Google Earth-quality render?

Started by WShawn, April 11, 2011, 03:21:24 PM

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WShawn

Hi:

Total newbie here.  I've used Lightwave for over a decade and Cinema 4D for around a year, and I've just come across Terragen.  I'm trying to determine whether Terragen 2 is suitable for a potential job.  If it is I'll buy it in a heartbeat.

Basically I've been asked to recreate a geological feature in the western US along the lines of what you'd get in Google Earth.  I need to be able to start with a view looking down on the feature and then fly low to the horizon to show the elevation (the animation would start with a flydown from space, which I could create with C4D and After Effects).  This is an educational piece, so photorealism isn't paramount, just Google Earth quality.  I'd be following a tutorial from Archer Designs or something similar to bring the DEM data into Terragen (I just wished that tutorial had used US data sites.)

I've read that Terragen can be very slow to render, but I assume that's with all sorts of raytracing and GI and such enabled.  What would I be looking at with something as simple as what I've described, which is basically displacement maps with texture mapping and such?  It would probably be 30-60 seconds of animation in some flavor of HD.  I'm on a Mac Pro 2 x 3.0 Ghz Quad Core circa 2008.  If Terragen does network renders I can add another single Quad Core Mac Pro.

Any thoughts or suggestions would be appreciated.

Thanks.

Shawn Marshall
Marshall Arts Motion Graphics

Draigr

I can't speak with much authority, but I can say that with your detail specs and as long as you're rendering with a smaller resolution (under HD) you shouldn't have much of an issue. Terragen, with a little bit of work, can achieve photorealism without a big hit on performance. Even I can do it, and I'm one of the newest members here.

You're biggest render time sinks are going to be in hi definition clouds and water. There's a lot of optimising options you can change to get the fastest renders possible.

I haven't done it, but I know Terragen can use real world geographic data, so you're fine there.

Terrain also doesn't take much to render compared to the rest of the scene, and with a bit of work, you can get some really spectacular shots.

For this project, I'd feel safe saying Terragen will save you time, you'll just have to keep in mind that everything's generated procedurally, no need for textures and materials and all those lovely settings. Instead, just plug a few nodes together, fiddle with the sliders and hit render. Terragen does the rest.

Although, you can fiddle with all those lovely materials if you want :).

Oshyan

In the interest of better understanding your needs I have to ask: if you want something that is like what you get from Google Earth, why not use Google Earth? Or were you just using that as a rough point of reference? Google Earth is just going to be better at producing that level of (relatively low) quality at high speed. Terragen could do it, and produce better results too (more photorealistic at least), but the speed would not be as good of course since Google Earth is realtime.

- Oshyan

WShawn

Hi:

Thanks for your replies; I appreciate it.  As I wrote, I'm not too concerned with creating a spectacular, photo-realistic render of this geological formation, just something along the quality of Google Earth.  I won't need uber-realistic clouds or water or vegetation.

To use Google Earth for commercial production you have to buy Google Earth Pro, which is $400.  That's not a big obstacle.  The big obstacle is you have to receive explicit permission from Google to use Google Earth animations for video productions.  Basically you have to tell them how you want to use their maps and they'll tell you 2-4 weeks later how much it will cost.  No thanks.

If I go the Terragen route I have to figure out the best way to animate the camera, given its limitations.  I don't know if that means exporting the Terragen terrain as a Lightwave model and bringing it into C4D or creating a camera animation in C4D and somehow importing that into Terragen.

Thanks again.

Shawn Marshall
Marshall Arts Motion Graphics

Oshyan

Given the Google Earth limitations, seeking alternate approaches makes good sense. What about NASA's World Wind or one of its forks? It can be script controlled for camera motion, and has lots of sources of public domain data. http://en.wikipedia.org/wiki/NASA_World_Wind#Add-ons_and_plugins
I'm not sure of usage restrictions, but it's produced by the US government, I would think it's pretty free to use.

If you do opt to try it in Terragen, I would suggest using a full Earth displacement map, use an Image Map Shader in TG2 with spherical projection and enable displacement to create the base terrain, then setup your scene in C4D to reflect the same scales and coordinates as TG, create your camera path and export. Using spherical mapping and displacement in both should make it easier to match things up and avoid having to import/export the actual terrain data. If you end up needing more detail than a high resolution single displacement map will provide, then you can work on incorporating higher resolution data in the specific areas you need it. Once you get to that point we can direct you to some discussion of how to approach blending in the data effectively, but proving the initial workflow is going to be the biggest hurdle I think (along with render time tests).

Hopefully that gives you a starting point.

- Oshyan

WShawn

Thanks again for the reply.

I have used World Wind in the past for some satellite imagery that was public domain.  It was kind of a kludge for me though, since I basically end up taking a bunch of screen grabs to get the images I need.  I'm not familiar with script controls for cameras.  I also didn't think it could replicate displaced terrain like Google Earth can.

I think the first thing I'll need to figure out is how to get the DEM data and how I would get a satellite image in registration with that data.  I've been sorting through various tutorials and directions mentioned in these forums.  The one from Archer Designs uses the Canadian system, so I can't follow those directions exactly.

Shawn Marshall
Marshall Arts Motion Graphics

RArcher

Google Earth is likely using the available NED-1 data from the USGS for its relief data.  You can obtain and use this same data in TG2 quite easily from http://seamless.usgs.gov

For the satellite coverage you would likely not need any greater resolution than what the LandSat 7 coverage provides.  These images can be downloaded here:  http://glcfapp.glcf.umd.edu:8080/esdi/index.jsp

Getting the images positioned correctly can be tricky but not impossible.  (Jo/Matt - Can we please get the ability to georeference images soon!! Thanks  ;D)

Cyber-Angel

There is a Federal Law in the US (Sorry Don't know which one) that mandates that commercial, civilian satellite imagery can not be made available for sale with a resolution lower than 0.5 meters. If you want to sell imagery below this (Note: The lower the value in meters the higher the resolution) then you have to get a special license.

The civilian imaging satellites are capable of imaging better than 0.5 meter resolution but are required by law to up scale to 0.5 meter resolution before sale of the imagery: imagery of 4.0 meters or better is normally reserved for reconnaissance imagery, though there are civilian birds that have higher resolution then the military ones, but they are as stated required by law to up scale to 0.5 meters.

Regards to you.

Cyber-Angel                           

Oshyan

World Wind can do 3D terrain and already has access to global coverage with both terrain and satellite imagery at a reasonable detail level. To get an image sequence (movie) you could simply use a screen recording application like the free Camstudio, or commercial apps like Fraps or Camtasia.

- Oshyan

WShawn

Hi:

Again, thanks for the replies and info; I really appreciate everyone's input.  I was slammed on another deadline and had to put this on the back burner for a bit.

Oshyan--I'll play with World Wind some more when I get a chance.  I'd rather generate the topography models on my end using some combination of Terragen and Cinema 4D, but if I can't get that to work I'll play with WW.  There have been other projects where the ability to generate accurate topography of an area would have been helpful, so I'd like to learn that skill set some day.

Cyber-Angel--Thanks for the info.

Ryan--I looked at your tutorial on bringing DEM data into Terragen2.  Unfortunately, I have almost no experience with GIS.  I've dabbled, but there are so many sources of data and links that I don't know where to start and what to look for.  If I was doing a location in Canada I'd be set since your tutorial shows exactly what to look for and where.  I've come across 2 or 3 sources of DEM data for the US, and they all look and work differently.  One of the things that's vexed me in the past is getting the DEM data at a decent resolution.  If it takes multiple DEM to show what I want, how do I put it together?  I see you used Global Mapper but, again, newbie here, I don't know what it does, and their website is somewhat opaque to me.

And then how do you make sure the satellite images are in registration with the DEM topo data?  It looks like the Canadian system makes it easy to match those up.  Can you do that with the US data, or do you have to eyeball it?

So many questions.  I'll keep researching.

Thanks once again.

Shawn Marshall
Marshall Arts Motion Graphics


Oshyan

seamless.usgs.gov lets you draw a rectangle around the area for which you want data (among other more precise methods) and will then provide you matched data for any number of "layers" (data types) you choose, including terrain (at various resolutions, including the highest for the US that is available), as well as satellite photo data, land cover, etc. So that's probably your best source for US data.

Global Mapper is one of the best and easiest to use GIS apps around so if you can afford it and will be doing more work like this with GIS data, I'd say it's a worthwhile investment. Get it, it will be able to load virtually any DEM data you get, and can ease the conversion and georeferencing process significantly, depending on the data source. Of course the best is if you just have native GeoTIFF data since TG2 can read and georeference it. Unfortunately image maps are not yet georeferenced so you'd need to line those up manually with the georeffed DEMs if you plan to use photo data on top.

- Oshyan

WShawn

Hi Oshyan:

Thanks again for being patient with my questions.  Here's another one.  How does Global Mapper fit into the workflow of finding data online and getting it into Terragen 2 for rendering?  Does the terrain data from seamless.usgs.gov have to be converted to some particular format to be imported into Terragen 2?

If you're growing weary of these questions and know of an FAQ or beginners guide to this stuff, please point the way.

Shawn

Oshyan

Seamless.usgs usually allows downloading of data in GeoTIFF, which TG2 can read natively. So in that case Global Mapper should not be required. GM would only be necessary where your DEM source data were in a format TG2 could not read natively, or in a case where you wanted to stitch multiple DEMs together into 1 large one to avoid having to deal with them separately in TG2.

- Oshyan