Topics

16

[Max] Feature Requests / Separate 'Size' Value for Corona Sun Caustics

« on: 2023-10-18, 00:26:47 »

This might be a niche request but I'd love the ability to specify 2 different size values for the sun (or any lights) to control how caustics appear independently from shadows etc.

Example, I've got a scene where I've got the Corona Sun size set to 2.5, the shadows look great, but I hate the pool caustics.  They're just too blurry.  And vice versa, if I change the sun size to 0.1, the caustics look incredible but the shadows now too harsh.

I appreciate this would be the reality, but sometimes aesthetics beats physics.

So it would be great to have 2 settings in the Sun, Size (Shadows) and Size (Caustics)

17

[Max] I need help! / Objects with displacement disappear at high resolutions

« on: 2023-09-14, 23:36:42 »

I've got an image I'm trying to render.  In IR everything works fine.

If I do a production render at the main walls disappear if i go above 6k pixels on the longest edge.  6k is fine, 7k walls disappear

This only happens when displacement is enabled on the walls.

The displacement map is 11k.  But I've also tested with a smaller one and the same happens.

8k and 11k is probably overkill I know, but it still doesn't explain why it's disappearing in the main render but not IR.  Is there some threshold i'm unaware of somewhere?

I have 196GB of RAM and i'm not going anywhere near using it all so it can't be a ram issue.

18

[Max] I need help! / Caustics Issues

« on: 2023-09-14, 10:05:40 »

Can someone explain why caustics completely changes the appearance of my pool other than simply adding the caustic effect?

Without caustics the pool water is bright and has a nice colour to it.

With caustics the pool water gets darker overall and the colour drains out of it a bit so the whole pool becomes much 'muddier'.

Also my shadows completely change position.

Hopefully the screenshots show what I mean.  Ignore the small region that I used for testing dispersion.

19

[Max] I need help! / Texture Variations - Not Directly Corona Related

« on: 2023-09-13, 10:41:10 »

I have some high res scans of floor tiles, not many though.

Does anyone know of any clever ways to create more variations of a individual tile without simply photographing more of them which isn't an option at the minute?  i.e. can I feed an image of a single tile into say Midjourney or Substance and generate different versions of it to then use as part of a multitexture setup?

20

[Max] Resolved Bugs / Corona Bitmap Loader

« on: 2023-08-12, 20:47:36 »

Corona Bitmaps keep resetting the gamma override value.

If I manually specify to load a bitmap with a gamma override value of 1.  When I next click 'load bitmap', that setting is back on 'Automatic'.

This isn't not happening with standard bitmap.

Corona 10 HF1, Max 2024

It could be exclusive to this scene though, I don't normally use Corona Bitmaps but I'm using some Anima characters - to be honest it could be Anima itself, the software is so locked down, who knows what it's doing behind the scenes.

Really hoping for some positive Anima changes now that it's under the Chaos banner.

21

[Max] I need help! / Looking for workflow suggestions.

« on: 2023-08-10, 09:22:32 »

I've got a tricky job.

At the minute all I have to work with is some elevations and a very rough site plan.

It's a central courtyard surrounded by railway arches.  Photo attached.

Once the site is fully cleared, I'll be taking a photo from ground level.

The client then wants the arches to be occupied with glass fronts and bar/restaurant interiors.  They also want the external courtyard area to be populated with chairs/tables/people/food carts/planters etc etc.  Ultimately they want this space to look like a busy saturday afternoon.

How would you go about it?  Modeling everything isn't an option because we don't have the drawings/information to do so.  It also doesn't make sense because it exists and will be clean, new and empty when I take the photo.  So i'm thinking along the lines of shadow catchers or using camera map per pixel.  But in all honesty I'm not sure of the best approach.  I have a feeling it'll be a combination of the two and maybe even two separate renders.  The issue I have is the elevations are rough at best.  But that's all I have to work with.  That and the the photo i'll be taking once we get site access.

This is how I was going to go about it

Scene A Render A (The Arches)

Model the arch fronts and internals, model some dummy geometry for the arches themselves, move these into position as best i can using rough site plan and the photo as a guide in the viewport background

Model the paving and a basic version of the central stairs based on the rough site plan and the photo as a guide, create dummy geometry for the surrounding walls around the archways, populate the outdoor space - make all of this invisible to camera but cast shadows checked and visible to reflections/refractions checked.

Render.

Take this render and skew/move each archway into the correct position in the photo, they should be roughly correct to start with but won't be an exact match.

Scene B Render B (The Courtyard)

Make everything in the previous scene visible to camera again.

Delete the archways and internals

Cap the holes of the archways so i have a solid piece of dummy geometry represting the walls with the archways.

Apply shadow catcher material to dummy walls, dummy paving, dummy stairs.  All other entourage (table/chairs/people/food carts/planters) to be rendered as normal with normal materials.

Render

Drop this render at the top of the photoshop for file for Scene A and mask back in the arches


Does that make sense or is that massively overcomplicating things?  Would Camera Map per Pixel be a more useful approach?

22

[Max] I need help! / Best way to make something visible in reflections but not refractions

« on: 2023-08-06, 19:29:56 »

I'm rendering a scene that looks directly at a glass window.  The environment beyond the window will be replaced with photography.  I've modelled some dummy geometry to replicate the environment so that I get accurate shadows and reflections, but I don't want these dummy objects visible through the glass so that I can get a clean alpha for comping the backplate in later.

It's worth noting that I don't really want to use the Direct Override because there are other glass objects in the scene.  So is there a way to override just the refractions of the main window glass?

What's the best setup to achieve this?

23

[Max] I need help! / Caustics

« on: 2023-07-31, 23:04:56 »

Whenever I render pool caustics I always get these odd looking areas.  I don't really know how to describe other than it looks like the same effect you'd get on texture on the sides of a box if you applied texture mapping in planar mode rather than box.

I don't see them in any references photos of swimming pools etc.

The water is simply a flat piece of geometry displaced with Phoenix FD Ocean Tex.

So I'm wondering if its an artifact caused by Corona's displacement?

24

[Max] Bug Reporting / Tonemapping Order/Behaviour

« on: 2023-07-27, 15:50:31 »

Hi guys

Getting some funky results with various tonemapping combinations.

The effect of the Tone Curve operator appears to inverse depending on whether it's above or below the ACES OT Operator.

We've been advised to keep ACES OT at the bottom, so let's assume Tone Curve being above ACES OT is the correct way to go.

However, when I have it in that order, the settings appear to do the reverse of what I'd expect.  i.e. changing Highlights to 1.0 makes the highlights duller.  Changing them to -1.0 makes them brighter.

It's also have a strange effect on the bright spots in the HDRI.  The bright spots on the HDRI appear to adjust inversely to the bright walls.

So when I adjust the highlights to -1.0 the walls get bright, but the HDRI bright spots get dull.  When I adjust the highlights to 1.0, the walls get dull but the HDRI bright spots get brighter.

In the attachment, the very bottom image is the one that appears to be working as I'd expect it to, but that has the tone curve placed below ACES OT.

Confused .....

25

[Max] Bug Reporting / Corona Light Material kills IR

« on: 2023-07-19, 14:07:14 »

As the title suggests, Max 2024.1, Corona 10 Official

If I try to render while a Corona Light Material is active, IR just grinds to a halt and freezes up Max completely meaning I have to kill it via task manager.

I'm using CoronaAO in the Light Material Opacity slot to give a falloff to the illumination effect.

Update:  Removing the CoronaAO map allows everything to run as normal.

26

General CG Discussion / Shooting and Calibrating PBR Textures

« on: 2023-07-16, 14:18:37 »

Martin at Racoon Artworks has just published a great article over on his site.  It's a follow up to one he published a year ago.  Something I've often thought but never had the technical ability to verify but it seems those PBR ranges of between 30-50 might not be quite so 'safe' after all ....

https://www.racoon-artworks.de/blog_PBRshootingandcalibrating.php

I've proofread this for him, but if anyone more technical spots any errors then reach out to him.

27

Hardware / PC Spec for Realtime and Simulations

« on: 2023-07-14, 10:27:09 »

Disclaimer: I'm not technical at all so respond to me like I'm 5.

I want to spec a PC build that will used solely for realtime stuff i.e. Unreal Engine, and simulations i.e. Phoenix, Tyflow, Marvelous Designer.  And then rendering when not in use for anything else.

So far this is what I've spec'd but I love someone to sanity check this for me.

- ASUS TUF GAMING Z790-PLUS WIFI D4 - PCIe 5.0, 4x M.2, 2.5GbE/WiFi 6E
- Intel Core i9 13900KS, Raptor Lake, 24 Cores, 32 Threads, 3.2GHz Base, 6.0GHz Turbo
- Noctua NH-D15 Chromax Black - Quiet Performance Air Cooler
- 128GB (4x32GB) Corsair Vengeance LPX 3200MHz
- 24GB ASUS GeForce RTX 4090 TUF GAMING OC, 16384 Cores, 2565MHz Boost, GDDR6X - GeForce RTX VR Ready
- Corsair HX1000i, Modular, Silent, 80PLUS PLATINUM
- 1TB Samsung 980 PRO NVMe PCIe 4.0, 7000MB/s Read, 5000MB/s Write, 1000K IOPS
- 2TB Samsung 990 PRO NVMe PCIe 4.0, 7450MB/s Read, 6900MB/s Write, 1400K IOPS

Obviously budget is at the back of my mind, so I've opted for TUF over ROG where any Asus parts are involved.

The 1TB SSD is for Operating Systems and Software, the 2TB SSD is for cache files and the like.

The RAM is because the machine will also be used for rendering and my scenes often exceed 64GB on my other PC's (which all have 128GB in them).  However, can I run 4x 32GB sticks with this processor because I read - "The CPU supports up to 128 GB of memory in 2 memory channels."

The things I'm not sure on - the processor, the PSU, the cooling.  I've gone for the i9 as a compromise between cost/speed when compared to the Threadrippers.  Also because I read Speeds are more useful than Cores for this sort of thing.  The PSU I have no idea if this is enough wattage, the cooling again I have no idea.

Any help anyone can give would be much appreciated.

28

[Max] I need help! / Infinite Ocean/Displacement Issue

« on: 2023-06-26, 18:38:42 »

Anyone know why I get this hard cutoff when trying to do an infinite ocean with Phoenix/Corona?

29

[Max] Resolved Feature Requests / VFB History Notes

« on: 2023-06-23, 00:39:49 »

Would it be possible to add quick notes to the various snapshots in the VFB history?

30

[Max] Bug Reporting / Cancel DR render takes a long time to actually cancel

« on: 2023-06-22, 22:40:54 »

If you start up a DR render then cancel it shortly after it starting, it takes a long time to actually cancel.  This is mostly while the DR node is still in the "Scene Parsing" stage, it would be good if Corona could somehow send a 'kill' message to the DR node on pressing cancel.

If I remote desktop into the DR node and exit the server, it cancels immediately on the workstation that started the render.

Not sure if this is specific to Corona 10 or not.