Using Collada models from Sketchup Warehouse

Using Collada models from Sketchup Warehouse

Here's some tips for using the DAZ Studio Beta to convert Google's SketchUp Warehouse models into OBJ files to use in Bryce. 


Not all of the models could be converted (only about 1 in 5 or so..) and many of those were either poorly made or poorly textured, and thus un-usable. 

*But*, even with that, there are some really neat models there which I could bring over to Bryce and render. Many of the world's most famous buildings have been made into 3d. and the best thing is that they are free! There are a few problems to be dealt with, but I'll mention those later.

If you are interested in the process:

1.) Download from SketchUp Warehouse the model you are interested in: choose either the zipped Collada file (.dae), or the Google Earth (.kmz) file. In my run-through any of the actual 'SketchUp' (.skp) files are useless, as you need SketchUp Pro (ie. money!) to convert them.
1a.) If you choose the Google Earth (.kmz) file, **rename the file extension to .zip***…. (KMZ is a form of zip, and you should be able to open it with no problem once the extension is changed.)
2.) Open the zip file as you normally would.
3.) Using the latest D/S beta (not sure if the latest regular version can handle it, so I used the beta, which definitely does…) import the .dae file from the opened zip file.
4.) If all is well and good, you should see the model. If you don't, follow these steps:
4a.) On the list of the scene content (usually in the left-hand tab column), find and select the item called "Model".
4b.) On the list to the right-hand side of the screen, look under the "Surfaces" tab for the "Shaders" drop-down. Click on that, then click on the first listed 'mesh'. Then when you are exited from there, click on the "Shaders" drop-down again, scroll down to the last listed mesh, and shift-click on that mesh name. This will highlight all of the included meshes for the next step.
4c.) Just below the "Shaders" box, will be a slider for "Opacity". Slide that all the way to the right (100%) to have the model become visible.

Once it's visible, it is ready for export for Bryce. Choose the File_Export option from the menu, and In the OBJ Export box, make sure that the Convert Maps (for Bryce) is checked. Name your model, and you're good to go.

Now for the caveats:

While most of the models are low-poly, and don't take a lot of memory, there are a few that are HUGE! (Pity, because some look *beautiful* There is a reproduction of the Baths of Caracalla which is superb in it's preview, but I couldn't convert it.). Some of the models should only be used as background filler, as the lack of close-up detail may be noticeable.

To make up for the lack of modeled detail, the system relies heavily on photographic detail on the texturing. As a result, there are sometimes baked-in shadows, and things like people and cars that are captured when the person took the photo of the building. Again, you may have to choose which side of the building to render.

SketchUp/Google Earth for some reason uses white as it's transparency color, so some items (for example, a propeller blade) which is modeled as a simple square with a picture attached) will render out the whole image; prop blades on a white square. You may have to do a bit of trans-map work.

Lastly, because of the system, most of the model makers call their model "Model.dae" and all of their textures something like "Image1.jpg" and Image2.jpg"…. Thus, trying to use more than one of the models in a scene becomes a nightmare, with cross-references getting all messy.

But, if you can maneuver around these pitfalls, there are some gems to use. I have gotten about 100 building models converted to a fairly acceptable stage. Some will need tweaking, but most render quite well as middle to long distance elements.

And the reason I started rummaging around in SketchUp Warehouse: Bryce 7 beta 'lists' the Collada .dae file format in the import menu… not yet working, but once it is, you won't have to do the DAZ Studio conversion run-around.
 Alcazar Castle
Alcazar Castle

Boston's Trinity Church

Boston's Trinity Church

 Brabant Castle

Brabant Castle

Mont St. Michel

Mont St. Michel

 Schloss Schwetzingen

Schloss Schwetzingen

HDRI/IBL  in Bryce….A New Approach

HDRI/IBL in Bryce….A New Approach

By now, most Bryce users have played with the HDRI/IBL sttings in the Sky Lab.  And we've become accustomed to the need for the "Spherical Probe" type of HDRI image in order for Bryce to play nice.  While there are some of these available on the web, as well as tutorials on how to make them, they remain a curiosity….we seem stuck in the "Shiny Reflective Sphere" stage, just as we first opened Bryce and put that shiny sphere over a plane of water.

But it is time to move on, my friends.

Continuing investigations in HDRI lighting studies, leads me to a startling conclusion: ANY square-aspect image can be used in Bryce's IBL/HDRI input, as long as it is converted to an .hdr file. For purposes of these experiments, I began in Photoshop, made some color gradient images, took those into HDRIshop, converted them *directly* into .hdr, then used them –unaltered in appearance– in Bryce's Sky Lab.

After some investigation, here's what is happening behind the Bryce Sky Lab functions.The square aspect image is 'read' only in a circle that fits into the square…this readable area is then shrink-wrapped over the IBL lighting 'sphere' (an imaginary super-sphere which will surround your scene…essentially it is the 'sky'). The image information from the arced corners is discarded. The outer circumference of the image's circle is pulled down to a point on the opposite side of where the image's center will show. There is considerable stretching of the image, particularly noticeable where the 'backside' of the IBL lighting sphere can be seen.  Shrinkwrap Function 

But if you create an evenly colored square image, no distortions will be noticable. I created a circular red-white gradient …and made it into a .hdr file, and used it to be the only light in a scene. In the scene were a cylinder and a sphere, both colored flat white. I rotated the view to show how the gradient appears in the scene (if used as background) and how the lighting affects the objects.  You can see where the white outer edge of the circular gradient has been pulled together into a small area on the 'backside' of the IBL image sphere.  In these red-white images, NO added lights were used, the sun was turned off, and the HDRI settings in the Sky Lab were:

Quality 256
Intensity 10
HDRI Effect 100

Now, what this does NOT do is cast true shadows.
In the next set of images, for the first, I added a ground plane (colored white) and rendered with only HDRI/IBL; no sun or other lights in the scene.  In the second image, I added a white-colored sun positioned roughly where the light was coming from in the HDRI/IBL image.Take a good look at the cast shadows now…. With normal 'sunlight' in Bryce, those shadows would be shades of black. But here they take on a red cast.

Nest came adding multiple colors in a box-like formation…trying to imitate the ambient light found in an enclosed room with different colored walls. I still need to experiment with how to lay out the blocks of colors, but this gives the idea well enough.You can see where the hdri image is very jaggy where the colors meet, due to the shrink-wrapping and distortion effects,….but just look at the amazing color blends that occur on the objects!!

In conclusion:
What we have with the HDRI/IBL function is a way to create image-based *AMBIENT* lighting. We no longer have to be confined to the single-color ambient choice in the atmospheric settings. Other lights *will* often be needed to create cast shadows (if they are truly desired for the render), but you can come much closer to 'real-life' lighting with your IBL functions.  [In addition, though, you can *add* the single-color ambient light setting in the atmosphere settings to give yet another tint to the overall scene.] 

I hope this experiment will give you the push to make experiments of your own in the Bryce Sky Lab!  HappyBrycing all!