay... 15% speedup is substantial... that means that it's better to pre-transform the subfiles when generating the operations for the current file. I won't worry about the maximum depth any more then. (...) How does a renderer know which (...) (18 years ago, 7-Sep-06, to lugnet.cad.dev)
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| | Re: Maximum depth of ldraw models?
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(...) Same here for LDView. LDView always flattens part geometry, and this seems to improve performance enough to be noticed. LDView does use a display list for each part, and a nested display list for each nesting level above that (as long as you (...) (18 years ago, 7-Sep-06, to lugnet.cad.dev)
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| | Re: Maximum depth of ldraw models?
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(...) MPD files don't add that many extra levels... usually only 2, isn't it? Further, the only stacking that generally needs to occur at the mpd level is modification of the modelview matrix, which opengl guarantees a minimum of 32. It's only in (...) (18 years ago, 7-Sep-06, to lugnet.cad.dev)
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| | Re: Maximum depth of ldraw models?
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(...) I tested the performance of, and saw a decent gain from flattening part geometry. (Perhaps 15% in BrickDraw3D for QuickDraw3D or OpenGL.) What this means is that when a part is prepared into a drawing list, it is not a list of calls to (...) (18 years ago, 7-Sep-06, to lugnet.cad.dev)
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| | Re: Maximum depth of ldraw models?
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(...) As far as building instructions go, LPub only provides for unique background color/backdrop for up to four levels. This is about as much as I've ever seen in LEGO building instructions. The renderers take care of nesting within individual part (...) (18 years ago, 7-Sep-06, to lugnet.cad.dev)
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| | Re: Maximum depth of ldraw models?
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(...) Hmm. I use MPD models a lot, there can be several levels of nesting within a single .mpd file, and I have been known to refer to .mpd files from other .mpd files. I'm not sure how deep my nesting of model files goes, but I'd be a little (...) (18 years ago, 6-Sep-06, to lugnet.cad.dev)
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| | Maximum depth of ldraw models?
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I notice that no maximum depth is given by the standard. How potentially non-compliant would a renderer be if it fails because parts in a model are too deeply nested (a maximum of as little as 16 on some OpenGL implementations). I notice that no (...) (18 years ago, 6-Sep-06, to lugnet.cad.dev)
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| | Re: What does a subpart with color=24 mean?
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(...) Well, one that I have gives a warning message that says it can't handle color 24 and substitutes 16 for such lines. But I wasn't sure if that was correct behaviour. Another one that I've played with quietly accepts such lines, but appears to (...) (18 years ago, 5-Sep-06, to lugnet.cad.dev)
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| | Re: What does a subpart with color=24 mean?
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(...) Actually, that grep doesn't return anything. '^[ \t]*1 24' does return hits from three files, though. Every single place in the library that this is used, it's used in a reference to one of the edge primitives. The edge primitives use color 24 (...) (18 years ago, 5-Sep-06, to lugnet.cad.dev)
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| | Re: What does a subpart with color=24 mean?
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(...) In the case of some kind of direct color, I guess the rendering program is free to do whatever it wants. The simplest action would be to default to black (either LDraw 0, or RGB #000000). I'd be interested to hear what actual rendering (...) (18 years ago, 5-Sep-06, to lugnet.cad.dev)
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| | Re: What does a subpart with color=24 mean?
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Okay... that makes sense. But what if the contrast color for the current file's main color is just an RGB value rather than a color index? What should the subfile's contrast color be set to in that case? Thank you for your help, by the way. >> Mark (...) (18 years ago, 5-Sep-06, to lugnet.cad.dev)
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| | Re: What does a subpart with color=24 mean?
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(...) The contrast color within the subfile would be defined in the normal way - use the main color for the subfile, and look up the contrast color from the color table. The fact that the originating linetype 1 used color code 24 shouldn't matter by (...) (18 years ago, 5-Sep-06, to lugnet.cad.dev)
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| | Re: What does a subpart with color=24 mean?
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(...) Right... but what should the contrast color be defined as within the subfile? The same? >> Mark (18 years ago, 5-Sep-06, to lugnet.cad.dev)
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| | Re: What does a subpart with color=24 mean?
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(...) Not exactly -- just use the current contrast color as the main color for the subfile. Whenever a subfile is rendered, it should already be looking up the local contrast color based on the local main color. Steve (18 years ago, 5-Sep-06, to lugnet.cad.dev)
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| | Re: What does a subpart with color=24 mean?
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(...) Does that mean that it would be appropriate for a renderer to just swap the main and contrast colors when it encounters such a line, or what? I just want know what a renderer is supposed to do. (...) Well, doing grep '^1 24 ' on the parts (...) (18 years ago, 5-Sep-06, to lugnet.cad.dev)
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| | Re: What does a subpart with color=24 mean?
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(...) It will be the constrast color for the constrast color. Which may be the same as the main color -- but it may not. Also, some viewers (like L3Lab) may balk at rendering a file which uses color 24 in a line type 1. Steve (18 years ago, 5-Sep-06, to lugnet.cad.dev)
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| | Re: What does a subpart with color=24 mean?
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(...) OK, I was partly right. There actually is a standard defined for colour extensions, you can view it here (URL) it only applies to colours defined either in ldconfig.ldr, or in the part files or model files themselves. And it is still up to the (...) (18 years ago, 5-Sep-06, to lugnet.cad.dev)
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