Indigo Renderer Forum

Ok, don't know if anyone else has encountered this but...

I have not been able to get caustics through water to work for some time, despite following the instructions in this thread. Finally through a lot of trial and error (and a large amount of bad language) I finally discovered that the caustics don't work for me if the underlying texture (pool tiles etc) has a bump applied.

No idea if this is a known bug or just me being stupid about something that's been mentioned before... but anyhow I turned off the bump on my pool walls and hey presto, caustics!

I'm using SketchUp 8 and Indigo 3.4.18

Hi bubs,
I'm aware of the issue.
The problem is is that the uneven surface normals on the pool bottom when you use bump mapping make it a lot harder for MLT. The caustics will still appear, that will just take a lot longer.

Interesting - I have a small bump map applied to my blue pool tiles in the images already posted and the caustics show up pretty much straight away.

The problem I'm having is that for no obvious reason I can't see the caustics when looking into the pool from above anymore. Need to recreate my steps and see where I introduced the issue I suppose.

I've also been trying to model a half and half view showing the outside surface and the caustics underwater, but I can't figure a way to do it. I thought I might be able to just position the camera half and half and then adjust the water volume so that it sits in front of the camera but of course, the water material on the side facing the camera just distorts everything. So I tried taking that entire plane out which gives you the sharp edge, but the water is no longer a closed volume so caustics no longer work. Tried putting a thin glass plane in front instead and still distorts.

Remind me, is there a way to tag a texture or a geometry plane so that it renders (or rather doesn't render) invisible in Indigo? SO I can close the water volume but remove the side that distorts the view....or is that a dumb question!

Bosseye:
Rendering caustics when seen from above the pool is fundamentally a much harder problem for unbiased renderers than rendering caustics from inside the pool. This is because it becomes an SDS (specular diffuse specular) problem, which is hard for unbiased renderers. This is why MLT bidir works best for this kind of scene.

There are a lot of good tips in respect to caustics in CoolColJ's test pic thread:

http://www.indigorenderer.com/forum/vie ... &start=615

i wish i could of understand more on Upgrading my renderings, sometimes it takes alot of time to just render one scene.. and i have a pretty beastly machine working on.
if im not mistaken i read somewhere inside the link you posted that nmcr rate is directly improving wait time during the rendering... i had no idea of the vast depth of rendering techniques i wish to know more...

Hey~ I tried a little with your way, but it seems have huge problem with the water surface. and no matter what I do, the water still has no color, I like the color of your water, how did you do that~

Bosseye wrote:Aha! but if I leave view dependant on, leave subdivision smoothing off and set curvature threshold to 0 instead of 0.1 it works...

Thanks for your help

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EDIT: Wahey! I Like this. It has absolutely no practical application for anything that I use Indigo for, I'll never have a need to render underwater caustics, but its still very clever indeed.

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Hi, to change the colour of the water I simply changed the material colour in Sketchup using the colour wheel so it has a slight blue/green tint to it. Job done

Not sure why you're getting the 'oily' colours effect on your surface though. Perhaps its the tracing method you're using? I used BiDirMLT for all mine.

Hi All,
I made a tutorial on how to make a pool with caustics in SketchUp:

http://www.indigorenderer.com/documenta ... l-sketchup

Please forgive the basic modelling skills

Wonderful!
The displacement shader is excellent, I don't get the whole absorption part though..
It's easier for me to set a little transparency in sketchup and chance the opacity if needed instead of working on the complementary RGB value.

Pibuz wrote:Wonderful!
The displacement shader is excellent, I don't get the whole absorption part though..
It's easier for me to set a little transparency in sketchup and chance the opacity if needed instead of working on the complementary RGB value.

It's a bit hard to visualise. Basically if you want the water to be blue with some green, then you have to absorb lots of red, a little green, and a little less blue.
You get the hang of it after a while

OnoSendai wrote:Hi All,
I made a tutorial on how to make a pool with caustics in SketchUp:

http://www.indigorenderer.com/documenta ... l-sketchup

Please forgive the basic modelling skills

Good tutorial but missing something critical for subdivision:

Make sure the entire water volume object is fully selected by triple-clicking on it:

Should say something like:

Triple click to select the entire water volume object, then make it a group or component. (Edit->Make Group)

Then, double click it to make it the active mesh.

Then, right click and select 'edit active mesh'.

The active mesh is NOT the selected faces, it includes ALL the faces in the current editing context.

Can you change this please?

Yup, will fix.
Edit: Done.

Hi

Well...., after almost 5 year this thread was created, i finally join to the chat
I have to render some images where a pool is involved and i just can not create the caustics...I've tried all methoods suggested here and no luck
This is what i get so far by adding a displacement map to a simple plane group in sketchup ( i do know how the displacement works inside sketchup )

Plese, just tell me caustics are supported by GPU

Have you switched to CPU rendering and did it work there ?