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Displacement Help?
Posted: Tue Jun 26, 2012 4:27 pm
by Kwayde
I'm not sure that this is specifically a Blender issue, but since I'm using it I'd thought I'd post here.
Here's my problem. I've used the following black & white texture below as a displacement map with positive and negative scale values, and the results were less than satisfactory. Even with up to 7 or 8 subdivision levels, the results are still unimpressive. It appears as if the displacements were executed in Blender's native renderer.
However when used as a bump map, the texture came out as expected. Doesn't Indigo support micropolygon displacement? In another project where I used Luxrender, my displacement came out very well as it looked like a more realistic & tactile version of the bump map render.
Am I doing something wrong or does Indigo not render displacement textures that well?
Re: Displacement Help?
Posted: Wed Jun 27, 2012 3:31 am
by CTZn
Hi Kwayde
Try increasingly higher subdivision levels to get finer details, and use 25% of the test value to match the bump mapping better.
Indigo used to adapt the displaced meshes density based on the view but this feature was removed when realtime edition was added to Indigo 3.0. It's a severe loss in the field of displacement if you ask me, since plausible polygons-based landscapes are virtually excluded at this point.
Re: Displacement Help?
Posted: Wed Jun 27, 2012 3:42 am
by OnoSendai
Hi CTZn,
To be precise, view-dependent subdivision currently only works for triangles, not quads. I'll try and get this fixed soon!
Re: Displacement Help?
Posted: Wed Jun 27, 2012 3:49 am
by CTZn
Ah, this makes quite a difference to me, I missed that point. Thanks !
Re: Displacement Help?
Posted: Wed Jun 27, 2012 8:51 am
by CTZn
OnoSendai wrote:Hi CTZn,
To be precise, view-dependent subdivision currently only works for triangles, not quads. I'll try and get this fixed soon!
Wich is to say that micro-polygon displacement is available for everyone out of the box but Maya users, because MtI is still using the external OBJ format for meshes.
So Kwayde, use the view-dependent subdivisions option from your exporter to allow a screen based minimum size for the generated triangles. You will need a much higher maximum subdivisions count; the key then is to throttle further subdivisions by the minimal pixel width allowed for triangles.
A starting value of 3.0 (pixels wide) should allow your computer to pass through. There's not much point in generating triangles below a width of 0.5px, and that's an extreme setting already.
Keep in mind that with the view-dependent option, Indigo will keep subdividing triangles, until they hit the maximum subdivision limit OR go below the minimal width. All in all after the right balance is found you will be able to render more geometric details at a lesser cost.
Posted: Wed Jun 27, 2012 6:34 pm
by Kwayde
Hi Ono & CTZn,
Thanks for your input. I think my problem was that I had not enabled View Dependent Subdivision & Subdivision Smoothing. Also, by changing my Subdivision curvature threshold to 0, I was able to achieve the desired result. Still unimpressive in my opinion.

- Displacement Test 1

- Displacement Test 2
But when I enable the texture for both bump & displacement it looks rather interesting!

- Bump & Displacement Test 1

- Bump & Displacement Test 2
Re: Displacement Help?
Posted: Wed Jun 27, 2012 7:49 pm
by galinette
Your material is too white, you will have stronger shading by using lowering diffuse.
I think this is why disp+bump looks interesting : it accentuates (exeedingly) the shading and adds energy loss. But this would be achieved in a more realistic way by using less pure white material
Etienne
Re: Displacement Help?
Posted: Wed Jun 27, 2012 9:01 pm
by Kwayde
galinette wrote:Your material is too white, you will have stronger shading by using lowering diffuse.
I think this is why disp+bump looks interesting : it accentuates (exeedingly) the shading and adds energy loss. But this would be achieved in a more realistic way by using less pure white material
Etienne
Hi Etienne,
Yes I thought the bump made it look better by increasing the contrast & sharpness compared to the displacement render alone. I used your suggestion and added the color map to the displacement render and these were my results.

- Color & Displacement 1

- Color & Displacement 2
Below are the results of the bump, displacement, and the color maps. I reduced the strength of the bump so the contrast wouldn't be too strong.

- Bump, Color, & Displacement 1

- Bump, Color, & Displacement 2
How does it look?
Re: Displacement Help?
Posted: Wed Jun 27, 2012 10:32 pm
by Zom-B
OnoSendai wrote:To be precise, view-dependent subdivision currently only works for triangles, not quads. I'll try and get this fixed soon!
great to hear that, its on the top of my "make-me-happy-list"

Re: Displacement Help?
Posted: Wed Jun 27, 2012 11:18 pm
by OnoSendai
Zom-B wrote:OnoSendai wrote:To be precise, view-dependent subdivision currently only works for triangles, not quads. I'll try and get this fixed soon!
great to hear that, its on the top of my "make-me-happy-list"

Really?
I'm curious to know what else is on the list

Re: Displacement Help?
Posted: Thu Jun 28, 2012 12:21 am
by Zom-B
OnoSendai wrote:Really?
I'm curious to know what else is on the list

Indigos view depended Subdiv with Pixel Treshold and stuff is simply awesome for quality controle with great RAM management.
I Model a lot stuff in low poly and smooth it by doing Subdiv. Keeping stuff low poly let you edit it later way more easy then a High Poly mesh!
Also on my list in my subjective priority order:
-
random seed for Render-Q
- Every speed gain is a even BIGER gain for me since I do a lot of Animations, and that sums up the more frames to render
-
Loseless EXR compression, it sucks to flood your HDD GBs of Data (Think about animations here!)
- Multicore and (way) less RAM killing PostPro AD done
after SuperSampling

- No texture stretching for Subdived Meshes and View deepened artifacts on render borders
- Brush based region Rendering on rendertime to "fix" noisy areas of "finished images" (SSS, Caustics etc.)
- Workflow stuff like invisible Emitters, double sided (emitter) materials
- Shadowcatcher Material for easy HDRI + Backplate viz
Thanks for the interest

Re: Displacement Help?
Posted: Thu Jun 28, 2012 12:35 am
by OnoSendai
Thanks Zom-B.
Can you please sort the list in order of preference/priority?
Re: Displacement Help?
Posted: Thu Jun 28, 2012 1:02 am
by CTZn
I was thinking that it was time to start a bugs & requests thread for that purpose (revive old requests), to Santa Klaus, in anticipation
Your list would be an awesome start Zom-B, furthermore because I'd like to discuss some of your ideas !
- Brush based region Rendering on rendertime to "fix" noisy areas of "finished images" (SSS, Caustics etc.)
I was thinking of a mode (OGL ?) that would trace importance and let the user click on the paths to strenghten. The direct selection of a path would be more explicit than brushing the image and avoid wasting ressources.
- And Finally every speed gain is a even BIGER gain for me since I do a lot of Animations, and that sums up the more frames to render.
Damnit, why not a bias-O-meter ? One single slider that would tweak the key settings at once (depth, rejections).
Re: Displacement Help?
Posted: Thu Jun 28, 2012 2:09 am
by Zom-B
OnoSendai wrote:Can you please sort the list in order of preference/priority?
Edited the post above with personal order of preference, but remember that my top priority is enhancing animation workflow with Indigo, and here I am in the the minority of users that are into animation...
CTZn wrote:I was thinking that it was time to start a bugs & requests thread for that purpose (revive old requests), to Santa Klaus, in anticipation
Your list would be an awesome start Zom-B, furthermore because I'd like to discuss some of your ideas !
- Brush based region Rendering on rendertime to "fix" noisy areas of "finished images" (SSS, Caustics etc.)
I was thinking of a mode (OGL ?) that would trace importance and let the user click on the paths to strenghten. The direct selection of a path would be more explicit than brushing the image and avoid wasting ressources.
- And Finally every speed gain is a even BIGER gain for me since I do a lot of Animations, and that sums up the more frames to render.
Damnit, why not a bias-O-meter ? One single slider that would tweak the key settings at once (depth, rejections).
Yes, there are quite some interesting REQ hiden in the Req & Bug Forum, some are worth to be digged out and talked over again

Re: Displacement Help?
Posted: Thu Jun 28, 2012 3:01 am
by OnoSendai
Zom-B wrote:OnoSendai wrote:To be precise, view-dependent subdivision currently only works for triangles, not quads. I'll try and get this fixed soon!
great to hear that, its on the top of my "make-me-happy-list"

Ok, this is fixed now. I also managed to speed up subdiv and displacement by 2x (in some cases).