Hello, currently the game object I use for main menu demands a camera far plane value of 2700.0 to be seen fully, it cannot even fit anymore into blenders opengl view window. Is there a max recommended value for a camera far plane value into a game? I do know the near plane shouldn’t be less than 0.100 because it loses too much precision in openGL(then Z conflits happen). The scene with the object itself has only 2500 faces.
I think I need that camera value because there is an asteroid belt together with that object I talked about before, and I need the size of the asteroids which are far from the camera to be the closest to the size one would expect from a very distant object(very small), something only possible with a huge scale, or with coding tricks(greatly reduce size based on distance to camera); which of the two ways you would use for that? Also what should I do for the opengl view window in blender to display fully my object? Is there any performance hit for a scene with huge objects, but low polygons?
This is not a good idea.
You would expand the z-Buffer that much, that your other “Normal”-sized objects would fail the z-Buffer processing (similar to you 0.100 near plane idea).
The best way is to use a background picture.
Methods:
A) skybox/skysphere
B) background scene with synchronized cameras
In terms of rendering the performance depends on:
the amount of faces on screen
the size of the faces on screen
–> = how much pixels a face fills
–> regardless if other faces cover the pixels of the face
–> excluding faces facing away from the camera (~50%)
As the screen is 2 dimensional the depth does not matter. That means a small face near the camera that fills 500 pixels eats the same amount of render resources as a large face far away but fills 500 pixels too.
The same belongs to faces at the border of the screen. If the remaining parts of the face fill 500 pixel it eats the same resources.
(Please note: “fill pixel” means it would draw a pixel, but the pixel might be drawn by other faces [Z-buffer-processing])
Thanks for the answer, I read it all; but a couple more questions:
If the scene had no normal sized objects? Then there would be no problem I think? Is there an average max limit for a camera far plane? How they make then in films or games things far into the space looks correctly far while a part of this same thing(simultaneous a part far and another near) which is near the camera looks enough detailed? Do they use the tricks I mentioned(or you mentioned) or something?
PS:
This main menu background object will not be part of the gameplay, but I do need it to be animated.
If your worry is initially just the Size of the Object, then you could as well just make the whole Thing smaller, like in old Movies a Model Town or Monster would look adequately huge if only the Camera is close enough. (However, renderwise it might end up pretty much the Same, I would guess.)
How they make then in films or games things far into the space looks correctly far while a part of this same thing(simultaneous a part far and another near) which is near the camera looks enough detailed?
I didn’t understand that one Thought, but concerning your Rocks/Astroids, you want those in the Foreground a Bit smaller and those in the Background a Bit bigger, so that the Size Difference is more balanced? Then how about just changing the Camera Lens Factor of your Camera for this Scene?
What exactly is the behavior of camera focal length in blender? It makes objects far from the camera look farther with low values and does the opposite for high values?
PS: I read your post Monster, and I know what you mean by what I studied from OpenGL and for what I experienced(thought I had not read before which high value far planes aren’t good too).
PS2: The camera lens really was a good solution! And I didn’t had to code anything.
