View Full Version : Backdrop image renders very bad!

Julius Caesar
02-19-2003, 02:29 PM
Hello everybody,
it's me again, and I would like to submit another "big" problem I am having with my LW 7.5. It is always something related to my ancient town, where I (would) use an archeological map as background to position properly the reconstructed buildings...
Here I have posted two picture of the same place on the map, the Capitolium. I have set up LW 7.5 and 5.6 with the same values (third images). Here the problems I have:

1) The backdrop image loads incredibly slow... And when I move around the buildings it takes age to reload...

2) Well, the second issue looks quite evident, isnt'it? Even if I have compressed the two images for clear reasons, I can assure that it does not look very different on my screen...

..and useless to say that this backdrop image is another very important point for my reconstruction. Anybody knows how to fix this problem???

Julius Caesar
02-19-2003, 02:35 PM
..something goes wrong and I have posted twice the same post.... Very sorry....


02-19-2003, 04:55 PM
have you tried converting the backdrop images to another format?

Julius Caesar
02-19-2003, 05:03 PM
yes... I have tried TIFF and TGA files... The final map size is up to 20 Mb (it is a very huge image) and I start having memory trouble...
Thank for the tip


Tom Speed
02-19-2003, 08:50 PM
Hi Julius,

Try lowering the bit depth of the image as it may save some memory and speed up movement.


02-20-2003, 03:42 AM
I think you're out of luck:

Since Modeler now uses openGL to draw the texture, the maximum you can do on the resolution in 1024x1024 Pixels (even though some accelerators support 2K x 2K, lightwave doesn't, which in your situation is a shame).
So, there is no point in your image to be any larger than 1K x 1K.
Before Layout used to draw the image "by hand", and could thus accomodate for large size image maps.
The only workaround i can think of would be to vectorize your image in, say, CorelDraw, and import as an EPS or DXF file.
Also, the image format doesn't have anything to do with the openGL representation, internally it is always 24 bit for the openGL texture.

02-20-2003, 03:43 AM
...but it would be nice to have that functionality back in modeler, and it could probably be done in openGL with the hi-res. Feature request time I guess...

Julius Caesar
02-20-2003, 05:40 AM
thank for your post... While I was reading your post I felt my blood freezing.... So the backdrop feature is gone for now, I think that a backdrop image of 1K is quite useless... details are really poor... Anyway, this is not the first OpenGL Limitation. z-buffer prevents a correct Zoom, this one now...
At the end of this post I would like to ask the following thing: now Lightwave supports OpenGL, but does OpenGL support Lightwave????
May be it's time for a NewtekGL?????

Thank you for your continuous help and support...


02-20-2003, 06:53 AM
Well, the step to openGL had some disadvantages, like no interrupteable redraw in Layout.

One thing you could do, is split up your image in sections, save them each as an image and map them to polygons.

I wouldn't blame newtek for the drawbacks of openGL though, and keeping a featureslike hires backdrops with openGL is tricky to program.

Julius Caesar
02-20-2003, 10:37 AM
Hi Lightwolf,
thank for the tip of the polygons...
In any case I am not blaming Newtek, perhaps is the contrary... I am blaming OpenGL... The proof is that Newtek did a great job with the previous versions of the Backdrop... If OpenGL has limitations, it is not a Newtek fault!!! For this reason I have posted the joke "may be time for a NewtekGL..."...



02-20-2003, 11:28 AM
Julius, instead of losing details in your image, why not chop it into sections and use a little bit at a time? You could place some data into the picture or have some data overlap to allow you to easily align the next section you want to work on. I would just open the image in Photoshop and crop out sections and save as new images (obviously, don't save the original image with a hole in it).

Adrian Lopez
02-20-2003, 05:58 PM
I'd like to speak up in defense of OpenGL. OpenGL, like Direct3D, intentionally places a limit on texture size. The actual limit will depend on the drivers and the hardware, but some limit will always exist.

The problem here is not with OpenGL, but with the way Lightwave uses OpenGL. Nothing in OpenGL prevents Lightwave from stitching together a bunch of textured quads to reproduce the backdrop image at full resolution.

As for the zooming-in problem, I don't understand why OpenGL's z-buffer would cause such a problem, but there's nothing special about OpenGL's z-buffer that would make it inferior in any way.

Julius Caesar
02-22-2003, 06:29 PM
Hi Adrian,
I understand your point, and I am fully aware that developing with OpenGL could be difficult and tricky...
My problem is that now I cannot use two of the cardinal features I was using for my project and I need to find a workaround.. and normally workarounds make slower your work....
Thank to everybody for their posts....