Rendering issues

Started by AlexelA, April 09, 2010, 04:52:03 AM

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AlexelA

Hi,
I have been rendering an image sequence with an animated sunrise in it.
The only setting that changes over time is the elevation of the sunlight.
Now the rendered image sequence shows a different shadow position to that of the 3D preview.
I have done a similar animation before and there was no discrepancy between rendered and previewed images, the shadow movement matched perfectly but now the rendered images are running way behind to those of the 3D preview.The top image is the 3D preview and the the bottom one is the final render, both are on the same frame.

Alex
 

Tangled-Universe

These differences can be annoying indeed, as you're experiencing now.

The 3D-preview is a very crudely optimized "render" of the scene, see it as an approximation.
This also means that things aren't calculated as accurately as in the final render, for speed reasons, and results in discrepancies between the preview and final render.

The fact that you haven't experienced it with an other scene is probably because you used different lighting conditions etc. etc.

In general I've never had 1:1 results with the 3D preview. It is very useful for examining POV's and setting up the rough terrain.
For lighting I'd suggest to *always* test it with test-renders, rather than using the preview. It always differs quite some in my experience, especially the saturation of colours (due to lighting).

Cheers,
Martin

AlexelA

Hi,
thanks for the reply.
I have got a total of 205 frames and in the last 5 there happens most of the action, means the space in front of the camera gets finally completely lit by the rising sun but that's perhaps due to the nature of a sunrise that it's getting faster towards the zenith!?

How is your experience with the 3D preview and a camera animation. Is it very approximate as well, do you do test renders beforehand or do you think one can rely on the play function in the bottom toolbar. Also, is there a way to tweak a camera path (the orange line) other than changing the settings of the keyframes, like in Maya for example?

regards
Alex   

Tangled-Universe

Quote from: AlexelA on April 09, 2010, 11:30:40 AM
How is your experience with the 3D preview and a camera animation. Is it very approximate as well, do you do test renders beforehand or do you think one can rely on the play function in the bottom toolbar. Also, is there a way to tweak a camera path (the orange line) other than changing the settings of the keyframes, like in Maya for example?

I'd certainly never rely on the preview-render alone. I'd always make test-renders.
As far as I know you can only tweak camera-paths by adjusting keyframes.
I'm trying to find out if it is possibly to export low res geometry from TG2 to, say, Blender and animate the camera-path there.

Oshyan

This may have something to do with off-camera terrain not being rendered in the 3D preview, or being rendered with less fidelity. I'm not sure if the "Ray detail region" function in the Renderer node settings affects the 3D preview - my guess would be no. So if you're using that, it might explain the discrepancy. If not, it still may be related to this issue.

Camera paths can only be edited via keyframes at this point. As we finalize the Animation Module additional control will be added (e.g. timeline curve editor).

- Oshyan

AlexelA

Hi,

I have lowered the detail and anti-alias settings in the quality settings pane (Renderers),
thus getting a low-res preview of a 110 frame sequence in less than 12 minutes, that allowed me to judge the camera position relative to the environment no bother.
It's so hard to get a smooth camera movement in terms of speed.
I am looking forward to see what you'll come up with regarding animation upgrade.
Thanks again

Alex