June 10, 2013, 11:27:24 am
It is also interesting that when I render a whole city the render time is 3 secs, but if I get near a single wall to fill the frame, render time increases to 7 secs. Any comments from the staff?
I'll have to check with our dev team on the technicalities of that.
What resolutions are your textures for the walls?
I'm reasonably sure Lumion uses auto mipmaps for it's surfaces, and they are rendered using a range of resolutions, say from 256x256 upwards.
The further away, the smaller the internal mipmaps resolution of the texture, and the quicker it is able to be read from disk, called, and also passed on and off the GPU.
As you get closer, the full high resolution texture will finally get used, and if it's large for example higher than say 4096x4096 then depending on GPU performance there will be more noticeable lag in times as the textures gets read in to GPU memory and used for rendering.
In order to accommodate this texture the GPU may also have to swap other textures in and out of its buffers, costing more time.
If there is also lots of textures needed in the scene and they are all separate images, there is a cost to the GPU as it grabs, orders and swaps the textures for use.