Camera POV and Scale

[sonshine777]

About 1 meter actually.

[gregsandor]

I work almost exclusively with real-world dem data, and for renders where the camera is to be hand-held, I locate the camera around 1.6 or 2 meters above the ground.  Be careful to check proper scale when using objects made by others; sloppy work in scaling will cause no end of trouble.  If your terrain is real and your camera matches the real one, you can modify the objects and goroundcover to fit, not the other way around.  I made a 1 meter cube and a 10 meter cube to check scale.  Guesswork is fine for some but you are on the right track to really getting a controlled image. 

One of the things I have been striving to achieve in creating scenes with TG2, is to set my POV to the same location as my camera would be when I am taking a photograph (1 to 2 meters). This is the point of view I do most of my renders from, which is where my problem begins, at that elevation I can't get the rocks and dirt to look real. I can always raise the camera so it is several meters (10 to 20) above the ground and get the rocks to look ok, but this doesn't work when I am using a real-world DEM for a terrain. Most of the terrains that I use are actual DEM's of real locations, I seldom use the generate terrain feature of TG2. I want my mountains to appear the correct size in comparison to the trees, plants AND ROCKS in the foreground. If I have to raise the camera to make the rocks look good I then have to increase the scale of the trees and plants which in many cases throws the scale of the background mountains and hills.

I see so many amazing images of great rocks that appear to be close up point of views, but I seldom see plants or trees with them. So, my question is, what is the average height of your camera above the ground when you render?

Just thought it was a good question to ask.

If some of these renders have the camera at 1 to 2 meters above the surface I would love to get a .tgd or .tgc to look at and see where I am going wrong.

Thanks

Tom

[Mr_Lamppost]

Even though I work with procedural terrains I always work at 1 to 1 real world scale.  I just find it easier that way, lots of my scenes use functions so scale is important.  I am not that bothered about flying cameras but if objects form an important part of the composition I place the camera 1.7 metres above the ground. I am not a great user of fake stones so can't guide you there.

One of the biggest problems I have found is the scale of imported objects. This varies wildly and can be a real spoiler of scenes, objects are often 10 or 100 times larger or smaller than  they should be; commonly but less frequently off by a scale of 3.  I have found this type of scaling error creeping in during the conversion process.  Build an object in Wings 3D using 1 arbitrary unit as equal to 1 metre, save as .obj and import to Terragen; no problem.  Open the .obj in Blender to apply uv mapping and resave; import to TG and the object is only one tenth the size it should be.  The rescale occurs at the import to Blender stage but as Blender's unit is also arbitrary this is not immediately obvious.  The scale by 0.3 or 3 is probably the result of  an unnoticed conversion from feet to metres.

Rimmer moment (Double salute and emphasis on the RIM*). If I say it's a 6m lighting column you can be sure it is 6m above ground, actual lamp height may vary slightly depending on lantern used.
* Make it sound like a toilet cleaner: RIM-mer. 

To get around this problem I made myself a set of reference grids and check the scale of objects against these before I use them, applying appropriate corrections to scale as required. I posted a download link a couple of weeks ago, the title of the thread was probably not that helpful but it can be found here: 

http://forums.planetside.co.uk/index.php?topic=3766.0

The request for the inclusion of reference human figures has not been forgotten.

[sonshine777]

Thanks Mr_Lamppost for your input, Scaling the models hasn't been the problem per say. I have used you grids and they work great. I used the 10 cm one to scale the butterflies I have posted recently. My problem has been getting the scaling small enough to make the dirt look like dirt and not dirt clods. If you go too small on the scaling you end up with all kind of interesting thing protruding out of the ground, or everything goes black. I intend to keep playing with it, I just started the thread to see if anyone else was doing renders from ground zero so to speak.

[gregsandor]

Thanks Mr_Lamppost for your input, Scaling the models hasn't been the problem per say. I have used you grids and they work great. I used the 10 cm one to scale the butterflies I have posted recently. My problem has been getting the scaling small enough to make the dirt look like dirt and not dirt clods. If you go too small on the scaling you end up with all kind of interesting thing protruding out of the ground, or everything goes black. I intend to keep playing with it, I just started the thread to see if anyone else was doing renders from ground zero so to speak.

To solve the "things protruding too much" problem, make sure you also scale your displacement using real-world measurements.  Displacement multiplier of .01 is a centimeter, which is a pretty tall grain of sand.  If you want small grains of dirt, make sure to tell TG to make them small.  Scale those clods down to .001 and see what happens.

And there are some of us "doing renders from ground zero," with real data.

[Matt]

To solve the "things protruding too much" problem, make sure you also scale your displacement using real-world measurements.  Displacement multiplier of .01 is a centimeter, which is a pretty tall grain of sand.  If you want small grains of dirt, make sure to tell TG to make them small.  Scale those clods down to .001 and see what happens.

Ideally that is what you should do. Unfortunately the Power Fractal starts running into problems with values as small as 0.001, as in this thread:

http://forums.planetside.co.uk/index.php?topic=3883.0

There are probably ways to avoid aftefacts though, if you use a blend shader to fade the fractal to 0 in the distance. You could do this with the Distance Shader.

Otherwise, bring out the Fake Stones Shader and increase its density. You should be able to make very small features with that.

Matt

[sonshine777]

Thanks Matt, I will try playing with it, I never thought of using the distance shader to blend the fractal.