What is going on here?

Started by james adamson, September 01, 2020, 05:40:17 am

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james adamson

Hi all.
I have spent hours trying to solve this and I have got nowhere!
Basically there is an issue with caching populations and thanks to a suggestion from Cyphr I moved my whole scene away from 0,0,0,.
I have done this by adding a transform input on my main masks and shifted my render cam and my pop mask projection camera by the same amount. All looked great as I was assuming the populations would be off. They are not they are spot on in terms of layout and match my previous render in terms of each objects relative positions in the scene. 
What has changed is the position of the ground in relation to the camera. (I have checked the unshifted camera with the shifted one. There is only a move in x. and all the transforms are shifted by the same value so I don't think its the camera thats off) And most importantly my road texturing looks all wrong. I spent an embarrassing amount of time getting that to the state its in and all the good stuff is gone. I have looked at shifting the fractals so the same areas are being applied to the road but no luck and also it looks like the cars have disappeared under the road. All i have done is shift the whole scene by 8000 as thats how wide it is at the start of the shot so as to avoid the source objects from the pops being in my render. There are two images which show what I am rattling on about.
Cheers.
James.

james adamson

Oh. Of course i shifted my population center by same amount. 8000!

james adamson

Oh one more thing. The debris going across the road should be different as the pop map and src object was changed for that element so that difference is as expected.
Ta.

sboerner

You should be able to fix the vertical displacement by tweaking the displacement offset of your surface layer. If it's a heightfield there are shaders you can use to adjust those, too. When shifting the road fractals, be sure to use a transform shader with worldspace enabled.

You can have displacement issues when you shift a scene too far from world origin. 8 km sounds like a lot, and may be the cause of some of the differences you're seeing.

Cool-looking scene so far.

Dune

If you shift all just 100m you may be able to put a house over 0/0/0, covering all 'zero objects'.

james adamson

Cheers for the feedback. Yep thats what it looks like all the displacements are weird whatever settings I try.
This shot has had a hurdle at literally every step.
The reason for the huge shift is the src OBJs are enormous and are resized to .01. I made a conscious decision not to run them all through modo and bake in the size to save time. ;D The result is with the instance cache bug the model then fills the screen when rendered so thats why the huge shift. The scene is 8k at its widest so thats the number I chose. Im gonna try and reduce it now I know about this issue with displacements far from the origin. Thanks for the suggestions. If I have to I will go back bake in the size change and then do like you suggest. Stick a house on top of the offending objects.
This population cache thing really needs fixing.
Cheers.
James.

james adamson

Awesome thanks. 
I Reduced my overall offset to 600m. (500m and the thing was still filling screen!) And it's working. Road looks good again population cache rendering correctly even though I know there are some enormous buildings and stuff lurking just off screen!
Thanks a million.
James.

james adamson

A little update. 
I was being an idiot and could have saved myself some time and pain. I did not realise on the population node you could then go into the actual TGO reader and set the import scale there.
Just done that and indeed I can now make my overall offset only 100m Like was suggested by Dune and Cyphyr.
all part of the process I guess.

sboerner

We've all been there. Sounds like you're making great progress. Looking forward to seeing the completed project.

Dune

Yes, you could make the 'zero object' extremely small, say 0.001, and make the instances 1000x. That way you can put a cardboard box (or any chunk of garbage on the street) over the zero object.

Or work without the cache for a final render.

james adamson

Cheers Dune.
Cache working nicely now, just keep running out of memory after about 300 fms rendering. I knew i should have paid up for the 128 gb and I cant upgrade it. (Bloody Apple!) Anyway that I can work around, hopefully thats the only hurdle now before last test render and then final and then comp.
Its nail biting stuff this Terragen business.

bobbystahr

Quote from: Dune on September 01, 2020, 12:14:23 pmIf you shift all just 100m you may be able to put a house over 0/0/0, covering all 'zero objects'.
I've done that more than once LOL
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist