That does sound abnormal - and I can't reproduce the problem on my end. Can you attach the .hip you're using?
Thanks.
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Technical Discussion » Bake Texture ROP issue
- dlee
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Technical Discussion » Bake Texture ROP issue
- dlee
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Technical Discussion » Bake Texture ROP issue
- dlee
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Technical Discussion » refractions indirect noise...cut off method.
- dlee
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You're welcome!
jsmack: I believe it is. I'll take care of it - will be fixed in the next daily build.
jsmack: I believe it is. I'll take care of it - will be fixed in the next daily build.
Technical Discussion » refractions indirect noise...cut off method.
- dlee
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Value of 0.1 will give it 90% chance of terminating at each bounce.
Although… right now there's a bug where the cutoff threshold is being ignored entirely under “probability” mode. There seems to be a ticket for it already.
Although… right now there's a bug where the cutoff threshold is being ignored entirely under “probability” mode. There seems to be a ticket for it already.
Technical Discussion » refractions indirect noise...cut off method.
- dlee
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http://www.sidefx.com/docs/houdini/props/mantra [sidefx.com]
“Throughput” basically limits the number of indirect bounces based on estimated amount of contribution to the final image. “probability” is putting it in user's hand.
“Throughput” basically limits the number of indirect bounces based on estimated amount of contribution to the final image. “probability” is putting it in user's hand.
Technical Discussion » Bake Texture ROP issue
- dlee
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Hi. There was an issue with dicing of objects that relied on render camera transform. This is now fixed. Please try the upcoming daily build and let us know if you still see the issue.
Technical Discussion » Portal interior lighting and noise
- dlee
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Yes, mantra is definitely not alone in having hard time with noise when scenes are lit with mostly indirect light sources…
That said there are a couple additional tips I can offer:
1. increase diffuse quality instead adjusting ray variance samples and noise level - if the majority of the noise is coming from diffuse bounce (like the example scene on the original post), you'd want to increase the number of indirect diffuse rays independently of the number of reflection/refraction/sss/direct shadow rays which are not causing noise. You'll find this is particularly helpful for production shots with lots of mixed material types.
2. consider not using portal lights - This really depends on what types of environment map you're using. Currently mantra's portal lights do not importance sample against the assigned environment map, which means that when there are high contrast light sources in the environment map, the render can be noisier compared to regular environment light.
That said there are a couple additional tips I can offer:
1. increase diffuse quality instead adjusting ray variance samples and noise level - if the majority of the noise is coming from diffuse bounce (like the example scene on the original post), you'd want to increase the number of indirect diffuse rays independently of the number of reflection/refraction/sss/direct shadow rays which are not causing noise. You'll find this is particularly helpful for production shots with lots of mixed material types.
2. consider not using portal lights - This really depends on what types of environment map you're using. Currently mantra's portal lights do not importance sample against the assigned environment map, which means that when there are high contrast light sources in the environment map, the render can be noisier compared to regular environment light.
Technical Discussion » Does Houdini have some problems HDRIs ?
- dlee
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matthias_k: Thanks. Those were very helpful.
Rosko Ron: It seems clear that mantra interprets hdr the same way as all the renderers we've tried so far (prman, arnold, cycles, clarisse, cinema4d, whatever's built into Modo…), so there doesn't seem to be an issue here.
My recommendation for you is to ask cg-source directly and find out what kind of tonemaps or post-processing they're applying to the images, and use those to get the desired looks.
Rosko Ron: It seems clear that mantra interprets hdr the same way as all the renderers we've tried so far (prman, arnold, cycles, clarisse, cinema4d, whatever's built into Modo…), so there doesn't seem to be an issue here.
My recommendation for you is to ask cg-source directly and find out what kind of tonemaps or post-processing they're applying to the images, and use those to get the desired looks.
Houdini Indie and Apprentice » Issues with HDRI brightness
- dlee
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As i menteiond on the other thread, this seems like the case of gamma vs tonemapping. The results you're seeing in Lightroom may be misleading because it's always trying to beautify the images and not represent true pixel values (other than the display transform).
Have you tried opening the .hdr files in Photoshop and see if it matches with what you see in Houdini? I suspect that it does.
Have you tried opening the .hdr files in Photoshop and see if it matches with what you see in Houdini? I suspect that it does.
Technical Discussion » Does Houdini have some problems HDRIs ?
- dlee
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It's interpreting the hdr values correctly as far as I can tell. The hdr files themselves don't seem to have any custom primaries either, at least not in the samples. I suspect that the values you're used to seeing is after tonemapping (the preview images on cg-source seem like they're processed).
Mantra (like most production renderers out there) simply apply gamma by default. You can try custom LUT in the viewer or try different OCIO profiles (on final rendered output, of course) until you find the one to your liking.
edit:
I did some comparison renders to show that all renderers including mantra interpret the HDR file the same way.
You mentioned on the other thread (https://www.sidefx.com/forum/topic/43521/) [sidefx.com] that Cinema4d renders it differently - I don't have access to Cinema4d, but it's possible that it's applying some custom look/display transform out of the box.
Mantra (like most production renderers out there) simply apply gamma by default. You can try custom LUT in the viewer or try different OCIO profiles (on final rendered output, of course) until you find the one to your liking.
edit:
I did some comparison renders to show that all renderers including mantra interpret the HDR file the same way.
You mentioned on the other thread (https://www.sidefx.com/forum/topic/43521/) [sidefx.com] that Cinema4d renders it differently - I don't have access to Cinema4d, but it's possible that it's applying some custom look/display transform out of the box.
Edited by dlee - March 19, 2017 12:36:09
Houdini Indie and Apprentice » colour variations between rendererd in simple scene
- dlee
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Technical Discussion » Mantra Transparency issue ...
- dlee
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It is as the posts above said: The reason why you're getting solid alpha is because transparency and opacity are not equivalent.
Transparency is basically refraction, so its affected by ior, roughness, and lighting (this is why you're seeing the environment map in the parts that are transparent, unless you turn off its visibility in refraction).
Opacity treats as if the parts of the object is not there, so it does affect alpha.
The principled shader doesn't have opacity map built-in, but there are a number of ways to get the effect you're looking for (eg using layer mix).
robsdesign: can you elaborate on the issue you're having with transparency maps with the new principled shader?
Transparency is basically refraction, so its affected by ior, roughness, and lighting (this is why you're seeing the environment map in the parts that are transparent, unless you turn off its visibility in refraction).
Opacity treats as if the parts of the object is not there, so it does affect alpha.
The principled shader doesn't have opacity map built-in, but there are a number of ways to get the effect you're looking for (eg using layer mix).
robsdesign: can you elaborate on the issue you're having with transparency maps with the new principled shader?
Houdini Indie and Apprentice » colour variations between rendererd in simple scene
- dlee
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Hmmm seems like environment light is either downsampling hdri incorrectly or picking sampling directions that are slightly off. You can alleviate this issue by increasing “Light Importance Levels” (add it to ROP or envlight from edit parameter interface) but that's just a temporary workaround that may be limited to this particular hdr image.
I'll file a bug.
I'll file a bug.
Technical Discussion » Mantra and automatic generated Normals
- dlee
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The curp angle on display option is not tied to mantra's.
Regarding the error… I'm not sure - I can not reproduce the problem on my end. If error persists across sessions, I recommend wiping away houdini's preference folder and see if the problem goes away. If not, please file a bug with steps to reproduce the problem. Thanks.
Regarding the error… I'm not sure - I can not reproduce the problem on my end. If error persists across sessions, I recommend wiping away houdini's preference folder and see if the problem goes away. If not, please file a bug with steps to reproduce the problem. Thanks.
Houdini Indie and Apprentice » colour variations between rendererd in simple scene
- dlee
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Technical Discussion » Mantra and automatic generated Normals
- dlee
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Hi. You can add “add normals to geometry” and “cusp angle for vertex normals” from mantra ROP's “edit parameter interface” (or, if you don't want to override it globally, you can add them to individual objects).
Houdini Indie and Apprentice » my shadows through glass are black.
- dlee
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Transmission colour (and nested dielectrics features) on the principled shader will not work in “Physically based rendering” mode unless you enable it explicitly on the mantra ROP (rendering->shading->“enable absorption and nested dielectrics”).
It doesn't seem to affect the colour of photon maps however - that might be a bug. I'll file a bug report.
It doesn't seem to affect the colour of photon maps however - that might be a bug. I'll file a bug report.
Houdini Indie and Apprentice » my shadows through glass are black.
- dlee
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If you want to get non-black shadows without using actual caustics (raytraced or photon mapped), you must enable “fake caustics” on the material. You'll find it on “Opacity” tab on both principled shader and classic shader.
Houdini Indie and Apprentice » Lot of noise when using Skin Shader Core?
- dlee
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The noise is likely coming from subsurface scatter. There's “SSS Quality” slider on mantra ROP that you can adjust. The new SSS is pure raytraced solution, so it tends to get noisier with increased scatter distance. If you haven't yet touched the “scattering distance” or “distance multiplier” parameters on the skin shader, I recommend that you adjust them until you reach the desired look, then adjust the quality settings.
Edited by dlee - Feb. 21, 2017 17:40:21
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