PaulM3D

Fathom, thank you for answer! Your method is working propertly, of course. Basically, better than mine previous normalizing to only positive on comp stage. I think you're right about mathematical artifact, so I won't to dig it anymore. It's just working fine.

Hello everyone! I need temperature values render pass for some post compositing purposes from Pyro simulation. When I'm rendering it as "temperature" float 32 pass, I'm receiving negative values near the borders of volume. Why does it happening? Attaching picture. I can normalize this somehow after render, but I want to now why it is that way. There is dead end node "Fit Range Unclamped"(picture attached) in default shader(Fireball in this case). I can pass "temperature" parameter through some "fit ranges" or even "Reshape" node. But it doesn't answering the question Why? And I don't think that is the right way. Should say that remapping from shader tab from shades hasn't worked properly for me - even with clamping and fit set for 0 - 1 there was negative values and values bigger than 1. Basically, I need normalized (from 0 to 1) temperature render pass for my simulation. Maybe someone can help my with this? Will be much appreciate. Attaching 2 screenshots. Don't attaching .hip file because there is a simple sphere with Pyro Explosion shelf preset on it. P.S. Don't want to make another post right now, so should ask - is anybody know proper way to make a vectorfield texture from Pyro Sim in Houdini? Right now I'm using Volume Slice, rendering remapped normalized (from 0 to 1) motion vector pass from top orthographic view and compositing it in kind of flipbook, which is converted into volume texture dds next. Maybe there is another way to do it?

Atom, thank you for your reply! I'm using Image Planes, but i need something else then direct lighting AOV. I need light color, without texture. Basically, I need that: direct_diffuse / diffuse_color_noshading = light(what i need). But without dividing operation. It works for all lights sum with simple lambert node, but not for each light. I've created similar post on SideFX forums, there are wider explanation with hip file of what i need.

Hello! Rendering with Mantra PBR, H14. Have got my own shader built in SHOP. Need to obtain light passes for each light source in my scene. For different reasons, dividing diffuse passes by diffuse_noshaded in post comp is not an option. So, inside my shader i've created simple Lambert node and use it bsdf-output for bsdf input of pbrlighting node. Then use all output of pbrlighting and connected it to exportable parameter. But there is an issue - it works fine with "For each light" toggled off, but when i make it ON i receive black empty passes. Could you please help me with this issue? Maybe, there is another simple way to obtain light color passes for each light in one render?

Hi everyone! Have got some issue in illuminance loop(H14 Apprentice). Trying to export Cl(light color) parameter inside Illuminance loop. Doing this to obtain light color render passes for each light. So, seen in some videos - it's working for people but not for me. When I toggle For Each Light check box on, passes I receive is black and empty. Scene in attach. Could you please help me? I think it's basics and simple, but can't understand, what is going wrong. Would be well appreciate. Thanks for your attention. P.s. using visual builder, not a coder for a now. loop_issue.hipnc

Tried to do the same as there , H13, Micropoligon - not working! What am I doing wrong??? Scene included.ill_loop.hipnc

Ok, I've got an idea - can I use 2 different Illuminance loops in 1 shader with light mask specified for each Loop? Will attach a picture with an example. I think I'm doing something wrong, because got such result: one loop working propertly with both of my light sources. Connected to Cf for visual seeing, export working as well. But 2-nd created Illum. loop with another light source is doing the same result as 1-st one. Exactly the same. Can that be done this way? Right now I'm talking not about "For each light" basically, but about type of construction that I've used on screenshot.

Thanks for answer! It's what I need, I think, but for now it's not possible to me to implement what you said. I didn't write shaders code for know, only in vex bulider. Of coarse, my goal is to write shaders by myself, but now my level is quite low for this, I think. I've read Houdini help info about these functions and have understod some part of it, but it's not enough to implement this for now. About Mantra Surface - I want to make my own shader, which make only what I need. Mantra Surface is too "hard", a lot of useless functions for me. Even if I delete all I don't need from Surface Model inside it, like SSS etc, there is issue for me - Mantra Surface, as I think, made basically for PBR render(H13). I know that I can use micro-poligon render too, but all calculations are made by compute_lighting network, where is PBR-lighting node is situated. So, basically, all export calculations made from BSDF by this node. Not usable for me becouse I need particular render passes(image planes). I don't even need Beauty pass basically. And PBR-lighting export parameters is not usable for me(direct_diffuse etc.). I've made some tries and almost receive result that I need, but have made a decision to build my own shader. Sorry, I think my "noob" issues could be considered funny for hardcore Houdini artists, but I'm just preparing to move all my workflow to Houdini from some other CG software.

Oh, thanks for answer, using Mantra, but I've forget to say that I'm using micro-poligon rendering, PBR cannot be used for this work. For PBR Illuminance Loop doesn't need at all, as I know.

Hi everyone! Got new issue. Made shader - will not attach file, it's quite simple - just a standart Oren-Nayar diffuse connected to Cf output. Want to make diffuse and illumination passes from it. Made Parameter noder for this outputs of Oren-Nayar node. Added image planes and 2 simple light sources with different colors. Want to make passes for each light individually. But receive empty black passes when "For each light" toggle on. When off - got my pass, but for combined light. What I'm doing wrong? I know that there I should use Illuminance Loop node some how, but I haven't figured it out by myself. Houdini help didn't help, as Google. Tried to put my diffuse into Illuminance Loop and export parameters from it - doesn't work for me. Can you help me with this issue please?

Thank for answers, now I think that there is 2 ways to differ samples for render: shader-based and light-based, thats enough.

xrayThanks for answer! I have been exprerimenting with Image Planes for a long time and have got needed result. Unfortunately, don't remember it right now and my notes are at work, so I'll post it in this topic later(like 2 weeks). jordibaresThank you very much! I've been searching info like this for a lot of hours and haven't found anything usefull. Quick look on your link - that's what I neen on this stage of my work. Much appreciate! Will download now and dive in.

Just wanted to start a new topic, but my question is someting like TS's is. Can I vary pixel samples or min//max ray samples PER IMAGE PLANE basis? I've just founded hidden property which can be used for different indirect samples, but what about per image plane? For example, i've got diffuse, reflect and refract channels. Can I render diffuse with 2 min ray samples, reflect with 12 and refract with 8? Talking about PBR. Thanks! [ADD] In one render node, one pass.

Ok, I understand you. Next time - it will defenitely be next time - I'll do this. But in those particular situation it could be better explained by words. So, when you setting up your extra image planes, you may choose "Direct Lighting(per component)" - "direct_comp" VEX variable. And, as in my case, set "Export variable for each light". But if you don't need some components you should'n use "For each component" toggle. Just create an image plane and input VEX variable like "diffuse_direct", or "coat_direct" - if, for example, you don't need "reflect" component. And for lights - you could set particular light by editing "Light Mask" field. The * symbol means all light. You can exclude particular light by setting ^ symbol before its name. Or just delete * and add name of light you need. Attaching .hip files - it's very good practice, I totally agree! When you can dive in, explore it by yourself. But in my case I can't upload my file because of something like NDA and, unfortunately, I don't have a time right now to make an example.

It was so simple! I can just put names by different planes by myself individually. So obvious. I think, thread should be deleted.