Arnold rendering of MASH | color

complex procedure with fine result

this procedure is related to the problem of rendering Maya MASH Color node colours using Arnold. the workaround is complicated. pls don’t blame me. the tutorial where i demonstrate this is → here.

  • Create a MASH network from a Polygon object. Add a Color Node, play with the colour distribution.
  • Select the MASH_ReproMesh and assign a Shader of your choice, for example an Arnold Surface Shader. Set the colour to green.
  • In the ReproMesh-Attributes go to the MASH_ReproMeshShape tab und under Arnold → Export activate Export Vertex Colors.
  • Still in the ReproMesh Attribute editor, select the MASH_Repro tab and under → Output Attributes activate Color Per Vertex.
  • Display the Attribute editor of the shader you earlier assigned to the MASH_ReproMesh. You can do this by selecting the MASH network in the scene, then right mouse click and choose Material Attributes. It’s the green shader from earlier on.
  • Click on the checker icon next to Color and locate the aiUserDataColor node under the Arnold Utilities. Assign that node to the colour. It replaces the green from before.
  • Go to the MASH network node, select the Color tab, play with the colours – and render the scene with Arnold!

ian waters demonstrates the same procedure → here. he also pointed me to this tutorial of his which has nothing to do with the MASH Color Node, however: see → here.

brompton bike hire with | hiccups

brompton bike hire dock, turnham green, london

brompton is undoubtedly the best folding bike available these days. it folds wonderfully into a tiny packet, and it unfolds within seconds into a versatile, speedy city bike. the london based company intruduced a service a couple of years ago called → brompton bike hire. i have a brompton at home which i use every day, mostly in combination with tube or tram travel. but because the bike is slightly too large and quite a bit too heavy for taking it on board of a plane as handluggage, i’ve been an early adapter of the rental system in the UK. in 2016, when staying with my friend alison in pimlico, i had to travel quite far to get to the next rental dock. peckham rye that was, in the south of london. in the meantime we have rental hubs at king’s cross and several other locations around town. and not only around london: when arriving in oxford last year, i had googled for bike rental and made a reservation with → donkey bikes – but i was unable to find the bike in the bike parking lot in front of the railway station. instead i saw a brompton dock, canceled the donkey bike reservation, used the brompton rental app, opened box #9 and drove off to the university campus, quite far away, all across the old town. lovely ride with a bike i was very much used to anyway.

this time, when visiting friends near kew gardens, i chose the turnham green brompton hub depicted above. the app provides you with a long number which you punch into the keyboard on the left – and press enter. in most cases the UI did not show a green light after that procedure, so i had to repeat the process a few times. i think it has to do with the keys on the keyboard which react differently to pressure, and there’s no display which gives you feedback. nevertheless, the rental process is easy, i took the bike out of box #1, and off i rode.

what creates tension is when returning the bike. for only 3.50 pounds you can rent it for a whole day. i returned to the turnham green station a couple of hours later, folded the bike, punched in my reservation code, and nothing happened. then i remembered i had to do something in the app. the app, however, only showed me options to rent a bike, not for returing a bike. i phoned the service hotline. an automated reply stated: no avail, nobody to talk to. next i read the instructions on hub again. they are slightly confusing (rental, returning) and don’t tell anything about the usage of the app on the smartphone. in the meantime the app offered the option to return the bike and asked where i wanted to return it? i happily selected “turnham green” from the menu, and was thrown back to a page where i could make a new reservation or cancel a reservation. both did not make sense to me.

10 minutes had passed. so i followed the instructions on the box and sent a text message (xxxx now yyyy, where xxxx is the number engraved on/in the hub and yyyy is my personal pin; gee, where did i store my personal brompton bike rental pin?) to the given number. according to the instructions on the dock we should allow 5 minutes for the text message with the opening code to appear. nothing appeared on my phone. i rang the hotline again – with no help whatsoever. noone to talk to.

then i opened the app again, which, to my surprise, now presented me an opening code – which worked after the second time of punching the numbers in. box #1 opened, i lifted the bike in, saddle facing away from me, closed the box, and off i went. neither the app nor a text on the phone or an email informed me that the process was successfully finished. this is problematic indeed because you need to be sure that you actually checked out. when i rent a car2go smart car, i always wait until a green light shows in the window shield, which means, it is available for the next customer and done with me.

brompton certainly has to work on this. i’ll post their reply here once they’ve read this blog entry.

brompton bike hire oxford, screenshot

here’s my own tempest blue, → at 280 km/h. ;-)

the fine light by | 32bitStudios

more about → this discovery later. it’s basically a 3D scene with nothing but a pipe and several lights and cameras. you switch them on and off. i created mainly superellipse objects for these test renderings. each image took about 15 minutes to render using → arnold in → maya 2018.

test rendering with 32bitstudio intro light and some “super” objects


details from the above arnold rendering

second test rendering, same light

more or less the same objects, soft diffuse light setting

same scene, different light setup

another lighting setting for the same scene

detail from the picture above. took 19 minutes to render.

dimensions in 3D computer | graphics

dimensions and proportions are extremely imporant in 3D computer graphics. the spaceship, the walking man and the cars all come in the same size, very big compared to the mountain range in the background. we have to scale things properly in order to make the scene work. here is my → tutorial about dimensions in 3D.

3D scene with big and small objects

motion blur helps guiding the viewer into the dramatic scene.

unter der | drohne

diese drei fotos sind einem video entnommen, das ich mit einer unten an die drohne angehängten 360° kamera aufgenommen habe, einer → ricoh theta V. das video war zu stark verwackelt, um es irgendwo zu posen. das wackeln lag nicht an der drohne oder der kamera, sondern an der geometrischen anordnung: die kamera hängt ca. 15 cm nach unten, das ist aerodynamischer quatsch, funktioniert im prinzip aber. ich schätze, selbst bei geringem wind wird die kamera ordentlich wackeln, weil die drohne darüber ja eh laufend die horizontale austariert.

das erste einzelbild ist ein tatsächliches 360° panorama. wenn man nach oben guckt, sieht man die drohne, unten den park, den sportplatz etc. wer köln kennt, sieht den dom, das unicenter, den deutschlandfunk etc. ich habe das foto aus final cut pro X am mac als einzelbild exportiert. die beiden fotos darunter sind einfach screenshots aus der theta-app.

drohne über köln

drohne kehrt zurück